Effect of surface modification methods on dentin-resin bond strength after amalgam contamination: In-vitro study

Effect of surface modification methods on dentin-resin bond strength after amalgam contamination: In-vitro study | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Research Article Effect of surface modification methods on dentin-resin bond strength after amalgam contamination: In-vitro study Cem PESKERSOY, Hilal BUCEKLER, Murat TURKUN This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7115069/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract Background The aim of this study was to investigate the bond strength of resin composites to dentin surfaces following the removal of amalgam restorations. Methods Twenty-seven amalgam-restored molars were selected, and their amalgam restorations were removed. The exposed dentin surfaces were subjected to different surface treatments: ortho-phosphoric acid etching, sandblasting, and Er:YAG laser irradiation. Following surface treatment, the samples were divided into three subgroups and restored using different universal adhesives (Solare Universal Bond, Gluma Bond Universal, Scotchbond Universal Plus) and nanohybrid composite resins (G-aenial A'CHORD, Charisma Topaz, Filtek Z550). Microshear bond strength (µSBS) testing was conducted for each group. The data were statistically analysed using one-way analysis of variance (ANOVA) and Tukey’s post-hoc test. Results The highest bond strength was observed in the 3M subgroup (39.91 MPa) on laser-treated dentin surfaces, while the lowest bond strength was recorded in the Kulzer subgroup (3.61 MPa) on sandblasted surfaces. Conclusions Surface modification of amalgam-contaminated dentin, particularly with laser treatment, enhanced the adhesion of composite resin and yielded successful bond strength outcomes. Amalgam contamination Composite resin Adhesive system Dental laser Bond strength Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 BACKGROUND Following developments and current approaches in dentistry, the clinical use of metal alloy restorative materials such as amalgam is gradually decreasing [ 1 ]. Important factors such as allergic and autoimmune reactions such as lichen planus caused by amalgam restorations, incompatibility of aesthetic and mechanical properties with dental tissues, mercury content and the related material not being sufficiently biocompatible are the most common reasons for amalgam replacement as stated in Minamata declaration [ 1 , 2 ]. Composite resins have long stood in the breach as a viable alternative to dental amalgams, offering materials that do not require mechanical retention within the cavity and that bond to the tooth surface through micromechanical adhesion. [ 3 , 4 ]. The hybrid layer formed by the hydrophilic monomers of the adhesive and the collagens exposed on the tooth surfaces (adherent) as a result of different surface roughening processes, especially acid etching, forms the basis of this adhesion process [ 5 ]. The main factors affecting adhesion are surface energy, contact angle, wettability, the presence of a smear layer and the number and condition of the tubules in the dentin tissue [ 6 , 7 ]. Surface treatments applied before adhesive bonding to mineralized dental tissues contribute to the adhesion of resin composites to the adherent material. Traditionally, the application of orthophosphoric acid is regarded as the gold standard among chemical surface conditioning methods [ 8 ]. Although the duration of the pickling process varies according to the case and material, prolonged pickling of the enamel creates a deep roughened area, and the adhesive cannot spread over this roughened area. This leads to the formation of dead spaces and may result in discolouration and secondary caries formation at the edge of the restoration [ 9 ]. Mechanical surface preparation methods such as diamond burs, sandblasting and air abrasion can produce micro- and macro roughening of the tooth surface with aluminum oxide particles or diamond particles pushed at high speed [ 10 ]. Dental lasers, which have recently become widespread, are another method used for surface modification. Er:YAG and Er,Cr:YSGG laser systems vary in the depth of roughness they create on the surface according to different wavelengths and pulse numbers [ 11 ]. Laser irradiation, which is applied to the tooth surface causes the water content within the hydroxyapatite matrix evaporate and dehydration [ 12 ]. Unlike enamel, dentin has a tubular structure and contains moisture, which makes adhesion to dentin more challenging in terms of “exposing the peritubular and intertubular dentin without demineralizing” and “avoiding smear layer formation” [ 13 ]. Current adhesive systems aim to strengthen adhesion to dentin, and for this purpose, the contents of the materials are constantly being improved. The 8th-generation universal adhesive, which shortens the clinical study time, is claimed to strengthen adhesion. Some of the monomers in the content of the 8th generation universal adhesives include 4 methacryloxyethyl trimelliate anhydrides (4-META), methacryloxyethyl phenyl hydrogen phosphate (MEP-P), methacrylolsipropyl dihydrogen phosphate (MMP), methacryoloxyethyl dihydrogen phosphate (MEP), 10-methacryloyloxy decyl phosphate (10-MDP), 2-hydroxyethyl methacrylate (HEMA), silane, methacryloloxyalkyl acid phosphate (MAC-10), vitre bond copolymer, glycerol dimethacrylate ester (GPDM), and dipentaerythrolpentaacrylol dihydrogen phosphate (PENTA-P) were developed to increase adhesion in secondary treatments such as absence of sound dentin, restoration repairs and renewals [ 9 , 14 ]. HEMA monomers are prone to hydrolysis and absorption because of their hydrophilic structure, and HEMA and bisphenol A (BPA) monomers can cause cytotoxic and allergic reactions [ 14 , 15 ]. The aim of this study was to restore the affected dentin tissue after the removal of amalgam restorations using different surface modification methods and different universal adhesive systems and to compare the bond strengths. The first hypothesis (h1) of the study is that there will be a difference between the bond strengths of restorations made via different surface modification methods, and the second hypothesis (h2) is that there will be a difference between the bond strengths of restorations made via different universal adhesive systems. METHODS In this study, 27 caries-free human molars without surface fractures or microcracks were used. Local protocols reviewed and approved by the Ege University Ethics Committee (reg no: 24-7T/52) were followed and informed consent formed was secured from all participants. The post-extraction residues on the surfaces of the teeth were cleaned mechanically, disinfected with 5% sodium hypochlorite solution for 24 hours and then stored in 0.025% thymol solution at room temperature until the completion of the test and measurement stages. The materials used in this study are shown in Table 1 , the experimental flow chart of the samples is shown in Fig. 1 . Table 1 Materials used in the study and their contents Material Manufacturer Classification LOT No Composition Solare Universal Bond GC, Tokyo, Japan Universal Adhesive 2309044 4-META, silanated colloidal silica, UDMA, TEGDMA, 10-MDP, acetone (25–50%), water (> 20%), initiators Scotchbond Universal Plus 3M Oral Care, St. Paul, MN, USA Universal Adhesive 10517802 Bis-GMA, 10-MDP, 2-HEMA, Vitrebond copolymer, ethanol, water, initiators, fillers Gluma Bond Universal Kulzer, Hanau, Germany Universal Adhesive NO10068 10-MDP, 4-META, Bis-GMA, 4-ethyl dimethyl aminobenzoate, cetylamine hydrofluoride, initiator, acetone (25–50%), water G-aenial A'CHORD GC, Tokyo, Japan Nano Hybrid Resin Composite 2007021 Bis-MEPP, filler load: 82% by weight: Glass-filler (300 nm barium glass) 16 nm (fumed silica), organic filler (300 nm barium glass; 16 nm fumed silica) Filtek Z550 3M/ESPE, St. Paul, MN, USA Nano Hybrid Resin Composite 10297071 Bis-GMA, Bis-EMA, PEGDMA, TEGDMA, UDMA, surface-modified zirconia/silica fillers, nonagglomerated / nonaggregated surface modified silica particles. Charisma Topaz Kulzer, Hanau, Germany Nano-Hybrid Resin Composite N010220 Barium aluminum fuoride glass (0.02-2 µm), TEGDMA 5 vol% pyrogenic, UDMA, TCD-DI-HEA silicon dioxide 0.02–0.07 µm, Condak 37 FGM, Joinville, SC, Brazil 37% phosphoric acid 37% phosphoric acid, thickener, pigment and deionized water *Information provided by the manufacturers. 4-META: 4-methacryloxyethyl trimelliate anhydride; UDMA: urethane dimethacrylate; TEGDMA: triethyleneglycol dimethacrylate; 10-MDP: 10-methacryloyloxydecyl dihydrogen phosphate; Bis-GMA: bisphenol A glycidyl methacrylate; 2-HEMA: 2-hydroxyethyl methacrylate; Bis-MPEPP: 2, 2′-bis(4-methacryloxy polyethoxyphenyl) propane; BIS-EMA: ethoxylated bisphenol A glycol dimethacrylate; PEGDMA: polyethylene glycol dimethacrylate; TCD-DI-HEA: Bis-(acryloyloxymethyl) tricyclodecane. Preparation of Samples The crowns of all teeth were removed from the occlusal 1/3 in the horizontal direction with the help of a 4 mm thick isomet saw (Buehler Ltd., Lake. Bluff, IL, USA) in the horizontal direction to reach large dentin sections in the coronal region of the teeth where the composites would be applied. The crown sections were fixed in cylindrical Teflon molds with an inner diameter of 14 mm, an outer diameter of 22 mm and a height of 14 mm, with the enamel and dentin surfaces above and parallel to the ground plane, leaving a gap of at least 2 mm from the incisal surface, with fast-setting repair acrylic. Amalgam restorations were applied to the samples without a 2 mm cavity wall remaining on the occlusal surfaces of the molds and with a dentin surface only at the base. After the Teflon molds were removed, the samples were subjected to natural aging in artificial saliva solution for 5 years. The artificial saliva used was prepared to simulate the composition of Fusayama-Meyer’s artificial saliva solution. The formulation consisted of distilled water (1L), KCl (0.4 g/L), NaCl (0.4 g/L), CaCl₂·2H₂O (0.906 g/L), NaH₂PO₄·2H₂O (0.690 g/L), Na₂S·9H₂O (0.005 g/L), and urea (1.0 g/L), with the pH adjusted to 6.5. The solution was renewed weekly. After aging, the amalgams were removed from the tooth surfaces with hand tools (excavators) and placed in an oven at 37°C for 24 hours between all steps to prevent dehydration. Separation of samples into groups The grouping of the samples is schematized in Fig. 2 . The prepared samples were divided into 4 groups according to the surface modification / roughening processes to be applied: Group 1 Acid etching; 37% ortho-phosphoric acid (Condak 37, FGM, Joinville, SC, Brazil) application, Group 2 Air-abrasion (Air-prophy unit, Stardent Equip. Co. Ltd., Gongfu, China) sandblasting with aluminium oxide fragments, Group 3 : Er:YAG dental laser (LightWalker AT, Fotona, Ljubljana, Slovenia) device roughening in non-contact mode, Group 4 Control group; group without surface modification. Surface Preparation For the group 1 samples, the dentin tissue was etched with 37% orthophosphoric acid for 15 s, washed with the air‒water spray of the dental unit for the same amount of time and dried with light compressed air. In Group 2, the tooth surfaces were roughened via standard parameters (particle size: 50 µm, distance: 10 mm, angle: 90 \(\:^\circ\:\) and pressure 70 ± 2 psi) with abrasive powder containing aluminum oxide. During sandblasting, other areas on the same sample were covered with dental transparent silicone to prevent particle scattering, and sandblasting was performed in this way. After sandblasting, the samples were thoroughly washed for 10 s via a dental unit air‒water syringe and dried with light compressed air. In Group 3, dentin tissue was modificated with an Er:YAG laser (LightWalker AT, Fotona Medical Lasers, Ljubljana, Slovenia) with a wavelength of 2.94 mm, a frequency of 20 Hz and a pulse duration of 100 ms (medium short pulse) in non-contact "etching mode" using fixed parameters (power: 4 W, energy: 200 mJ) at a distance of 7 mm from the dentin surface under water cooling (50 ml/min). The selected parameters (4 W power, 200 mJ energy, 20 Hz frequency, 100 µs pulse duration) were based on previous studies demonstrating their effectiveness in optimizing surface roughness and enhancing micromechanical interlocking, which plays a crucial role in the bond strength between aged composite resin and the repair material. Construction of Composite Blocks The samples were randomly divided into 3 subgroups according to the adhesive system and compatible resin composite material (n = 9): Subgroup GC Solare Universal Bond (7th generation adhesive) + G-aenial A'CHORD (nanohybrid composite), (GC Dental Corp, Tokyo, Japan), Subgroup 3M Scotchbond Universal Plus (8th generation adhesive) + Filtek Z550 (nanohybrid composite) (3M ESPE, St. Paul, MN, USA). Subgroup HK Gluma Bond Universal (7th generation adhesive) + Charisma Topaz (nanohybrid composite) (Heraus Kulzer GmbH, Hanau, Germany), After surface preparation, resin composite blocks 2 mm in diameter and 5 mm in height were prepared using a universal jig (Ultradent, South Jordan, UT, USA). For this purpose, universal adhesives and composite resins were applied to each group according to the manufacturer's instructions. In subgroup GC, the adhesive Solare Universal Bond (GC, Tokyo, Japan) was applied to the dentin surface with a rubbing motion for 10 s, dried slightly with air spray and polymerized with an LED light device (Bluephase 20i; Ivoclar Vivadent, Schaan, Liechtenstein) with a light power of 1200 mW/cm 2 for 20 s. Then, the G-aenial A'CHORD (GC, Tokyo, Japan) nanohybrid composite was placed in the jig in 2 mm layers and polymerized for 20 s each time. In subgroup 3M, Scotchbond Universal Plus (3M ESPE, St. Paul, MN, USA) was applied to the dentin surface with a disposable applicator for 20 s with a vigorous rubbing motion. Then, the adhesive was spread on the tooth surface with light pressure for at least 5 s and polymerized for 10 s with an air spray until the adhesive layer formed a non-moving glossy film. Filtek Z550 (3M ESPE, St. Paul, MN, USA) nanohybrid composite was then applied in 2 mm layers into the jig and polymerized for 20 s each time. In subgroup HK, Gluma Bond Universal (Heraus Kulzer GmbH, Hanau, Germany) was applied to the cavity with a soft brush and gently rubbed for 20 s, then air dried until no fluid movement was detected and polymerized for 10 s. Charisma Topaz (Kulzer, Hanau, Germany) nanohybrid composite was subsequently placed in the jig in 2-mm layers and polymerized for 20 s each time. The samples were inspected with a light microscope (S8 APO, Leica Microsystems GmbH, Wetzlar, Germany) at 10x magnification to check for any layering defects. During this examination, any defects, abrasions, visible air pockets or bonding problems on the composite block and tooth surfaces were carefully reviewed, and specimens with problems were excluded from the study. Microshear Bond Strength (µSBS) Test The composite blocks were subjected to shear tests with a universal testing machine (AG-50kNG, Schimadzu, Tokyo, Japan) using a (thick knife-edge type blade) with specified test parameters (tip speed: 1.0 mm/min, maximum load: 50 kg/cm 2 ). The failure loads (MPa) and the maximum applied load (N) were recorded. The fracture types (adhesive, cohesive, mixed, composite fracture) were recorded as a result of the bond strength test by examining the fracture types formed on the sample surfaces as a result of the fracture test under a light microscope at 2.5X and 10X magnifications. Scanning Electron Microscopy Images and Determination of Fracture Types After the crushing test, the changes on the sample surfaces and the amalgam residues remaining on the surfaces were examined by scanning electron microscopy (SEM) (Apreo S SEM, Thermo Scientific, The Netherlands) at a low vacuum of 150 millitorrs, a filament voltage of 10 kV and magnifications of 1000, 5000 and 10,000. Statistical Analysis All the data obtained were transferred to statistical analysis software (SPSS, vers. 27.0 IBM, Chicago, IL, USA), the data obtained from each test method were first examined for homogeneous distribution using the Kolmogorov-Smirnof test and the minimum, median, maximum and mean values of the samples were determined. The alpha value was calculated as p = 0.05 . The analysis indicated that the laser group (p = 0.200), acid etching group (p = 0.191), control group (p = 0.200), and sandblasting group (p = 0.121) exhibited a homogeneous distribution, allowing the application of one-way ANOVA with post hoc Tukey test to all groups. RESULTS Microshear Bond Strength Results Table 2 shows the means and standard deviations of the strength variables of the groups. The µSBS values of the surface modifications and adhesive systems used are shown in Fig. 3 . When all the groups were evaluated in the present study, the highest mean bond strength was measured in the Er:YAG laser group (30.88 ± 5.19 MPa), followed by the acid etching (26.50 ± 3.77 MPa), control (20.68 ± 4.75 MPa) and sandblast groups (11.51 ± 4.47 MPa) ( p = 0.000 ). According to the bond strength test results of the composite resins after surface modification, a significant difference was found between all the groups (p = 0.000 ). While there was no significant difference among the GC, 3M and HK subgroups in the sandblasted samples ( p > 0.05 ), the lowest bond strength among all the samples was measured in the sandblasted + HK subgroup (3.61 MPa) (Table 2 ). Among the 3M samples, there was no significant difference between the sandblasting group and the control group ( p = 0.519 ), but lower bond strength results were obtained, unlike those of the other modification methods, acid etching and laser groups ( p = 0.000 ). Table 2 Bond strength values obtained from the study and significant differences Composites Surface Modification Minimum Maximum Mean SD P GC Acid etch 21.58 31.12 27.64 b 2.90 0.001 M. Blasting 5.94 20.48 10.79 a 4.08 Er:YAG Laser 25.48 37.18 31.14 b 3.83 Control 21.54 34.62 25.54 b 4.45 3M Acid etch 22.17 32.99 28.93 a 3.45 0.001 M. Blasting 10.09 19.72 14.13 b 3.26 Er:YAG Laser 29.98 39.91 34.86 a 3.36 Control 14.38 22.01 18.12 b 2.37 HK Acid etch 19.51 27.45 22.93 a 2.30 0.001 M. Blasting 3.61 18.28 9.61 b 5.27 Er:YAG Laser 20.15 33.14 26.62 a 5.16 Control 12.35 23.87 18.38 c 3.31 * The mean shear bond strengths with different superscripts for the same material shows significant differences ** SD: Standard deviation. *** Minimum (underlined) and maximum (bold + italic) shear bond values were emphasized in the table. While there was a significant difference between the laser and sandblasting ( p = 0.000 ) and control ( p = 0.038 ) groups, there was no significant difference between the laser and acid groups ( p = 0.708 ). Similarly, in the 3M subgroup, there was no difference between the laser and acid groups ( p = 0.635 ), and more successful results were observed than in the sandblasting ( p = 0.000 ) and control ( p = 0.001 ) groups. There was no significant difference between the GC and 3M subgroups or between the GC and HK subgroups for the samples modified with the dental laser surface, but the 3M subgroup presented better bond strength than did the HK subgroup ( p = 0.001 ). Among the laser-treated samples, the highest bond strength was observed in the 3M subgroup (39.91 MPa). When the samples in the GC and HK groups were evaluated within themselves, a significant difference ( p = 0.000 ) was observed only between the acid etching and sandblasting groups. Among all the samples etched with acid, a significant difference was found only between 3M and HK subgroups ( p = 0,045 ). The highest bond strength in the acid-etched samples was found in the 3M subgroup (32.99 MPa). Classification of Failure Types Following the µSBS test, the failure types observed in each group were visualized with light microscopy (DM 500 RH, Leica Camera AG, Wetzlar Germany). The most common failure type observed in this study was adhesive fracture (54.62%), and there was a statistically significant difference between surface modifications ( p < 0.05). Unlike the other groups, cohesive and composite fracture types were not observed in the control group, whereas adhesive fracture was the most observed failure in the acid and control groups. While there was no statistically significant difference between the adhesive subgroups ( p > 0.05) , surface modification methods were found to have an effect on determining fracture type. (Fig. 4 ) Scanning Electron Microscopy Evaluation After the removal of the amalgam restorations, partial traces of amalgam contamination and particle residues were observed on the dentin surface of all the samples (Fig. 5 ). After surface modification, amalgam contamination was found to be the highest, especially in the sandblasting and control group. Compared with those on the other surface modification methods, fewer smear layer was observed on the dentin surfaces modified with the Er:YAG laser. Besides, the deformation caused by the Er:YAG laser in the dentin tissue due to high heat and ablation is also observed. Compared with those of the other groups, the sandblasted samples presented more irregular peritubular dentin on the dentin surface, and the specific shape created by the roughening process and aluminium oxide particles are also observed. For the control group, the smear layer covered the entire dentin surface and therefore the dentinal tubules could almost not be observed. DISCUSSION In this study, sandblasting, acid and laser surface modification methods were applied to the affected dentin tissue after amalgam filling removal in aged teeth and restored with different universal adhesive systems with different nanohybrid composites, and the bond strengths were compared. Dentin tissue without surface modification was used as a control group. Based on the results of this study, dentin surface treatments generally affect the bond strength. In particular, the bond strength was found to be significantly higher in the laser-treated samples; therefore, hypothesis h1 was accepted. In addition, the secondary hypothesis that there would be a difference in bond strength between different universal adhesive systems was also accepted. The colouration of dental tissues caused by the corrosive products of amalgam and the presence of these products negatively affect adhesive bonding. Nojoud Alshehri et al. reported that, compared with that of unaffected dentin, the adhesion of bulk-fill composite resin to amalgam-affected dentin yielded negative results [ 16 ]. Harnirattisai et al. and Ghavamnasiri et al. reported similar results indicating that the most likely explanation is the formation of a sclerotic dentin layer and the restriction of the formation of resin tags by blockage of dentin tubules with corrosive products such as Sn, Zn and Cu in the amalgam structure [ 17 , 18 ]. These corrosive products have been shown to cause the precipitation of plasma proteins into the dentin fluid, reduce dentin permeability, and increase the difficulty of removing the smear layer of amalgam-affected dentin [ 19 , 20 ]. According to the results of these studies, clinical procedures should be determined by considering the different structures of the affected dentin after amalgam removal. SEM revealed that a significant number of particles remained in the dentinal tubules after amalgam removal in each group, and these particles negatively affected the bond strength. In this respect, our results are consistent with studies in the literature. Different surface modification procedures can be applied to dentin tissue to strengthen adhesion especially acid etching. Adhesion of the composite resin to the dentin surface is achieved by micromechanical locking with resin tags in the gaps on the dentin surface after acid application [ 10 ]. By increasing the surface area with sandblasting, adhesion to the dentin surface is strengthened by increasing the surface energy. However, there are also studies showing the opposite results in the literature. The surface properties abraded by sandblasting differ chemically from those of acid-etched surfaces, and some studies have shown that aluminum oxide particles remain in the dentin tubules and are thought to clog the tubules [ 10 , 21 ]. In this study, the bond strength obtained from the sandblasted samples was the lowest, and the most likely reason for this was that the sandblasting process with aluminum oxide particles negatively affected the tubule structure and the stability of the collagens. In this study, an Er:YAG laser was used as another surface roughening method. Although many studies in the literature have investigated the bond strengths to dental hard tissues via the Er:YAG laser, the results obtained from these studies are contradictory and even controversial 2 [ 21 , 22 ]. Some researchers claim that the dental laser increases adhesion because it expands the bonding area available on dentin surfaces, vaporizes the lymph fluid in the dentinal tubules in a controlled manner, and creates a clean dentin surface free of a smear layer [ 23 , 24 ]. In addition, studies have suggested that adhesion is lower because more collagen destruction results from acid etching than from the use of a dental laser [ 25 ]. In recent studies, Er:YAG laser application has been reported to change the dentin surface and thus the bonding mechanism of adhesives to dentin, and a smooth dentin surface can increase the bond strength between dentin and resin 1 [ 11 , 26 ]. The results of the present study revealed that the Er:YAG laser applied in surface modification mode left fewer smear layers in the dentin tissue; thus, the "resin tags" formed by the adhesive systems in the dentin tubules were greater in volume. In this respect, our results support current studies. The most recent group of adhesives, Generation 8 universal adhesives, work with a similar mechanism to traditional one-step self-etch adhesives, but their activity is modified by the pH of their acidic monomers. Unlike universal adhesives, they contain carboxylate and/or phosphate functional monomers. Among these monomers, 10-MDP ionically binds to dentin by forming dissolution-resistant calcium salts on hydroxyapatite in the form of nanolayers 27) . In addition, 10-MDP is an important monomer that is the most resistant to hydrolytic degradation among other functional monomers, strengthens chemical bonding and can also chemically bond with zirconium oxide [ 27 ]. According to long-term studies, when universal adhesives are applied in self-etch mode, more stable chemical bonding is achieved when the samples are aged depending on the monomers they contain, such as 10-MDP [ 27 , 28 ]. Hydrophilic monomers such as HEMA in adhesives are known to reduce adhesion by increasing the susceptibility of the bonding interface to hydrolytic and enzymatic degradation 29) . Therefore, monomers such as hydrophilic HEMA and allergenic BPA have been removed from new universal adhesives. In this study, the BPA-free adhesive was found to provide better bond strength than the other 8th generation adhesives did, and this result is consistent with studies in the literature [ 30 ]. Tang. et al. reported that the superior bond strength results of BPA-free adhesives in their bonding strength tests could be attributed to the synthesis of Bis-GMA alternatives, which exhibit equivalent or even superior crosslinking potential and mechanical properties [ 14 ]. Found that while BPA-free adhesives demonstrated similar bond strength to other adhesives in their study, they formed more resin tags, reduced polymerization shrinkage, and enhanced bond quality by increasing conversion rates. These improvements were associated with the inclusion of the G-IEMA monomer, which features a three-dimensional structure composed of eight polymerizable methacrylate groups. In the current study, the manufacturer of the Scotchbond™ Universal Plus BPA-free adhesive claims that it contains HEMA (2-hydroxyethyl methacrylate) and Bis-GMA (bisphenol A glycidyl methacrylate) dimethacrylate resins, but states that Bis-GMA is BPA-free, consisting of crosslinkable and radiopaque monomers, with no BPA in the formulation. While detailed composition information has not been disclosed, this enhanced monomer structure could be linked to the high bond strength results observed in this study. Following the removal of amalgam restorations, metal ions such as tin may accumulate within the dentinal tubules, leading to their occlusion, reduced permeability, and consequently diminished resin tag formation [ 17 ]. In the present study, BPA-free adhesives demonstrated superior bonding performance on these modified surfaces, which may be attributed to enhanced tubular infiltration. Composite resins have different mechanical properties, such as compressive strength, modulus of elasticity, and microhardness, depending on the number of particles, size and type of filler they contain [ 31 ]. Many materials, such as micro- and nanoparticle composites and hybrid composites, have been developed because classical macrofil composites are not polished well, undergo rapid colour changes, and are not resistant to occlusal wear 6) . Nanohybrid composites meet the aesthetic expectations of patients while increasing the surface properties of restorations. In addition to their good polishability and good aesthetic properties, they are durable materials with low polymerization shrinkage [ 32 ]. Özcan et al. compared the bond strengths of microhybrid and nanohybrid resin composites and reported that they had similar bond strengths [ 33 ] Brkanovi´c et al. measured the bond strength of universal adhesives to dentin and reported a significant difference between the Scotchbond Universal Plus (3M ESPE) and G2-Bond Universal (GC) groups. In this study, the bonds in the GC subgroup were greater than those in the 3M subgroup without surface treatment [ 29 ]. The greater results of the 3M subgroup in samples with surface modifications should be taken into consideration in clinical use. Ouchi et al. examined the bond strength of universal adhesives after sandblasting and reported a lower bond strength on sandblasted dentin surfaces [ 34 ]. Similar to the results of this study, the G-Premio Bond (GC) group presented lower results than did the Scotchbond Universal (3M) subgroup. Considering all the results, the 3M subgroup is the most effective method of laser surface modification of amalgam-affected dentin, providing high bond strength to dentin compared with other adhesives. CONCLUSION Composite resins are the preferred restoration material in cases such as the presence of secondary caries, aesthetic reasons, fractures or edge incompatibilities where amalgam must be removed. One of the most important criteria for the success of composite restorations is ensuring adhesion. Amalgam-affected dentin is sclerosed and contains amalgam residues. Various surface roughening procedures, especially laser application, strengthen the adhesion of the composite to the dentin tissue. However, sandblasting, which smooths the surface owing to its abrasive nature, has a decreasing effect on the bond strength. On the other hand, HEMA and BPA-free 8th generation adhesives were successful in terms of bond strength and penetration into dentin. HEMA- and BPA-free generation 8 adhesives with surface modification methods are recommended for these cases, for which there is no recommended procedure in clinical practice within the limits of the study. Abbreviations • 10-MDP 10-methacryloyloxy decylphosphate • 4-META 4-methacryloxyethyl trimellitate anhydride • BPA Bisphenol A • Er YAG:Erbium-doped yttrium aluminum garnet • G-IEMA Glycerol-based isosorbide ether methacrylate • GPDM Glycerol phosphate dimethacrylate • HEMA 2-hydroxyethyl methacrylate • MAC-10 Methacryloloxyalkyl acid phosphate • MEP Methacryloxyethyl dihydrogen phosphate • MEP-P Methacryloxyethyl phenyl hydrogen phosphate • MMP Methacrylolsipropyl dihydrogen phosphate • µSBS Microshear bond strength • PENTA-P Dipentaerythritol pentaacrylate phosphate • SEM Scanning electron microscopy Declarations Ethics approval and consent to participate: This study was approved by the Ethics Committee of Ege University Faculty of Dentistry (Approval No: 24-7T/52). All procedures involving extracted human teeth were performed in accordance with the ethical standards of the institutional and/or national research committee. Informed consent to participate was obtained from all the participants. Consent for publication: Not applicable. Availability of data and materials: The datasets generated and/or analysed during the current study are available from the corresponding author on reasonable request. Competing interests: The authors declare that they have no competing interests. Funding: This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors. Authors’ contributions: HB contributed to sample preparation, surface modification procedures. CP contributed to the study design, data interpretation, statistical analysis and manuscript supervision. MT contributed to the methodological planning, result interpretation, and final manuscript revision. All authors read and approved the final manuscript. Acknowledgements: Not applicable. Authors’ information: HB is a PhD student and research assistant at the Department of Restorative Dentistry, Ege University, Turkey. CP is an Associate Professor in the same department, specializing in adhesive and restorative dentistry. MT is a full Professor of Restorative Dentistry with extensive experience in dental materials research. References Mackey TK, Contreras JT, Liang BA. The Minamata convention on mercury: Attempting to address the global controversy of dental amalgam use and mercury waste disposal. Sci Total Environ. 2014;472:125-9. Tibau A, Grube B. Dental amalgam and the minamata convention on mercury treaty: Make mercury history for all. J Oral Dent Health. 2023;7(3):227-41. Antoniadou M, Varzakas T, Tzoutzas I. Circular economy in conjunction with treatment methodologies in the biomedical and dental waste sectors. Circ Econ Sustain. 2021;1(2):563-92. Ünlü N, Ülkü SG. Composite resin restorations in the last 10 years: A review with in vivo and in vitro studies. NEU Dent J. 2020;2(3):124-45. Kazak M, Dönmez N. Development of dentin bonding systems from past to present. Bezmialem Sci. 2019;7:322-30. Perdigão J, Araujo E, Ramos RQ, Gomes G, Pizzolotto L. Adhesive dentistry: Current concepts and clinical considerations. J Esthet Restor Dent. 2021;33(1):51-68. Thalacker C. Dental adhesion with resin composites: A review and clinical tips for best practice. Br Dent J. 2022;232(9):615-9. Szerszeń M, Higuchi J, Romelczyk-Baishya B, Górski B, Łojkowski W, Pakieła Z, et al. Physicochemical properties of dentine subjected to microabrasive blasting and its influence on bonding to self-adhesive prosthetic cement in shear bond strength test: An in vitro study. Materials (Basel). 2022;15(4):1476-94. Çelik A, Bingül A, Bala O. Adhesion in dentistry and the development of materials used for this purpose. In: Üçtaşlı MB, editor. Current Adhesive Approaches and Clinical Adhesive Applications. 1st ed. Ankara: Türkiye Klinikleri; 2022. p.1-10. Chinelatti MA, Corona SA, Borsatto MC, Ribeiro LF, Rocha RA, Palma-Dibb RG. Analysis of surfaces and adhesive interfaces of enamel and dentin after different treatments. J Mater Sci Mater Med. 2007;18(7):1465-70. Liu M, Xu X, Liu Q, Zhang K, Xin P. Effect of various Er:YAG laser conditioning energies on dentin surface: micromorphological investigation and dentin-resin shear bond strength test. Lasers Med Sci. 2023;38(1):242-50. Zakavi F, Gholizadeh S, Dibazar S, Esmaeili M. A comparison of laser and mechanical surface pretreatment methods on shear bond strength of resin composite to resin-modified glass ionomer. J Dent (Shiraz). 2023;24:103-11. Azimi N, Mohammadi N, Parsaie Z, Fereidouni K. Microleakage and marginal integrity of surface-coated and laser-pretreated class V composite restorations in primary teeth. J Lasers Med Sci. 2023;14:11-7. Tang C, Ahmed MH, Yoshihara K, Peumans M, Van Meerbeek B. Multi-Parameter characterization of HEMA/BPA-free 1- and 2-step universal adhesives bonded to dentin. J Adhes Dent. 2024;26(1):41-52. Tsujimoto A, Fischer NG, Barkmeier WW, Latta MA. Bond durability of two-step HEMA-Free universal adhesive. J Funct Biomater. 2022;13(3):134. Alshehri N, Bin-Shuwaish M. The effects of amalgam contamination and different surface modifications on dentin shear bond strength when using different adhesive protocols. Clin Cosmet Investig Dent. 2021;13:211-21. Harnirattisai C, Senawongse P, Tagami J. Microtensile bond strengths of two adhesive resins to discolored dentin after amalgam removal. J Dent Res. 2007;86(3):232-6. Ghavamnasiri M, Eslami S, Ameri H, Chasteen JE, Majidinia S, Moghadam FV. Effect of amalgam corrosion products in non-discolored dentin on the bond strength of replaced composite resin. J Conserv Dent. 2015;18(1):25-9. Mandava J, Pamidimukkala S, Karumuri S, Ravi R, Borugadda R, Afraaz A. Microtensile bond strength evaluation of composite resin to discolored dentin after amalgam removal. Cureus. 2020;12(4):e7536. Scholtanus JD, Ozcan M, Huysmans MC. Penetration of amalgam constituents into dentine. J Dent. 2009;37(5):366-73. Guven Y, Aktoren O. Shear bond strength and ultrastructural interface analysis of different adhesive systems to Er:YAG laser-prepared dentin. Lasers Med Sci. 2015;30(2):769-78. Zhang Y, Jiang A. The influence of Er:YAG laser treatment on the shear bond strength of enamel and dentin: a systematic review and meta-analysis. Quintessence Int. 2020;51:8-16. Sun G, Chen X, Wei F, Bai T, Zhu S. Effects of Er:YAG, Er,Cr:YSGG, and Nd:YAG laser irradiation and adhesive systems on the immediate and long-term bond strength of dentin: a systematic review and meta-analysis. Lasers Med Sci. 2023;38(1):32-53. Wei D, Nakamoto A, Hiraishi N, Nakane A, Abuna G, Otsuki M, et al. Effect of Er:YAG laser irradiation with additional low energy on resin-dentin bonding and morphology of bonded interface. J Mech Behav Biomed Mater. 2023;140:105692. Usumez A, Sari T, Seseogullari Dirihan R, Esad Guven M, Ahmet SO, Gutknecht N. Effect of acid or laser treatment on degradation of dentin matrix. Lasers Dent Sci. 2022;6:99-105. Kaptan A, Oznurhan F. Effects of Er:YAG and Er,Cr:YSGG laser irradiation and adhesive systems on microtensile bond strength of a self-adhering composite. Lasers Med Sci. 2023;38(1):41-9. Nagarkar S, Theis-Mahon N, Perdigão J. Universal dental adhesives: Current status, laboratory testing, and clinical performance. J Biomed Mater Res B Appl Biomater. 2019;107(6):2121-31. Sezinando A, Perdigão J, Ceballos L. Long-term in vitro adhesion of polyalkenoate-based adhesives to dentin. J Adhes Dent. 2017;19(4):305-16. Brkanović S, Sever EK, Vukelja J, Ivica A, Miletić I, Krmek SJ. Comparison of different universal adhesive systems on dentin bond strength. Materials (Basel). 2023;16(4):1530. Cruz J, Delgado AHS, Félix S, Brito J, Gonçalves L, Polido M. Improving properties of an experimental universal adhesive by adding a multifunctional dendrimer (G-IEMA): Bond strength and nanoleakage evaluation. Polymers. 2022;14(7):1462. Zubrzycki J, Klepka T, Marchewka M, Zubrzycki R. Tests of dental properties of composite materials containing nanohybrid filler. Materials. 2023;16(1):348-64. Karadaglioglu OI, Alagoz LG, Caliskan A, Vaizoglu GA. The effect of different surface roughening systems on the micro-shear bond strength of aged resin composites. Niger J Clin Pract. 2022;25(1):37-43. Ozcan M, Cura C, Brendeke J. Effect of aging conditions on the repair bond strength of a microhybrid and a nanohybrid resin composite. J Adhes Dent. 2010;12(6):451-9. Ouchi H, Takamizawa T, Tsubota K, Tsujimoto A, Imai A, Barkmeier WW, et al. The effects of aluminablasting on bond durability between universal adhesives and tooth substrate. Oper Dent. 2020;45(2):196-208. Additional Declarations No competing interests reported. Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-7115069","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Research Article","associatedPublications":[],"authors":[{"id":492800099,"identity":"8698d6aa-dc23-4bfd-8e1c-0ad49a86facc","order_by":0,"name":"Cem PESKERSOY","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAABCUlEQVRIiWNgGAWjYBADAwhVAaEkSNByBq7FgEgtjG1EaOFv705gLqioM+aXPv7wMe88G7t+BuaDt3kY/uTj0iJx5uwG5hlnDptJ9uUYG/NuS0ue2cCWbM3DYGDZgMtBErkbmHnbDtgYnOFhk+bddjjZ4ACPmTRQC06XGci/BWr5V2djf4b9mTTvnP/J9gf4v+HXIsEL1NLAbGbAw2AmzdtwwM6AAWgdPi0SZ3I3HJ5x7LCxxBkeY8M5x5ITJA6zGVvOMTDGqYW//ezGxwU1dYb9PewPH7ypsbPnb29+eONNhRzeiDkMYzDxMDAkNjCDHYxPAwMDM4zB+IOBwR6/2lEwCkbBKBiJAABm2Urxo1xpfQAAAABJRU5ErkJggg==","orcid":"","institution":"Ege University Faculty of Dentistry","correspondingAuthor":true,"prefix":"","firstName":"Cem","middleName":"","lastName":"PESKERSOY","suffix":""},{"id":492800100,"identity":"4cec3e55-1fdc-4247-8649-118c63669a72","order_by":1,"name":"Hilal BUCEKLER","email":"","orcid":"","institution":"Ege University Faculty of Dentistry","correspondingAuthor":false,"prefix":"","firstName":"Hilal","middleName":"","lastName":"BUCEKLER","suffix":""},{"id":492800101,"identity":"54a09179-d3e5-4c98-b658-65bb402317ee","order_by":2,"name":"Murat TURKUN","email":"","orcid":"","institution":"Ege University Faculty of Dentistry","correspondingAuthor":false,"prefix":"","firstName":"Murat","middleName":"","lastName":"TURKUN","suffix":""}],"badges":[],"createdAt":"2025-07-13 18:53:12","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-7115069/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-7115069/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":87921571,"identity":"e437e333-9f56-44f5-8d00-9ebe105d1405","added_by":"auto","created_at":"2025-07-30 11:51:08","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":169433,"visible":true,"origin":"","legend":"\u003cp\u003eFlow chart of the experimental setup.\u003c/p\u003e","description":"","filename":"image1.tiff.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7115069/v1/de19ea62a72ad74f325624cf.jpg"},{"id":87921572,"identity":"5a296b5c-92dd-4547-8b69-f01b82e592b3","added_by":"auto","created_at":"2025-07-30 11:51:08","extension":"jpeg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":332516,"visible":true,"origin":"","legend":"\u003cp\u003eSurface modification methods used in this study\u003c/p\u003e","description":"","filename":"image2.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-7115069/v1/c3dd20ba83a50dc9e59162c8.jpeg"},{"id":87921106,"identity":"51e6d861-0e30-46c5-8aed-7b5de35e46b6","added_by":"auto","created_at":"2025-07-30 11:43:08","extension":"jpg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":232536,"visible":true,"origin":"","legend":"\u003cp\u003eBox-plot distribution of microshear bond strength test results.\u003c/p\u003e","description":"","filename":"image3.tiff.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7115069/v1/2d24916ac45c0483a501038d.jpg"},{"id":87921103,"identity":"c89550dc-58d9-4fb5-95a2-96b2d4586a7f","added_by":"auto","created_at":"2025-07-30 11:43:08","extension":"jpg","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":114879,"visible":true,"origin":"","legend":"\u003cp\u003eDistribution of failure types in the study\u003c/p\u003e","description":"","filename":"image4.tiff.jpg","url":"https://assets-eu.researchsquare.com/files/rs-7115069/v1/7a6ff29ed7650c0111d9eb9a.jpg"},{"id":87921575,"identity":"7de458ae-1e8f-48f0-9c4c-8140fb793fd5","added_by":"auto","created_at":"2025-07-30 11:51:09","extension":"jpeg","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":775236,"visible":true,"origin":"","legend":"\u003cp\u003eSEM images at 100x and 500x magnification after surface treatment\u003c/p\u003e","description":"","filename":"image5.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-7115069/v1/0da014f607c9ec9bce836565.jpeg"},{"id":89963807,"identity":"a3536335-d6ef-409c-8c08-1c14ff7ede15","added_by":"auto","created_at":"2025-08-27 02:46:51","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":2282023,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-7115069/v1/e53c1933-8db1-452e-87cd-b5124e1da807.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Effect of surface modification methods on dentin-resin bond strength after amalgam contamination: In-vitro study","fulltext":[{"header":"BACKGROUND","content":"\u003cp\u003eFollowing developments and current approaches in dentistry, the clinical use of metal alloy restorative materials such as amalgam is gradually decreasing [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. Important factors such as allergic and autoimmune reactions such as lichen planus caused by amalgam restorations, incompatibility of aesthetic and mechanical properties with dental tissues, mercury content and the related material not being sufficiently biocompatible are the most common reasons for amalgam replacement as stated in Minamata declaration [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. Composite resins have long stood in the breach as a viable alternative to dental amalgams, offering materials that do not require mechanical retention within the cavity and that bond to the tooth surface through micromechanical adhesion. [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e, \u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e]. The hybrid layer formed by the hydrophilic monomers of the adhesive and the collagens exposed on the tooth surfaces (adherent) as a result of different surface roughening processes, especially acid etching, forms the basis of this adhesion process [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. The main factors affecting adhesion are surface energy, contact angle, wettability, the presence of a smear layer and the number and condition of the tubules in the dentin tissue [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e, \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eSurface treatments applied before adhesive bonding to mineralized dental tissues contribute to the adhesion of resin composites to the adherent material. Traditionally, the application of orthophosphoric acid is regarded as the gold standard among chemical surface conditioning methods [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. Although the duration of the pickling process varies according to the case and material, prolonged pickling of the enamel creates a deep roughened area, and the adhesive cannot spread over this roughened area. This leads to the formation of dead spaces and may result in discolouration and secondary caries formation at the edge of the restoration [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. Mechanical surface preparation methods such as diamond burs, sandblasting and air abrasion can produce micro- and macro roughening of the tooth surface with aluminum oxide particles or diamond particles pushed at high speed [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. Dental lasers, which have recently become widespread, are another method used for surface modification. Er:YAG and Er,Cr:YSGG laser systems vary in the depth of roughness they create on the surface according to different wavelengths and pulse numbers [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]. Laser irradiation, which is applied to the tooth surface causes the water content within the hydroxyapatite matrix evaporate and dehydration [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. Unlike enamel, dentin has a tubular structure and contains moisture, which makes adhesion to dentin more challenging in terms of “exposing the peritubular and intertubular dentin without demineralizing” and “avoiding smear layer formation” [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eCurrent adhesive systems aim to strengthen adhesion to dentin, and for this purpose, the contents of the materials are constantly being improved. The 8th-generation universal adhesive, which shortens the clinical study time, is claimed to strengthen adhesion. Some of the monomers in the content of the 8th generation universal adhesives include 4 methacryloxyethyl trimelliate anhydrides (4-META), methacryloxyethyl phenyl hydrogen phosphate (MEP-P), methacrylolsipropyl dihydrogen phosphate (MMP), methacryoloxyethyl dihydrogen phosphate (MEP), 10-methacryloyloxy decyl phosphate (10-MDP), 2-hydroxyethyl methacrylate (HEMA), silane, methacryloloxyalkyl acid phosphate (MAC-10), vitre bond copolymer, glycerol dimethacrylate ester (GPDM), and dipentaerythrolpentaacrylol dihydrogen phosphate (PENTA-P) were developed to increase adhesion in secondary treatments such as absence of sound dentin, restoration repairs and renewals [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. HEMA monomers are prone to hydrolysis and absorption because of their hydrophilic structure, and HEMA and bisphenol A (BPA) monomers can cause cytotoxic and allergic reactions [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e, \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eThe aim of this study was to restore the affected dentin tissue after the removal of amalgam restorations using different surface modification methods and different universal adhesive systems and to compare the bond strengths. The first hypothesis (h1) of the study is that there will be a difference between the bond strengths of restorations made via different surface modification methods, and the second hypothesis (h2) is that there will be a difference between the bond strengths of restorations made via different universal adhesive systems.\u003c/p\u003e"},{"header":"METHODS","content":"\u003cp\u003eIn this study, 27 caries-free human molars without surface fractures or microcracks were used. Local protocols reviewed and approved by the Ege University Ethics Committee (reg no: 24-7T/52) were followed and informed consent formed was secured from all participants. The post-extraction residues on the surfaces of the teeth were cleaned mechanically, disinfected with 5% sodium hypochlorite solution for 24 hours and then stored in 0.025% thymol solution at room temperature until the completion of the test and measurement stages. The materials used in this study are shown in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e, the experimental flow chart of the samples is shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e.\u003c/p\u003e\u003cdiv class=\"gridtable\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eMaterials used in the study and their contents\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"5\"\u003e\u003c/colgroup\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eMaterial\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eManufacturer\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eClassification\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eLOT No\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u003cp\u003eComposition\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eSolare Universal Bond\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eGC, \u003c/p\u003e\u003cp\u003eTokyo, \u003c/p\u003e\u003cp\u003eJapan\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eUniversal Adhesive\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e2309044\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e4-META, silanated colloidal silica, UDMA, TEGDMA, 10-MDP, acetone (25–50%), water (\u0026gt; 20%), initiators\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eScotchbond Universal Plus\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e3M Oral Care, \u003c/p\u003e\u003cp\u003eSt. Paul, \u003c/p\u003e\u003cp\u003eMN, USA\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eUniversal Adhesive\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e10517802\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eBis-GMA, 10-MDP, 2-HEMA, Vitrebond copolymer, ethanol, water, initiators, fillers\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGluma Bond Universal\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eKulzer, \u003c/p\u003e\u003cp\u003eHanau, \u003c/p\u003e\u003cp\u003eGermany\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eUniversal Adhesive\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eNO10068\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e10-MDP, 4-META, Bis-GMA, 4-ethyl dimethyl aminobenzoate, cetylamine hydrofluoride, initiator, acetone (25–50%), water\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eG-aenial A'CHORD\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eGC,\u003c/p\u003e\u003cp\u003eTokyo,\u003c/p\u003e\u003cp\u003eJapan\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eNano Hybrid Resin Composite\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e2007021\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eBis-MEPP, filler load: 82% by weight: Glass-filler (300 nm barium glass) 16 nm (fumed silica), organic filler (300 nm barium glass; 16 nm fumed silica)\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eFiltek Z550\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003e3M/ESPE, \u003c/p\u003e\u003cp\u003eSt. Paul, \u003c/p\u003e\u003cp\u003eMN, USA\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eNano Hybrid Resin Composite\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003e10297071\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eBis-GMA, Bis-EMA, PEGDMA, TEGDMA, UDMA, surface-modified zirconia/silica fillers, nonagglomerated / nonaggregated surface modified silica particles.\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eCharisma Topaz\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eKulzer, \u003c/p\u003e\u003cp\u003eHanau, \u003c/p\u003e\u003cp\u003eGermany\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003eNano-Hybrid Resin Composite\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u003cp\u003eN010220\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003eBarium aluminum fuoride glass (0.02-2 µm), TEGDMA 5 vol% pyrogenic, UDMA, TCD-DI-HEA silicon dioxide 0.02–0.07 µm,\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eCondak 37\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eFGM,\u003c/p\u003e\u003cp\u003eJoinville,\u003c/p\u003e\u003cp\u003eSC, Brazil\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c3\"\u003e\u003cp\u003e37% phosphoric acid\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e37% phosphoric acid, thickener, pigment and deionized water\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/table\u003e\u003c/div\u003e\u003cp\u003e*Information provided by the manufacturers. 4-META: 4-methacryloxyethyl trimelliate anhydride; UDMA: urethane dimethacrylate; TEGDMA: triethyleneglycol dimethacrylate; 10-MDP: 10-methacryloyloxydecyl dihydrogen phosphate; Bis-GMA: bisphenol A glycidyl methacrylate; 2-HEMA: 2-hydroxyethyl methacrylate; Bis-MPEPP: 2, 2′-bis(4-methacryloxy polyethoxyphenyl) propane; BIS-EMA: ethoxylated bisphenol A glycol dimethacrylate; PEGDMA: polyethylene glycol dimethacrylate; TCD-DI-HEA: Bis-(acryloyloxymethyl) tricyclodecane.\u003c/p\u003e\u003cp\u003e\u003cem\u003ePreparation of Samples\u003c/em\u003e\u003c/p\u003e\u003cp\u003eThe crowns of all teeth were removed from the occlusal 1/3 in the horizontal direction with the help of a 4 mm thick isomet saw (Buehler Ltd., Lake. Bluff, IL, USA) in the horizontal direction to reach large dentin sections in the coronal region of the teeth where the composites would be applied. The crown sections were fixed in cylindrical Teflon molds with an inner diameter of 14 mm, an outer diameter of 22 mm and a height of 14 mm, with the enamel and dentin surfaces above and parallel to the ground plane, leaving a gap of at least 2 mm from the incisal surface, with fast-setting repair acrylic. Amalgam restorations were applied to the samples without a 2 mm cavity wall remaining on the occlusal surfaces of the molds and with a dentin surface only at the base. After the Teflon molds were removed, the samples were subjected to natural aging in artificial saliva solution for 5 years. The artificial saliva used was prepared to simulate the composition of Fusayama-Meyer’s artificial saliva solution. The formulation consisted of distilled water (1L), KCl (0.4 g/L), NaCl (0.4 g/L), CaCl₂·2H₂O (0.906 g/L), NaH₂PO₄·2H₂O (0.690 g/L), Na₂S·9H₂O (0.005 g/L), and urea (1.0 g/L), with the pH adjusted to 6.5. The solution was renewed weekly. After aging, the amalgams were removed from the tooth surfaces with hand tools (excavators) and placed in an oven at 37°C for 24 hours between all steps to prevent dehydration.\u003c/p\u003e\u003cp\u003e\u003cem\u003eSeparation of samples into groups\u003c/em\u003e\u003c/p\u003e\u003cp\u003eThe grouping of the samples is schematized in Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e. The prepared samples were divided into 4 groups according to the surface modification / roughening processes to be applied:\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eGroup 1\u003c/strong\u003e\u003c/p\u003e\u003cp\u003eAcid etching; 37% ortho-phosphoric acid (Condak 37, FGM, Joinville, SC, Brazil) application,\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eGroup 2\u003c/strong\u003e\u003c/p\u003e\u003cp\u003eAir-abrasion (Air-prophy unit, Stardent Equip. Co. Ltd., Gongfu, China) sandblasting with aluminium oxide fragments,\u003c/p\u003e\u003cp\u003e\u003cb\u003eGroup 3\u003c/b\u003e: Er:YAG dental laser (LightWalker AT, Fotona, Ljubljana, Slovenia) device roughening in non-contact mode,\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eGroup 4\u003c/strong\u003e\u003c/p\u003e\u003cp\u003eControl group; group without surface modification.\u003c/p\u003e\u003cp\u003e\u003cem\u003eSurface Preparation\u003c/em\u003e\u003c/p\u003e\u003cp\u003eFor the group 1 samples, the dentin tissue was etched with 37% orthophosphoric acid for 15 s, washed with the air‒water spray of the dental unit for the same amount of time and dried with light compressed air. In Group 2, the tooth surfaces were roughened via standard parameters (particle size: 50 µm, distance: 10 mm, angle: 90\u003cspan class=\"InlineEquation\"\u003e\u003cspan class=\"mathinline\"\u003e\\(\\:^\\circ\\:\\)\u003c/span\u003e\u003c/span\u003e and pressure 70 ± 2 psi) with abrasive powder containing aluminum oxide. During sandblasting, other areas on the same sample were covered with dental transparent silicone to prevent particle scattering, and sandblasting was performed in this way. After sandblasting, the samples were thoroughly washed for 10 s via a dental unit air‒water syringe and dried with light compressed air. In Group 3, dentin tissue was modificated with an Er:YAG laser (LightWalker AT, Fotona Medical Lasers, Ljubljana, Slovenia) with a wavelength of 2.94 mm, a frequency of 20 Hz and a pulse duration of 100 ms (medium short pulse) in non-contact \"etching mode\" using fixed parameters (power: 4 W, energy: 200 mJ) at a distance of 7 mm from the dentin surface under water cooling (50 ml/min). The selected parameters (4 W power, 200 mJ energy, 20 Hz frequency, 100 µs pulse duration) were based on previous studies demonstrating their effectiveness in optimizing surface roughness and enhancing micromechanical interlocking, which plays a crucial role in the bond strength between aged composite resin and the repair material.\u003c/p\u003e\u003cp\u003e\u003cem\u003eConstruction of Composite Blocks\u003c/em\u003e\u003c/p\u003e\u003cp\u003eThe samples were randomly divided into 3 subgroups according to the adhesive system and compatible resin composite material (n = 9):\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eSubgroup GC\u003c/strong\u003e\u003c/p\u003e\u003cp\u003eSolare Universal Bond (7th generation adhesive) + G-aenial A'CHORD (nanohybrid composite), (GC Dental Corp, Tokyo, Japan),\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eSubgroup 3M\u003c/strong\u003e\u003c/p\u003e\u003cp\u003eScotchbond Universal Plus (8th generation adhesive) + Filtek Z550 (nanohybrid composite) (3M ESPE, St. Paul, MN, USA).\u003c/p\u003e\u003cp\u003e\u003cspan type=\"BoldItalicUnderline\" class=\"BoldItalicUnderline\" name=\"Emphasis\"\u003eSubgroup HK\u003c/span\u003e Gluma Bond Universal (7th generation adhesive) + Charisma Topaz (nanohybrid composite) (Heraus Kulzer GmbH, Hanau, Germany),\u003c/p\u003e\u003cp\u003eAfter surface preparation, resin composite blocks 2 mm in diameter and 5 mm in height were prepared using a universal jig (Ultradent, South Jordan, UT, USA). For this purpose, universal adhesives and composite resins were applied to each group according to the manufacturer's instructions. In subgroup GC, the adhesive Solare Universal Bond (GC, Tokyo, Japan) was applied to the dentin surface with a rubbing motion for 10 s, dried slightly with air spray and polymerized with an LED light device (Bluephase 20i; Ivoclar Vivadent, Schaan, Liechtenstein) with a light power of 1200 mW/cm\u003csup\u003e2\u003c/sup\u003e for 20 s. Then, the G-aenial A'CHORD (GC, Tokyo, Japan) nanohybrid composite was placed in the jig in 2 mm layers and polymerized for 20 s each time. In subgroup 3M, Scotchbond Universal Plus (3M ESPE, St. Paul, MN, USA) was applied to the dentin surface with a disposable applicator for 20 s with a vigorous rubbing motion. Then, the adhesive was spread on the tooth surface with light pressure for at least 5 s and polymerized for 10 s with an air spray until the adhesive layer formed a non-moving glossy film. Filtek Z550 (3M ESPE, St. Paul, MN, USA) nanohybrid composite was then applied in 2 mm layers into the jig and polymerized for 20 s each time. In subgroup HK, Gluma Bond Universal (Heraus Kulzer GmbH, Hanau, Germany) was applied to the cavity with a soft brush and gently rubbed for 20 s, then air dried until no fluid movement was detected and polymerized for 10 s. Charisma Topaz (Kulzer, Hanau, Germany) nanohybrid composite was subsequently placed in the jig in 2-mm layers and polymerized for 20 s each time.\u003c/p\u003e\u003cp\u003eThe samples were inspected with a light microscope (S8 APO, Leica Microsystems GmbH, Wetzlar, Germany) at 10x magnification to check for any layering defects. During this examination, any defects, abrasions, visible air pockets or bonding problems on the composite block and tooth surfaces were carefully reviewed, and specimens with problems were excluded from the study.\u003c/p\u003e\u003cp\u003e\u003cem\u003eMicroshear Bond Strength (µSBS) Test\u003c/em\u003e\u003c/p\u003e\u003cp\u003eThe composite blocks were subjected to shear tests with a universal testing machine (AG-50kNG, Schimadzu, Tokyo, Japan) using a (thick knife-edge type blade) with specified test parameters (tip speed: 1.0 mm/min, maximum load: 50 kg/cm\u003csup\u003e2\u003c/sup\u003e). The failure loads (MPa) and the maximum applied load (N) were recorded. The fracture types (adhesive, cohesive, mixed, composite fracture) were recorded as a result of the bond strength test by examining the fracture types formed on the sample surfaces as a result of the fracture test under a light microscope at 2.5X and 10X magnifications.\u003c/p\u003e\u003cp\u003e\u003cem\u003eScanning Electron Microscopy Images and Determination of Fracture Types\u003c/em\u003e\u003c/p\u003e\u003cp\u003eAfter the crushing test, the changes on the sample surfaces and the amalgam residues remaining on the surfaces were examined by scanning electron microscopy (SEM) (Apreo S SEM, Thermo Scientific, The Netherlands) at a low vacuum of 150 millitorrs, a filament voltage of 10 kV and magnifications of 1000, 5000 and 10,000.\u003c/p\u003e\u003ch2\u003eStatistical Analysis\u003c/h2\u003e\u003cp\u003eAll the data obtained were transferred to statistical analysis software (SPSS, vers. 27.0 IBM, Chicago, IL, USA), the data obtained from each test method were first examined for homogeneous distribution using the Kolmogorov-Smirnof test and the minimum, median, maximum and mean values of the samples were determined. The alpha value was calculated as \u003cem\u003ep = 0.05\u003c/em\u003e. The analysis indicated that the laser group (p = 0.200), acid etching group (p = 0.191), control group (p = 0.200), and sandblasting group (p = 0.121) exhibited a homogeneous distribution, allowing the application of one-way ANOVA with post hoc Tukey test to all groups.\u003c/p\u003e"},{"header":"RESULTS","content":"\u003cp\u003e\u003cem\u003eMicroshear Bond Strength Results\u003c/em\u003e\u003c/p\u003e\u003cp\u003eTable\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e shows the means and standard deviations of the strength variables of the groups. The \u0026micro;SBS values of the surface modifications and adhesive systems used are shown in Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003e. When all the groups were evaluated in the present study, the highest mean bond strength was measured in the Er:YAG laser group (30.88\u0026thinsp;\u0026plusmn;\u0026thinsp;5.19 MPa), followed by the acid etching (26.50\u0026thinsp;\u0026plusmn;\u0026thinsp;3.77 MPa), control (20.68\u0026thinsp;\u0026plusmn;\u0026thinsp;4.75 MPa) and sandblast groups (11.51\u0026thinsp;\u0026plusmn;\u0026thinsp;4.47 MPa) (\u003cem\u003ep\u0026thinsp;=\u0026thinsp;0.000\u003c/em\u003e). According to the bond strength test results of the composite resins after surface modification, a significant difference was found between all the groups \u003cem\u003e(p\u0026thinsp;=\u0026thinsp;0.000\u003c/em\u003e). While there was no significant difference among the GC, 3M and HK subgroups in the sandblasted samples (\u003cem\u003ep\u0026thinsp;\u0026gt;\u0026thinsp;0.05\u003c/em\u003e), the lowest bond strength among all the samples was measured in the sandblasted\u0026thinsp;+\u0026thinsp;HK subgroup (3.61 MPa) (Table\u0026nbsp;\u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). Among the 3M samples, there was no significant difference between the sandblasting group and the control group (\u003cem\u003ep\u0026thinsp;=\u0026thinsp;0.519\u003c/em\u003e), but lower bond strength results were obtained, unlike those of the other modification methods, acid etching and laser groups (\u003cem\u003ep\u0026thinsp;=\u0026thinsp;0.000\u003c/em\u003e).\u003c/p\u003e\u003cp\u003e\u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab2\" border=\"1\"\u003e\u003ccaption language=\"En\"\u003e\u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e\u003cdiv class=\"CaptionContent\"\u003e\u003cp\u003eBond strength values obtained from the study and significant differences\u003c/p\u003e\u003c/div\u003e\u003c/caption\u003e\u003ccolgroup cols=\"7\"\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e\u003cdiv align=\"left\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e\u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e\u003cthead\u003e\u003ctr\u003e\u003cth align=\"left\" colname=\"c1\"\u003e\u003cp\u003eComposites\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c2\"\u003e\u003cp\u003eSurface Modification\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c3\"\u003e\u003cp\u003eMinimum\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c4\"\u003e\u003cp\u003eMaximum\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c5\"\u003e\u003cp\u003eMean\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c6\"\u003e\u003cp\u003eSD\u003c/p\u003e\u003c/th\u003e\u003cth align=\"left\" colname=\"c7\"\u003e\u003cp\u003e\u003cem\u003eP\u003c/em\u003e\u003c/p\u003e\u003c/th\u003e\u003c/tr\u003e\u003c/thead\u003e\u003ctbody\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eGC\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eAcid etch\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e21.58\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e31.12\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e27.64\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e2.90\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\" morerows=\"3\" rowspan=\"4\"\u003e\u003cp\u003e0.001\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eM. Blasting\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e\u003cspan type=\"Underline\" class=\"Underline\" name=\"Emphasis\"\u003e5.94\u003c/span\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e20.48\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e10.79\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e4.08\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eEr:YAG Laser\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e25.48\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e\u003cb\u003e37.18\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e31.14\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e3.83\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eControl\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e21.54\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e34.62\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e25.54\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e4.45\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003e3M\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eAcid etch\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e22.17\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e32.99\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e28.93\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e3.45\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\" morerows=\"3\" rowspan=\"4\"\u003e\u003cp\u003e0.001\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eM. Blasting\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e\u003cspan type=\"Underline\" class=\"Underline\" name=\"Emphasis\"\u003e10.09\u003c/span\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e19.72\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e14.13\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e3.26\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eEr:YAG Laser\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e29.98\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e\u003cb\u003e39.91\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e34.86\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e3.36\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eControl\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e14.38\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e22.01\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e18.12\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e2.37\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u003cp\u003eHK\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eAcid etch\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e19.51\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e27.45\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e22.93\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e2.30\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c7\" morerows=\"3\" rowspan=\"4\"\u003e\u003cp\u003e0.001\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eM. Blasting\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e\u003cspan type=\"Underline\" class=\"Underline\" name=\"Emphasis\"\u003e3.61\u003c/span\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e18.28\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e9.61\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e5.27\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eEr:YAG Laser\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e20.15\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e\u003cb\u003e33.14\u003c/b\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e26.62\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e5.16\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003ctr\u003e\u003ctd align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/td\u003e\u003ctd align=\"left\" colname=\"c2\"\u003e\u003cp\u003eControl\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e\u003cp\u003e12.35\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e\u003cp\u003e23.87\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"left\" colname=\"c5\"\u003e\u003cp\u003e18.38\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e\u003c/td\u003e\u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e\u003cp\u003e3.31\u003c/p\u003e\u003c/td\u003e\u003c/tr\u003e\u003c/tbody\u003e\u003c/colgroup\u003e\u003ctfoot\u003e\u003ctr\u003e\u003ctd colspan=\"7\"\u003e* The mean shear bond strengths with different superscripts for the same material shows significant differences\u003c/td\u003e\u003c/tr\u003e\u003c/tfoot\u003e\u003c/table\u003e\u003c/div\u003e\u003c/p\u003e\u003cp\u003e** SD: Standard deviation.\u003c/p\u003e\u003cp\u003e*** Minimum (underlined) and maximum (bold\u0026thinsp;+\u0026thinsp;italic) shear bond values were emphasized in the table.\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003eWhile there was a significant difference between the laser and sandblasting (\u003cem\u003ep\u0026thinsp;=\u0026thinsp;0.000\u003c/em\u003e) and control (\u003cem\u003ep\u0026thinsp;=\u0026thinsp;0.038\u003c/em\u003e) groups, there was no significant difference between the laser and acid groups (\u003cem\u003ep\u0026thinsp;=\u0026thinsp;0.708\u003c/em\u003e). Similarly, in the 3M subgroup, there was no difference between the laser and acid groups (\u003cem\u003ep\u0026thinsp;=\u0026thinsp;0.635\u003c/em\u003e), and more successful results were observed than in the sandblasting (\u003cem\u003ep\u0026thinsp;=\u0026thinsp;0.000\u003c/em\u003e) and control (\u003cem\u003ep\u0026thinsp;=\u0026thinsp;0.001\u003c/em\u003e) groups. There was no significant difference between the GC and 3M subgroups or between the GC and HK subgroups for the samples modified with the dental laser surface, but the 3M subgroup presented better bond strength than did the HK subgroup (\u003cem\u003ep\u0026thinsp;=\u0026thinsp;0.001\u003c/em\u003e). Among the laser-treated samples, the highest bond strength was observed in the 3M subgroup (39.91 MPa). When the samples in the GC and HK groups were evaluated within themselves, a significant difference (\u003cem\u003ep\u0026thinsp;=\u0026thinsp;0.000\u003c/em\u003e) was observed only between the acid etching and sandblasting groups. Among all the samples etched with acid, a significant difference was found only between 3M and HK subgroups (\u003cem\u003ep\u0026thinsp;=\u0026thinsp;0,045\u003c/em\u003e). The highest bond strength in the acid-etched samples was found in the 3M subgroup (32.99 MPa).\u003c/p\u003e\u003cp\u003e\u003cem\u003eClassification of Failure Types\u003c/em\u003e\u003c/p\u003e\u003cp\u003eFollowing the \u0026micro;SBS test, the failure types observed in each group were visualized with light microscopy (DM 500 RH, Leica Camera AG, Wetzlar Germany). The most common failure type observed in this study was adhesive fracture (54.62%), and there was a statistically significant difference between surface modifications (\u003cem\u003ep\u0026thinsp;\u0026lt;\u0026thinsp;0.05).\u003c/em\u003e Unlike the other groups, cohesive and composite fracture types were not observed in the control group, whereas adhesive fracture was the most observed failure in the acid and control groups. While there was no statistically significant difference between the adhesive subgroups (\u003cem\u003ep\u0026thinsp;\u0026gt;\u0026thinsp;0.05)\u003c/em\u003e, surface modification methods were found to have an effect on determining fracture type. (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003e)\u003c/p\u003e\u003cp\u003e\u003c/p\u003e\u003cp\u003e\u003cem\u003eScanning Electron Microscopy Evaluation\u003c/em\u003e\u003c/p\u003e\u003cp\u003eAfter the removal of the amalgam restorations, partial traces of amalgam contamination and particle residues were observed on the dentin surface of all the samples (Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003e). After surface modification, amalgam contamination was found to be the highest, especially in the sandblasting and control group. Compared with those on the other surface modification methods, fewer smear layer was observed on the dentin surfaces modified with the Er:YAG laser. Besides, the deformation caused by the Er:YAG laser in the dentin tissue due to high heat and ablation is also observed. Compared with those of the other groups, the sandblasted samples presented more irregular peritubular dentin on the dentin surface, and the specific shape created by the roughening process and aluminium oxide particles are also observed. For the control group, the smear layer covered the entire dentin surface and therefore the dentinal tubules could almost not be observed.\u003c/p\u003e"},{"header":"DISCUSSION","content":"\u003cp\u003eIn this study, sandblasting, acid and laser surface modification methods were applied to the affected dentin tissue after amalgam filling removal in aged teeth and restored with different universal adhesive systems with different nanohybrid composites, and the bond strengths were compared. Dentin tissue without surface modification was used as a control group. Based on the results of this study, dentin surface treatments generally affect the bond strength. In particular, the bond strength was found to be significantly higher in the laser-treated samples; therefore, hypothesis h1 was accepted. In addition, the secondary hypothesis that there would be a difference in bond strength between different universal adhesive systems was also accepted.\u003c/p\u003e\u003cp\u003eThe colouration of dental tissues caused by the corrosive products of amalgam and the presence of these products negatively affect adhesive bonding. Nojoud Alshehri \u003cem\u003eet al.\u003c/em\u003e reported that, compared with that of unaffected dentin, the adhesion of bulk-fill composite resin to amalgam-affected dentin yielded negative results [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e]. Harnirattisai \u003cem\u003eet al.\u003c/em\u003e and Ghavamnasiri \u003cem\u003eet al.\u003c/em\u003e reported similar results indicating that the most likely explanation is the formation of a sclerotic dentin layer and the restriction of the formation of resin tags by blockage of dentin tubules with corrosive products such as Sn, Zn and Cu in the amalgam structure [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e, \u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]. These corrosive products have been shown to cause the precipitation of plasma proteins into the dentin fluid, reduce dentin permeability, and increase the difficulty of removing the smear layer of amalgam-affected dentin [\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e, \u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]. According to the results of these studies, clinical procedures should be determined by considering the different structures of the affected dentin after amalgam removal. SEM revealed that a significant number of particles remained in the dentinal tubules after amalgam removal in each group, and these particles negatively affected the bond strength. In this respect, our results are consistent with studies in the literature.\u003c/p\u003e\u003cp\u003eDifferent surface modification procedures can be applied to dentin tissue to strengthen adhesion especially acid etching. Adhesion of the composite resin to the dentin surface is achieved by micromechanical locking with resin tags in the gaps on the dentin surface after acid application [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. By increasing the surface area with sandblasting, adhesion to the dentin surface is strengthened by increasing the surface energy. However, there are also studies showing the opposite results in the literature. The surface properties abraded by sandblasting differ chemically from those of acid-etched surfaces, and some studies have shown that aluminum oxide particles remain in the dentin tubules and are thought to clog the tubules [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e, \u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e]. In this study, the bond strength obtained from the sandblasted samples was the lowest, and the most likely reason for this was that the sandblasting process with aluminum oxide particles negatively affected the tubule structure and the stability of the collagens.\u003c/p\u003e\u003cp\u003eIn this study, an Er:YAG laser was used as another surface roughening method. Although many studies in the literature have investigated the bond strengths to dental hard tissues via the Er:YAG laser, the results obtained from these studies are contradictory and even controversial\u003csup\u003e2\u003c/sup\u003e [\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e, \u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e]. Some researchers claim that the dental laser increases adhesion because it expands the bonding area available on dentin surfaces, vaporizes the lymph fluid in the dentinal tubules in a controlled manner, and creates a clean dentin surface free of a smear layer [\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e, \u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e]. In addition, studies have suggested that adhesion is lower because more collagen destruction results from acid etching than from the use of a dental laser [\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e]. In recent studies, Er:YAG laser application has been reported to change the dentin surface and thus the bonding mechanism of adhesives to dentin, and a smooth dentin surface can increase the bond strength between dentin and resin\u003csup\u003e1\u003c/sup\u003e [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e, \u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e]. The results of the present study revealed that the Er:YAG laser applied in surface modification mode left fewer smear layers in the dentin tissue; thus, the \"resin tags\" formed by the adhesive systems in the dentin tubules were greater in volume. In this respect, our results support current studies.\u003c/p\u003e\u003cp\u003eThe most recent group of adhesives, Generation 8 universal adhesives, work with a similar mechanism to traditional one-step self-etch adhesives, but their activity is modified by the pH of their acidic monomers. Unlike universal adhesives, they contain carboxylate and/or phosphate functional monomers. Among these monomers, 10-MDP ionically binds to dentin by forming dissolution-resistant calcium salts on hydroxyapatite in the form of nanolayers\u003csup\u003e27)\u003c/sup\u003e. In addition, 10-MDP is an important monomer that is the most resistant to hydrolytic degradation among other functional monomers, strengthens chemical bonding and can also chemically bond with zirconium oxide [\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e]. According to long-term studies, when universal adhesives are applied in self-etch mode, more stable chemical bonding is achieved when the samples are aged depending on the monomers they contain, such as 10-MDP [\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e, \u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e]. Hydrophilic monomers such as HEMA in adhesives are known to reduce adhesion by increasing the susceptibility of the bonding interface to hydrolytic and enzymatic degradation\u003csup\u003e29)\u003c/sup\u003e. Therefore, monomers such as hydrophilic HEMA and allergenic BPA have been removed from new universal adhesives. In this study, the BPA-free adhesive was found to provide better bond strength than the other 8th generation adhesives did, and this result is consistent with studies in the literature [\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e].\u003c/p\u003e\u003cp\u003eTang. \u003cem\u003eet al.\u003c/em\u003e reported that the superior bond strength results of BPA-free adhesives in their bonding strength tests could be attributed to the synthesis of Bis-GMA alternatives, which exhibit equivalent or even superior crosslinking potential and mechanical properties [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. Found that while BPA-free adhesives demonstrated similar bond strength to other adhesives in their study, they formed more resin tags, reduced polymerization shrinkage, and enhanced bond quality by increasing conversion rates. These improvements were associated with the inclusion of the G-IEMA monomer, which features a three-dimensional structure composed of eight polymerizable methacrylate groups. In the current study, the manufacturer of the Scotchbond\u0026trade; Universal Plus BPA-free adhesive claims that it contains HEMA (2-hydroxyethyl methacrylate) and Bis-GMA (bisphenol A glycidyl methacrylate) dimethacrylate resins, but states that Bis-GMA is BPA-free, consisting of crosslinkable and radiopaque monomers, with no BPA in the formulation. While detailed composition information has not been disclosed, this enhanced monomer structure could be linked to the high bond strength results observed in this study. Following the removal of amalgam restorations, metal ions such as tin may accumulate within the dentinal tubules, leading to their occlusion, reduced permeability, and consequently diminished resin tag formation [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]. In the present study, BPA-free adhesives demonstrated superior bonding performance on these modified surfaces, which may be attributed to enhanced tubular infiltration.\u003c/p\u003e\u003cp\u003eComposite resins have different mechanical properties, such as compressive strength, modulus of elasticity, and microhardness, depending on the number of particles, size and type of filler they contain [\u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e]. Many materials, such as micro- and nanoparticle composites and hybrid composites, have been developed because classical macrofil composites are not polished well, undergo rapid colour changes, and are not resistant to occlusal wear\u003csup\u003e6)\u003c/sup\u003e. Nanohybrid composites meet the aesthetic expectations of patients while increasing the surface properties of restorations. In addition to their good polishability and good aesthetic properties, they are durable materials with low polymerization shrinkage [\u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e]. \u0026Ouml;zcan \u003cem\u003eet al.\u003c/em\u003e compared the bond strengths of microhybrid and nanohybrid resin composites and reported that they had similar bond strengths [\u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e]\u003c/p\u003e\u003cp\u003eBrkanovi\u0026acute;c \u003cem\u003eet al.\u003c/em\u003e measured the bond strength of universal adhesives to dentin and reported a significant difference between the Scotchbond Universal Plus (3M ESPE) and G2-Bond Universal (GC) groups. In this study, the bonds in the GC subgroup were greater than those in the 3M subgroup without surface treatment [\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e]. The greater results of the 3M subgroup in samples with surface modifications should be taken into consideration in clinical use. Ouchi \u003cem\u003eet al.\u003c/em\u003e examined the bond strength of universal adhesives after sandblasting and reported a lower bond strength on sandblasted dentin surfaces [\u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e]. Similar to the results of this study, the G-Premio Bond (GC) group presented lower results than did the Scotchbond Universal (3M) subgroup. Considering all the results, the 3M subgroup is the most effective method of laser surface modification of amalgam-affected dentin, providing high bond strength to dentin compared with other adhesives.\u003c/p\u003e"},{"header":"CONCLUSION","content":"\u003cp\u003eComposite resins are the preferred restoration material in cases such as the presence of secondary caries, aesthetic reasons, fractures or edge incompatibilities where amalgam must be removed. One of the most important criteria for the success of composite restorations is ensuring adhesion. Amalgam-affected dentin is sclerosed and contains amalgam residues. Various surface roughening procedures, especially laser application, strengthen the adhesion of the composite to the dentin tissue. However, sandblasting, which smooths the surface owing to its abrasive nature, has a decreasing effect on the bond strength. On the other hand, HEMA and BPA-free 8th generation adhesives were successful in terms of bond strength and penetration into dentin. HEMA- and BPA-free generation 8 adhesives with surface modification methods are recommended for these cases, for which there is no recommended procedure in clinical practice within the limits of the study.\u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cdiv class=\"DefinitionList\"\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003e\u0026bull; 10-MDP\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003e10-methacryloyloxy decylphosphate\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003e\u0026bull; 4-META\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003e4-methacryloxyethyl trimellitate anhydride\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003e\u0026bull; BPA\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eBisphenol A\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003e\u0026bull; Er\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eYAG:Erbium-doped yttrium aluminum garnet\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003e\u0026bull; G-IEMA\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eGlycerol-based isosorbide ether methacrylate\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003e\u0026bull; GPDM\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eGlycerol phosphate dimethacrylate\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003e\u0026bull; HEMA\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003e2-hydroxyethyl methacrylate\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003e\u0026bull; MAC-10\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eMethacryloloxyalkyl acid phosphate\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003e\u0026bull; MEP\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eMethacryloxyethyl dihydrogen phosphate\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003e\u0026bull; MEP-P\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eMethacryloxyethyl phenyl hydrogen phosphate\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003e\u0026bull; MMP\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eMethacrylolsipropyl dihydrogen phosphate\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003e\u0026bull; \u0026micro;SBS\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eMicroshear bond strength\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003e\u0026bull; PENTA-P\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eDipentaerythritol pentaacrylate phosphate\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003cdiv class=\"DefinitionListEntry\"\u003e\u003cdiv class=\"Term\"\u003e\u0026bull; SEM\u003c/div\u003e\u003cdiv class=\"Description\"\u003e\u003cp\u003eScanning electron microscopy\u003c/p\u003e\u003c/div\u003e\u003c/div\u003e\u003c/div\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eEthics approval and consent to participate:\u003c/strong\u003e This study was approved by the Ethics Committee of Ege University Faculty of Dentistry (Approval No: 24-7T/52). All procedures involving extracted human teeth were performed in accordance with the ethical standards of the institutional and/or national research committee. Informed consent to participate was obtained from all the participants.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication:\u003c/strong\u003e Not applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials:\u003c/strong\u003e The datasets generated and/or analysed during the current study are available from the corresponding author on reasonable request.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting interests:\u003c/strong\u003e The authors declare that they have no competing interests.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding:\u003c/strong\u003e This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u0026rsquo; contributions:\u003c/strong\u003e HB contributed to sample preparation, surface modification procedures. CP contributed to the study design, data interpretation, statistical analysis and manuscript supervision. MT contributed to the methodological planning, result interpretation, and final manuscript revision. All authors read and approved the final manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgements:\u0026nbsp;\u003c/strong\u003eNot applicable.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u0026rsquo; information:\u003c/strong\u003e HB is a PhD student and research assistant at the Department of Restorative Dentistry, Ege University, Turkey. CP is an Associate Professor in the same department, specializing in adhesive and restorative dentistry. MT is a full Professor of Restorative Dentistry with extensive experience in dental materials research.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eMackey TK, Contreras JT, Liang BA. The Minamata convention on mercury: Attempting to address the global controversy of dental amalgam use and mercury waste disposal. Sci Total Environ. 2014;472:125-9.\u003c/li\u003e\n\u003cli\u003eTibau A, Grube B. Dental amalgam and the minamata convention on mercury treaty: Make mercury history for all. J Oral Dent Health. 2023;7(3):227-41.\u003c/li\u003e\n\u003cli\u003eAntoniadou M, Varzakas T, Tzoutzas I. Circular economy in conjunction with treatment methodologies in the biomedical and dental waste sectors. Circ Econ Sustain. 2021;1(2):563-92.\u003c/li\u003e\n\u003cli\u003e\u0026Uuml;nl\u0026uuml; N, \u0026Uuml;lk\u0026uuml; SG. Composite resin restorations in the last 10 years: A review with in vivo and in vitro studies. NEU Dent J. 2020;2(3):124-45.\u003c/li\u003e\n\u003cli\u003eKazak M, D\u0026ouml;nmez N. Development of dentin bonding systems from past to present. 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Current Adhesive Approaches and Clinical Adhesive Applications. 1st ed. Ankara: T\u0026uuml;rkiye Klinikleri; 2022. p.1-10.\u003c/li\u003e\n\u003cli\u003eChinelatti MA, Corona SA, Borsatto MC, Ribeiro LF, Rocha RA, Palma-Dibb RG. Analysis of surfaces and adhesive interfaces of enamel and dentin after different treatments. J Mater Sci Mater Med. 2007;18(7):1465-70.\u003c/li\u003e\n\u003cli\u003eLiu M, Xu X, Liu Q, Zhang K, Xin P. Effect of various Er:YAG laser conditioning energies on dentin surface: micromorphological investigation and dentin-resin shear bond strength test. Lasers Med Sci. 2023;38(1):242-50.\u003c/li\u003e\n\u003cli\u003eZakavi F, Gholizadeh S, Dibazar S, Esmaeili M. A comparison of laser and mechanical surface pretreatment methods on shear bond strength of resin composite to resin-modified glass ionomer. J Dent (Shiraz). 2023;24:103-11.\u003c/li\u003e\n\u003cli\u003eAzimi N, Mohammadi N, Parsaie Z, Fereidouni K. 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J Dent Res. 2007;86(3):232-6.\u003c/li\u003e\n\u003cli\u003eGhavamnasiri M, Eslami S, Ameri H, Chasteen JE, Majidinia S, Moghadam FV. Effect of amalgam corrosion products in non-discolored dentin on the bond strength of replaced composite resin. J Conserv Dent. 2015;18(1):25-9.\u003c/li\u003e\n\u003cli\u003eMandava J, Pamidimukkala S, Karumuri S, Ravi R, Borugadda R, Afraaz A. Microtensile bond strength evaluation of composite resin to discolored dentin after amalgam removal. Cureus. 2020;12(4):e7536.\u003c/li\u003e\n\u003cli\u003eScholtanus JD, Ozcan M, Huysmans MC. Penetration of amalgam constituents into dentine. J Dent. 2009;37(5):366-73.\u003c/li\u003e\n\u003cli\u003eGuven Y, Aktoren O. Shear bond strength and ultrastructural interface analysis of different adhesive systems to Er:YAG laser-prepared dentin. Lasers Med Sci. 2015;30(2):769-78.\u003c/li\u003e\n\u003cli\u003eZhang Y, Jiang A. The influence of Er:YAG laser treatment on the shear bond strength of enamel and dentin: a systematic review and meta-analysis. Quintessence Int. 2020;51:8-16.\u003c/li\u003e\n\u003cli\u003eSun G, Chen X, Wei F, Bai T, Zhu S. Effects of Er:YAG, Er,Cr:YSGG, and Nd:YAG laser irradiation and adhesive systems on the immediate and long-term bond strength of dentin: a systematic review and meta-analysis. Lasers Med Sci. 2023;38(1):32-53.\u003c/li\u003e\n\u003cli\u003eWei D, Nakamoto A, Hiraishi N, Nakane A, Abuna G, Otsuki M, et al. Effect of Er:YAG laser irradiation with additional low energy on resin-dentin bonding and morphology of bonded interface. J Mech Behav Biomed Mater. 2023;140:105692.\u003c/li\u003e\n\u003cli\u003eUsumez A, Sari T, Seseogullari Dirihan R, Esad Guven M, Ahmet SO, Gutknecht N. Effect of acid or laser treatment on degradation of dentin matrix. Lasers Dent Sci. 2022;6:99-105.\u003c/li\u003e\n\u003cli\u003eKaptan A, Oznurhan F. Effects of Er:YAG and Er,Cr:YSGG laser irradiation and adhesive systems on microtensile bond strength of a self-adhering composite. Lasers Med Sci. 2023;38(1):41-9.\u003c/li\u003e\n\u003cli\u003eNagarkar S, Theis-Mahon N, Perdig\u0026atilde;o J. Universal dental adhesives: Current status, laboratory testing, and clinical performance. J Biomed Mater Res B Appl Biomater. 2019;107(6):2121-31.\u003c/li\u003e\n\u003cli\u003eSezinando A, Perdig\u0026atilde;o J, Ceballos L. Long-term in vitro adhesion of polyalkenoate-based adhesives to dentin. J Adhes Dent. 2017;19(4):305-16.\u003c/li\u003e\n\u003cli\u003eBrkanović S, Sever EK, Vukelja J, Ivica A, Miletić I, Krmek SJ. Comparison of different universal adhesive systems on dentin bond strength. Materials (Basel). 2023;16(4):1530.\u003c/li\u003e\n\u003cli\u003eCruz J, Delgado AHS, F\u0026eacute;lix S, Brito J, Gon\u0026ccedil;alves L, Polido M. Improving properties of an experimental universal adhesive by adding a multifunctional dendrimer (G-IEMA): Bond strength and nanoleakage evaluation. Polymers. 2022;14(7):1462.\u003c/li\u003e\n\u003cli\u003eZubrzycki J, Klepka T, Marchewka M, Zubrzycki R. Tests of dental properties of composite materials containing nanohybrid filler. Materials. 2023;16(1):348-64.\u003c/li\u003e\n\u003cli\u003eKaradaglioglu OI, Alagoz LG, Caliskan A, Vaizoglu GA. The effect of different surface roughening systems on the micro-shear bond strength of aged resin composites. Niger J Clin Pract. 2022;25(1):37-43.\u003c/li\u003e\n\u003cli\u003eOzcan M, Cura C, Brendeke J. Effect of aging conditions on the repair bond strength of a microhybrid and a nanohybrid resin composite. J Adhes Dent. 2010;12(6):451-9.\u003c/li\u003e\n\u003cli\u003eOuchi H, Takamizawa T, Tsubota K, Tsujimoto A, Imai A, Barkmeier WW, et al. The effects of aluminablasting on bond durability between universal adhesives and tooth substrate. Oper Dent. 2020;45(2):196-208.\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"Amalgam contamination, Composite resin, Adhesive system, Dental laser, Bond strength","lastPublishedDoi":"10.21203/rs.3.rs-7115069/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-7115069/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003ch2\u003eBackground\u003c/h2\u003e\u003cp\u003eThe aim of this study was to investigate the bond strength of resin composites to dentin surfaces following the removal of amalgam restorations.\u003c/p\u003e\u003ch2\u003eMethods\u003c/h2\u003e\u003cp\u003eTwenty-seven amalgam-restored molars were selected, and their amalgam restorations were removed. The exposed dentin surfaces were subjected to different surface treatments: ortho-phosphoric acid etching, sandblasting, and Er:YAG laser irradiation. Following surface treatment, the samples were divided into three subgroups and restored using different universal adhesives (Solare Universal Bond, Gluma Bond Universal, Scotchbond Universal Plus) and nanohybrid composite resins (G-aenial A'CHORD, Charisma Topaz, Filtek Z550). Microshear bond strength (\u0026micro;SBS) testing was conducted for each group. The data were statistically analysed using one-way analysis of variance (ANOVA) and Tukey\u0026rsquo;s post-hoc test.\u003c/p\u003e\u003ch2\u003eResults\u003c/h2\u003e\u003cp\u003eThe highest bond strength was observed in the 3M subgroup (39.91 MPa) on laser-treated dentin surfaces, while the lowest bond strength was recorded in the Kulzer subgroup (3.61 MPa) on sandblasted surfaces.\u003c/p\u003e\u003ch2\u003eConclusions\u003c/h2\u003e\u003cp\u003eSurface modification of amalgam-contaminated dentin, particularly with laser treatment, enhanced the adhesion of composite resin and yielded successful bond strength outcomes.\u003c/p\u003e","manuscriptTitle":"Effect of surface modification methods on dentin-resin bond strength after amalgam contamination: In-vitro study","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-07-30 11:43:04","doi":"10.21203/rs.3.rs-7115069/v1","editorialEvents":[{"type":"communityComments","content":0}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"e094409e-005b-48d8-9091-e98a5704cd34","owner":[],"postedDate":"July 30th, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[],"tags":[],"updatedAt":"2025-08-27T02:38:41+00:00","versionOfRecord":[],"versionCreatedAt":"2025-07-30 11:43:04","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-7115069","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-7115069","identity":"rs-7115069","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}