Evaluating the effectiveness of low-level laser therapy in reducing local anesthesia injection pain in children

Evaluating the effectiveness of low-level laser therapy in reducing local anesthesia injection pain in children | 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 Article Evaluating the effectiveness of low-level laser therapy in reducing local anesthesia injection pain in children Ansam Shafik Alafandy, MHD Abdulrahman MHD Bader Aldin Almourabet This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-4243790/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 Aim The aim of this study was to evaluate the efficacy of low-level laser therapy (LLLT) in reducing the pain of needle injection during local anesthesia in children. Materials and Methods Twenty cooperative healthy kids participated in this research; their ages were between 8-12 years old. In laser group (LG) LLLT diode laser (635 nm; continuous mode; 100 mW; 48.0 J/cm 2 ) was applied buccally in one side of the mandibula or maxilla in contact with the soft tissue for 120 second. While in the contralateral side 20% Benzocaine Gel topical anesthetic was applied for the same time and this was the control group (CG). Then a short needle was inserted in each side and the pain was evaluated for each side separately using the Wong-Baker Faces Pain Rating Scale (PRS). Non-parametric analysis was applied and data were analyzed for statistical significance (p < 0.05). Results The total cases were twenty, (10 in the maxilla and 10 in the mandible). The "no pain" and "severe pain" rates in the PRS were 41.7% and 3.3% for the LG and 21.7% and 11.7% for the CG, respectively, during injection. The mean pain degree was 2.6 in CG while it was 1.2 in LG. Wilcoxon analysis revealed a statistically significant difference between LG and CG (P=0.001<0.05). While there was no significant difference in evaluating pain degree according to the order of technique, gender, place of injection, previous dental experiment, and behavior assessment in both methods. Conclusion Administration of LLLT diode laser (635 nm) can be considered for decreasing pain of injection in children and it is more effective than 20% Benzocaine topical anesthetic gel, regardless the order of technique, gender, place of injection, previous dental experiment, and behavior assessment. Health sciences/Health care Health sciences/Medical research Anesthesia low- level laser pain topical Figures Figure 1 Figure 2 Introduction Unpleasant dental experience arises from the first painful procedure for the child in his life, which produces a patient with dental anxiety and dental phobia for the rest of his life. Reducing pain during dental treatment is an important issue in pediatric dentistry to have a cooperative patient, so huge efforts were done to achieve this goal by using different ways such as conscious and unconscious sedation. Injection is one of the scary tools in dentistry and unfortunately it is the first step in most treatments. Topical anesthesia gel is a good and acceptable way to reduce injection pain in children. However; while using them, careful attention must be paid to their pharmacology, area and duration of application, age and weight of the patients and possible side effects [ 1 ]. For its great effects, low power laser therapy has become a popular treatment modality. [ 1 ] Lasers can be classified into high- and low-level lasers where a high-level laser can lead to tissue ablation and cutting, while a low-level laser is able to infiltrate the tissues [ 2 ] In 1967, Dr. Endre Mester was the first to observe the effects of low level laser therapy LLLT in mice [ 3 ], which also known as photobiomodulation therapy (PBMT). PBMT relies on applying light from a low-energy laser or light emitting diodes (LEDs) lights with specific wavelength spectrum of 600–1110 nm to stimulate cellular and tissue responses [ 4 ] [ 5 , 6 ]. The differences between all wavelengths are related to the specific absorption coefficient of tissue components to the incident laser beam wavelength [ 7 ] [ 8 ] . Diode lasers (DL) is set to low power and a diffused, defocused radius. It does not cause the overheating of tissues and penetrates deeply, so it is named cold laser [ 7 ] [ 8 ]. DL active medium is a solid-state semiconductor made of aluminum, gallium, arsenide, and occasionally indium, which produces laser wavelengths, ranging from approximately 810 nm to 980 nm. All diode wavelengths are absorbed primarily by tissue pigment melanin and hemoglobin. Conversely, they are poorly absorbed by the hydroxyapatite and water present in the enamel [ 9 ]. DL is used in soft tissue operations, i.e., incisions, excisions, microbial load reduction, teeth whitening, and photobiomodulation. It was found to have analgesic and bio-modulative effects, so it has been widely used in dental practice for the management of dentine hypersensitivity, soft tissue disorders, musculoskeletal pain, and for stimulating bone regeneration. [ 10 ] [ 7 ] [ 8 ] Low-level laser therapy (LLLT) can offer tremendous therapeutic benefits to patients, such as accelerated wound healing and pain relief [ 11 ]. Many research have reported that LLLT is able to control pain in different therapy in dentistry such as surgical and orthodontic treatment, besides it is efficacy in diminishing temporomandibular joint disorders pain [ 12 ] [ 13 ], or even in Pulpal anesthesia [ 14 ]. The exact mechanisms responsible for the apparent analgesic effect of LLLT are still unclear [ 15 ]. It is assumed that perhaps LLLT has anti-inflammatory and neural regenerative properties as a probable result of the biological reactions that stimulate cell differentiation and proliferation, enabling it to have antinociceptive effects. [ 16 ] LLLT may act via numerous mechanisms of action, including facilitating the release of endogenous opioids, augmenting tissue repair and cellular respiration, increasing vasodilatation and pain threshold, and decreasing inflammation [ 17 ]. Although many previous studies revealed a positive effects of LLLT on injection pain and anesthesia efficacy during local anesthesia [ 18 ] [ 19 ], however those research are still very few, especially in children. Thus, this study aims to evaluate the efficacy of low-level laser therapy in reducing the pain of needle injection during local anesthesia in children. Materials and Methods The ethical clearance was obtained from the Research Ethics Committee, Dental Collage, Al-Sham Private University (ASPU), Damascus, Syria (Ref: Project No. 252-4‐4‐2023). All research was performed in accordance with the Declaration of Helsinki, and informed consent was obtained from all participants parents or legal guardians. Sample size Twenty healthy kids from the patients of the department of pedodontics in ASPU were enrolled in this clinical trial; their ages were between 8–12 years old (mean age was 9.9 Y); twelve male and eight female. All participated children were cooperative with Frankel behavioral ratings 3 (Positive acceptance of treatment) and 4 (Definitely positive good rapport with the dentist) [ 11 ] [ 20 ]. Before starting any clinical procedure, tell-show‐do behavior management technique has been provided for both studied techniques. Exclusion criteria Uncooperative children; with Frankel behavioral ratings 1 and 2 [ 11 ] [ 20 ]. Children who are medically compromised or special needed. Children with a history of allergy to Benzocaine Children with hard pain, such as acute pulpitis pain. Study design A split-mouth study was conducted. One side, was the laser group (LG); and the other side was the topical anesthesia control group (CG). Each group consisted of twenty cases. Laser Group For laser administration both doctor and child have put on Laser Safety Glasses, then mucosa was dried and the BIO handpiece was used and LLLT diode laser (Triplo, MEDENCY, Italy) (Fig. 1 ,a), of 635 nm wave length; continuous mode; output power 100 mW; 48.0 J/cm2, was administrated buccally in one side of the mandibula or maxilla in contact with the soft tissue for 120 second, and 5mm application diameter (Fig. 1 ,b). Control Group In the contralateral side in the same jaw, after drying the mucosa, a pea size of 20% Benzocaine (Iolite Topical Anesthetic Gel, USA) was applied by cotton bud for 120 second. Then after laser or Benzocaine application a short dental needle 25mm; 27 gauge (MAHAJECT, China) was inserted for 2–3 mm into the buccal sulcus adjacent to the tooth to be treated. In each side the needle was inserted directly after preanesthetic agent was applied. A new sharp needle was used in each side in order not to cause additional pain by using blunt needle. The order of technique application was chosen by lottery method randomly. All cases were done in the buccal sulcus of the maxilla or mandibula. Then by the help of another doctor, who did not know which technique was applied, pain was evaluated for each side separately. The child was asked to choose one face of Wong-Baker Faces Pain Rating Scale [ 12 ]. The Wong-Baker Faces Pain Rating Scale (FACES Scale) is self‐assessment tool has six degrees; 0: No Hurt, 2; Hurts Little Bit, 4; Hurts Little More, 6; Hurts Even More, 8; Hurts Whole Lot, 10; Hurts Worst. It is used with children ages 3 and older, This scale is intended to measure how children feel, not how their face looks [ 13 ]. SPSS version.25 was used to analyze the data. Non-parametric analysis was applied and data 96 were analyzed for statistical significance (p < 0.05). Results In this study twenty cases were administrated in each group; ten in the upper jaw and ten in the lower jaw. The percent of pain degrees for cases of LG and CG in Fig. 2 . The mean pain degree in LG was less than that of CG. Table 1 Table 1 Mean of pain degree in LG and CG N Minimum Maximum Mean Std. Deviation Age 20 8 12 9.90 1.334 Pain degree in LG 20 0 6 1.20 1.642 Pain degree in CG 20 0 6 2.50 1.433 Since our sample size was small, less than 30, a Kolmogorov-Smirnov test was done and revealed that P = 0.000 < 0.05 which meant that our data did not fit a normal distribution, thus and a nonparametric test was warranted. Only one case shows a higher pain degree in LLLT than topical gel therapy (TGT), while 14 cases registered a lower pain degree in LLLT comparing to TGT, and the pain was at the same degree in both therapy in the other five cases. Wilcoxon Signed Ranks Test revealed that the pain degree in LG was lower than that in CG with a significant statistical difference between the two methods (P = 0.001 < 0.05), Table 2 . Table 2 Distribution of cases in both technique N Mean Rank Sum of Ranks Pain evaluation in LG – pain Negative Ranks 1 a 8.00 8.00 evaluation in CG Positive Ranks 14 b 8.00 112.00 Ties 5 c Total 20 Effect of order of technique: TGT was the first applicated method in four children, while LLLT was the first one in the rest. Mann-Whitney test was done to evaluate the effect of the order of application of two technique. P = 0.957 > 0.05 when TGT was firstly used, and P = 1.000 > 0.05 when LLLT was firstly used. So, there was no significant difference between the order of two technique. Thus, there was no effect of the order of technique application on pain degree in both methods. Effect of gender: Twelve males and eight females were participated in this study. When comparing between pain degree in males and females, Mann-Whitney test revealed P = 0.930 > 0.05 when TGT was administrated, and P = 0.729 > 0.05 when LLLT was administrated. So, there was no significant difference between males and females in both groups. Effect of place of injection: Ten cases were conducted in the maxilla and ten cases in the mandibula. Mann-Whitney test was done to evaluate the effect of the place of application. P = 0.897 > 0.05 when TGT was administrated, and P = 1.000 > 0.05 when LLLT was administrated. So, there was no significant difference between the upper and lower jaw in both groups. Effect of previous dental experiment: Fourteen cases had a previous unpleasant dental experiment, while six cases had not. Mann-Whitney test revealed P = 0.121 > 0.05 when TGT was administrated, and P = 0.404 > 0.05 when LLLT was administrated. So, there was no significant difference between the children with or without previous dental experiment in both groups. Effect of behavior assessment: Fourteen children were positive and six were absolute positive according to Frankel behavioral ratings 3 and 4. Mann-Whitney test revealed P = 0.100 > 0.05 when TGT was administrated, and P = 0.404 > 0.05 when LLLT was administrated. So, there was no significant difference between 3 and 4 rates in both groups. Discussion Due to the analgesic effect of laser, researchers studied the effect of LLLT diode laser in reducing the injection pain associated with dental local anesthesia. Previous studies used different pain scales; either modified behavioral pain scale (MBPS) [ 14 ], or FACES Scale [ 15 ], or visual analog scale (VAS) [ 16 ] [ 9 ] [ 17 ] [ 14 ], or Face, Legs, Activity, Cry, Consolability (FLACC) scale [ 10 ]. In our study FACES Scale was adopted because it shows a close linear relationship with visual analogue pain scales for kids of three-year age and older. It is easy to administer and requires no equipment except for the photocopied faces [ 13 ]. And this scale measures how children feel, and pain degree has not been assessed by another person, so this added more reliability for pain degree evaluating. Researchers used different variables trying to find the most appropriate parameters to get the best effect. To the best of our knowledge, there was no published study tried LLLT diode laser of 635 nm for 120 seconds as preanesthetic factor to decrease pain of injection. So, the current research adopted this wave length and conducted this clinical trial in children because most of prior research were conducted on adults, except few published studies were directed in children, such as Seraj, Bavaghar et al. 2023 besides the study of Shekarchi, F., et al., 2022, and Uçar, G., Ü. Şermet Elbay, 2022. Thus, we compared our study results with similar available studies in both adults and children. The current study revealed a lower mean of pain degree in LG (1.20) than that of CG (2.50), and this result disagree with Tuk, van Wijk et al. 2017 study which conducted in adults and indicated that preinjection LLLT did not effectively decrease the pain felt during local anesthetic injections before third molar surgery,; where targeted injection site was irradiated twice with 198 mW continuous wave for 30 seconds with a 0.088 cm2 focal spot at an applied energy of 5.94 J and fluence of 67.50 J/cm2 [ 18 ], and this disagreement may due to the different parameters used in each study. While the current study agree with that of Sattayut, 2014 (790 nm, 2 minutes), Jagtap et al., 2019 (660 nm, 3 minutes) and Ghabraei, S., et al., 2020 (980 nm, 1 minute) in adults [ 16 ] [ 9 ] [ 17 ]. As well as, agree with the study of Shekarchi, F., et al., 2022 (808 nm, 1 minute), Uçar, G., Ü. Şermet Elbay, 2022 (810 nm, 20 seconds), and Seraj, Bavaghar et al. 2023 (810 nm, 13 seconds) in children [ 15 ] [ 10 ] [ 14 ]. However, the difference in pain degree between laser group and control group was statistically significant in only two of those above-mentioned studies, in Jagtap et al., 2019 in adults and Uçar, G., Ü. Şermet Elbay, 2022 in children [ 9 ] [ 10 ], and it was statistically significant in our study as well. Thus, according to previous results, LLLT diode laser (635 nm; continuous mode; 100 mW; 48.0 J/cm2) decreased pain level of local anesthesia injection with superiority over 20% Benzocaine topical anesthetic gel. In this research there was no effect of the order of technique, patient gender, place of injection, and previous dental experiment on pain degree in both methods. As well as; there was no significant difference between positive and absolute positive children in pain degree evaluation of both methods. Unfortunately, there was not any available research about using LLLT in topical anesthesia that studied those variables, so we could not compare our results with similar research. However, maybe we could not find any effect of those variables on pain degree due to choosing only cooperative children. It is important to shed light on the positive effect of the basic behavior management techniques, like tell-show‐do, and the distraction impact of the protective glasses were used during LLLT administration, which may affect the assessment of pain degree by the child, and this psychological factor may tip the equation in favor of the laser. Unfortunately, our sample size was small because it was so difficult to convince parents with safety of LLLT, on the other hand it was not easy to find cooperative children to accept treatment procedure. Thus, we recommend to do further studies with larger sample size. Conclusion Administration of LLLT diode laser (635 nm) can be considered for decreasing pain of injection in children and it is more effective than 20% Benzocaine topical anesthetic gel, regardless the order of technique, gender, place of injection, previous dental experiment, and behavior assessment. However, further studies are still needed to provide more robust evidence. Declarations Author Contribution Ansam Shafik Alafandy designed the study protocol, and wrote the manuscript text. MHD Abdulrahman MHD Bader Aldin Almourabet performed the in vivo experiments. Ansam Shafik Alafandy and MHD Abdulrahman MHD Bader Aldin Almourabet analyzed the data. Acknowledgement The authors thank Dr. Sharif Ashkar, Dr. Hazem Sawaf, Dr. Alaa Homsi and Engineer. Muhannad Abdulmajeed, as well as Dr. Razan Kubaissy, Mr. Shafik Alafandy, Mrs. Aisha Sheikho, for their great support. Data Availability The datasets analysed during the current study are not publicly available because this research is a part of wider study which has not finished yet, but are available from the corresponding author on reasonable request. References Baxter, D., Laser acupuncture analgesia: an overview . Acupuncture in Medicine, 1989. 6(2): p. 57–60. Elgadi, R., Y. Sedky, and R. Franzen, The effectiveness of low-level laser therapy on orthodontic tooth movement: a systematic review . Lasers in Dental Science, 2023: p. 1–9. Jagtap, B., et al., Painless injections–a possibility with low level laser therapy . J Dent Anesth Pain Med, 2019. 19(3): p. 159–165. Annu, A., et al., Comparative evaluation of photobiomodulation therapy at 660 and 810 nm wavelengths on the soft tissue local anesthesia reversal in pediatric dentistry: an in-vivo study . J Dent Anesth Pain Med, 2023. 23(4): p. 229–236. Rando, R.G., et al., Effects of Photobiomodulation Using Low-Level Laser Therapy on Alveolar Bone Repair . Photonics, 2023. 10(7): p. 734. Dipalma, G., et al., Photobiomodulation and Growth Factors in Dentistry: A Systematic Review . Photonics, 2023. 10(10): p. 1095. Strakas, D. and R. Franzen, The blue wavelengths in laser dentistry: a review of current literature . Lasers in Dental Science, 2023. 7(2): p. 97–99. Malcangi, G., et al., Therapeutic and Adverse Effects of Lasers in Dentistry: A Systematic Review . Photonics, 2023. 10(6): p. 650. Hilgers, J.J. and S.G. Tracey, Clinical uses of diode lasers in orthodontics . Journal of clinical orthodontics: JCO, 2004. 38(5): p. 266–273. El-Qashty, R., O.A. Elkashty, and E. Hany, Therapeutic Potential of Low-Level Laser Photobiomodulation on Adjuvant Induced Temporomandibular Joint Arthritis in A Rat Model . Mansoura Journal of Dentistry, 2023. 10(1): p. 1–8. Sun, G. and J. Tunér, Low-level laser therapy in dentistry. Dent Clin North Am, 2004. 48(4): p. 1061-76, viii. Deana, N.F., et al., Effectiveness of Low-Level Laser Therapy in Reducing Orthodontic Pain: A Systematic Review and Meta-Analysis. Pain Res Manag, 2017. 2017: p. 8560652. Ahmad, S.A., et al., Low-level laser therapy in temporomandibular joint disorders: a systematic review . J Med Life, 2021. 14(2): p. 148–164. Hashemi, I.S.E., et al., Effects of Diode Low-Level Laser Therapy of 810 Nm on Pulpal Anesthesia of Maxillary Premolars: A Double-Blind Randomized Clinical Trial . European Endodontic Journal, 2021. 6(2): p. 155. Ren, C., C. McGrath, and Y. Yang, The effectiveness of low-level diode laser therapy on orthodontic pain management: a systematic review and meta-analysis . Lasers in Medical Science, 2015. 30(7): p. 1881–1893. Wu, S., et al., Effect of low-level laser therapy on tooth-related pain and somatosensory function evoked by orthodontic treatment . International Journal of Oral Science, 2018. 10(3): p. 22. Ahrari, F., et al., The efficacy of low-level laser therapy for the treatment of myogenous temporomandibular joint disorder . Lasers Med Sci, 2014. 29(2): p. 551–7. Jagtap, B., et al., Painless injections-a possibility with low level laser therapy . J Dent Anesth Pain Med, 2019. 19(3): p. 159–165. Uçar, G., Ü. Şermet Elbay, and M. Elbay, Effects of low level laser therapy on injection pain and anesthesia efficacy during local anesthesia in children: A randomized clinical trial . Int J Paediatr Dent, 2022. 32(4): p. 576–584. Narayan, V. and S. Samuel, Appropriateness of various behavior rating scales used in pediatric dentistry: A Review . J Global Oral Health, 2019. 2(2): p. 112–7. Additional Declarations No competing interests reported. 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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-4243790","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":307409320,"identity":"c03ac67f-bce9-4844-9f28-c1f63c699e63","order_by":0,"name":"Ansam Shafik Alafandy","email":"data:image/png;base64,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","orcid":"","institution":"Al-Sham Private University ASPU","correspondingAuthor":true,"prefix":"","firstName":"Ansam","middleName":"Shafik","lastName":"Alafandy","suffix":""},{"id":307409321,"identity":"744df805-3fe4-4993-be7d-06728876f6cd","order_by":1,"name":"MHD Abdulrahman MHD Bader Aldin Almourabet","email":"","orcid":"","institution":"Al-Sham Private University ASPU","correspondingAuthor":false,"prefix":"","firstName":"MHD","middleName":"Abdulrahman MHD Bader Aldin","lastName":"Almourabet","suffix":""}],"badges":[],"createdAt":"2024-04-09 19:29:12","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-4243790/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-4243790/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":57629933,"identity":"7865f870-d10c-4f00-95c4-4780d41df5fc","added_by":"auto","created_at":"2024-06-03 14:38:41","extension":"jpeg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":383961,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cstrong\u003eTriplo the three waves device, MEDENCY, Italy (a); ten-year-old child during LLLT (b).\u003c/strong\u003e\u003c/p\u003e","description":"","filename":"floatimage1.jpeg","url":"https://assets-eu.researchsquare.com/files/rs-4243790/v1/b2de7f207120056872b94cfb.jpeg"},{"id":57629932,"identity":"f578f541-b9f6-4934-8207-0f54f0a5408b","added_by":"auto","created_at":"2024-06-03 14:38:41","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":14403,"visible":true,"origin":"","legend":"\u003cp\u003e\u003cem\u003e\u003cstrong\u003eDistribution of sample according to degree pain in CG and LG\u003c/strong\u003e\u003c/em\u003e\u003c/p\u003e","description":"","filename":"2.png","url":"https://assets-eu.researchsquare.com/files/rs-4243790/v1/443b71ff76193c22e097e3fd.png"},{"id":57691801,"identity":"43e362cd-92d5-462e-9f20-747b64daa818","added_by":"auto","created_at":"2024-06-04 11:33:10","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":824065,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-4243790/v1/e2eb9f23-518e-4e0d-8549-5504f0bef0ad.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Evaluating the effectiveness of low-level laser therapy in reducing local anesthesia injection pain in children","fulltext":[{"header":"Introduction","content":"\u003cp\u003eUnpleasant dental experience arises from the first painful procedure for the child in his life, which produces a patient with dental anxiety and dental phobia for the rest of his life. Reducing pain during dental treatment is an important issue in pediatric dentistry to have a cooperative patient, so huge efforts were done to achieve this goal by using different ways such as conscious and unconscious sedation. Injection is one of the scary tools in dentistry and unfortunately it is the first step in most treatments. Topical anesthesia gel is a good and acceptable way to reduce injection pain in children. However; while using them, careful attention must be paid to their pharmacology, area and duration of application, age and weight of the patients and possible side effects [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eFor its great effects, low power laser therapy has become a popular treatment modality. [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e] Lasers can be classified into high- and low-level lasers where a high-level laser can lead to tissue ablation and cutting, while a low-level laser is able to infiltrate the tissues [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e] In 1967, Dr. Endre Mester was the first to observe the effects of low level laser therapy LLLT in mice [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e], which also known as photobiomodulation therapy (PBMT). PBMT relies on applying light from a low-energy laser or light emitting diodes (LEDs) lights with specific wavelength spectrum of 600\u0026ndash;1110 nm to stimulate cellular and tissue responses [\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e] [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e, \u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e]. The differences between all wavelengths are related to the specific absorption coefficient of tissue components to the incident laser beam wavelength [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e] [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e] .\u003c/p\u003e \u003cp\u003eDiode lasers (DL) is set to low power and a diffused, defocused radius. It does not cause the overheating of tissues and penetrates deeply, so it is named cold laser [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e] [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. DL active medium is a solid-state semiconductor made of aluminum, gallium, arsenide, and occasionally indium, which produces laser wavelengths, ranging from approximately 810 nm to 980 nm. All diode wavelengths are absorbed primarily by tissue pigment melanin and hemoglobin. Conversely, they are poorly absorbed by the hydroxyapatite and water present in the enamel [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. DL is used in soft tissue operations, i.e., incisions, excisions, microbial load reduction, teeth whitening, and photobiomodulation. It was found to have analgesic and bio-modulative effects, so it has been widely used in dental practice for the management of dentine hypersensitivity, soft tissue disorders, musculoskeletal pain, and for stimulating bone regeneration. [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e] [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e] [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]\u003c/p\u003e \u003cp\u003eLow-level laser therapy (LLLT) can offer tremendous therapeutic benefits to patients, such as accelerated wound healing and pain relief [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e]. Many research have reported that LLLT is able to control pain in different therapy in dentistry such as surgical and orthodontic treatment, besides it is efficacy in diminishing temporomandibular joint disorders pain [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e] [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e], or even in Pulpal anesthesia [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. The exact mechanisms responsible for the apparent analgesic effect of LLLT are still unclear [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e]. It is assumed that perhaps LLLT has anti-inflammatory and neural regenerative properties as a probable result of the biological reactions that stimulate cell differentiation and proliferation, enabling it to have antinociceptive effects. [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e] LLLT may act via numerous mechanisms of action, including facilitating the release of endogenous opioids, augmenting tissue repair and cellular respiration, increasing vasodilatation and pain threshold, and decreasing inflammation [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eAlthough many previous studies revealed a positive effects of LLLT on injection pain and anesthesia efficacy during local anesthesia [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e] [\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e], however those research are still very few, especially in children.\u003c/p\u003e \u003cp\u003eThus, this study aims to evaluate the efficacy of low-level laser therapy in reducing the pain of needle injection during local anesthesia in children.\u003c/p\u003e"},{"header":"Materials and Methods","content":"\u003cp\u003e The ethical clearance was obtained from the Research Ethics Committee, Dental Collage, Al-Sham Private University (ASPU), Damascus, Syria (Ref: Project No. 252-4‐4‐2023).\u003c/p\u003e \u003cp\u003e All research was performed in accordance with the Declaration of Helsinki, and informed consent was obtained from all participants parents or legal guardians.\u003c/p\u003e \u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eSample size\u003c/h2\u003e \u003cp\u003eTwenty healthy kids from the patients of the department of pedodontics in ASPU were enrolled in this clinical trial; their ages were between 8\u0026ndash;12 years old (mean age was 9.9 Y); twelve male and eight female. All participated children were cooperative with Frankel behavioral ratings 3 (Positive acceptance of treatment) and 4 (Definitely positive good rapport with the dentist) [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e] [\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e]. Before starting any clinical procedure, tell-show‐do behavior management technique has been provided for both studied techniques.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec4\" class=\"Section2\"\u003e \u003ch2\u003eExclusion criteria\u003c/h2\u003e \u003cp\u003e \u003cul\u003e \u003cli\u003e \u003cp\u003eUncooperative children; with Frankel behavioral ratings 1 and 2 [\u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e] [\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e].\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eChildren who are medically compromised or special needed.\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eChildren with a history of allergy to Benzocaine\u003c/p\u003e \u003c/li\u003e \u003cli\u003e \u003cp\u003eChildren with hard pain, such as acute pulpitis pain.\u003c/p\u003e \u003c/li\u003e \u003c/ul\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec5\" class=\"Section2\"\u003e \u003ch2\u003eStudy design\u003c/h2\u003e \u003cp\u003eA split-mouth study was conducted. One side, was the laser group (LG); and the other side was the topical anesthesia control group (CG). Each group consisted of twenty cases.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec6\" class=\"Section2\"\u003e \u003ch2\u003eLaser Group\u003c/h2\u003e \u003cp\u003eFor laser administration both doctor and child have put on Laser Safety Glasses, then mucosa was dried and the BIO handpiece was used and LLLT diode laser (Triplo, MEDENCY, Italy) (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e,a), of 635 nm wave length; continuous mode; output power 100 mW; 48.0 J/cm2, was administrated buccally in one side of the mandibula or maxilla in contact with the soft tissue for 120 second, and 5mm application diameter (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003e,b).\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec7\" class=\"Section2\"\u003e \u003ch2\u003eControl Group\u003c/h2\u003e \u003cp\u003eIn the contralateral side in the same jaw, after drying the mucosa, a pea size of 20% Benzocaine (Iolite Topical Anesthetic Gel, USA) was applied by cotton bud for 120 second.\u003c/p\u003e \u003cp\u003eThen after laser or Benzocaine application a short dental needle 25mm; 27 gauge (MAHAJECT, China) was inserted for 2\u0026ndash;3 mm into the buccal sulcus adjacent to the tooth to be treated. In each side the needle was inserted directly after preanesthetic agent was applied. A new sharp needle was used in each side in order not to cause additional pain by using blunt needle. The order of technique application was chosen by lottery method randomly. All cases were done in the buccal sulcus of the maxilla or mandibula.\u003c/p\u003e \u003cp\u003eThen by the help of another doctor, who did not know which technique was applied, pain was evaluated for each side separately. The child was asked to choose one face of Wong-Baker Faces Pain Rating Scale [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e].\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eThe Wong-Baker Faces Pain Rating Scale (FACES Scale) is self‐assessment tool has six degrees; 0: No Hurt, 2; Hurts Little Bit, 4; Hurts Little More, 6; Hurts Even More, 8; Hurts Whole Lot, 10; Hurts Worst. It is used with children ages 3 and older, This scale is intended to measure how children feel, not how their face looks [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eSPSS version.25 was used to analyze the data. Non-parametric analysis was applied and data 96 were analyzed for statistical significance (p\u0026thinsp;\u0026lt;\u0026thinsp;0.05).\u003c/p\u003e \u003c/div\u003e"},{"header":"Results","content":"\u003cp\u003eIn this study twenty cases were administrated in each group; ten in the upper jaw and ten in the lower jaw. The percent of pain degrees for cases of LG and CG in Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eThe mean pain degree in LG was less than that of CG. Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\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\u003eMean of pain degree in LG and CG\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"6\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" 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=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eN\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\u003eStd. Deviation\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eAge\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e20\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e12\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e9.90\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e1.334\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePain degree in LG\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e20\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e1.20\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e1.642\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePain degree in CG\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e20\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e2.50\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c6\"\u003e \u003cp\u003e1.433\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cp\u003eSince our sample size was small, less than 30, a Kolmogorov-Smirnov test was done and revealed that P\u0026thinsp;=\u0026thinsp;0.000\u0026thinsp;\u0026lt;\u0026thinsp;0.05 which meant that our data did not fit a normal distribution, thus and a nonparametric test was warranted.\u003c/p\u003e \u003cp\u003eOnly one case shows a higher pain degree in LLLT than topical gel therapy (TGT), while 14 cases registered a lower pain degree in LLLT comparing to TGT, and the pain was at the same degree in both therapy in the other five cases.\u003c/p\u003e \u003cp\u003eWilcoxon Signed Ranks Test revealed that \u003cb\u003ethe pain degree in LG was lower than that in CG with a significant statistical difference\u003c/b\u003e between the two methods (P\u0026thinsp;=\u0026thinsp;0.001\u0026thinsp;\u0026lt;\u0026thinsp;0.05), Table \u003cspan refid=\"Tab2\" class=\"InternalRef\"\u003e2\u003c/span\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\u003eDistribution of cases in both technique\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"5\"\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=\"char\" char=\".\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e\u0026nbsp;\u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eN\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003eMean Rank\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003eSum of Ranks\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003ePain evaluation in LG \u0026ndash; pain\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eNegative Ranks\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e1\u003csup\u003ea\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e8.00\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e8.00\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\" morerows=\"2\" rowspan=\"3\"\u003e \u003cp\u003eevaluation in CG\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003ePositive Ranks\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e14\u003csup\u003eb\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c4\"\u003e \u003cp\u003e8.00\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c5\"\u003e \u003cp\u003e112.00\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eTies\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e5\u003csup\u003ec\u003c/sup\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c2\"\u003e \u003cp\u003eTotal\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c3\"\u003e \u003cp\u003e20\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"left\" colname=\"c4\"\u003e\u0026nbsp;\u003c/td\u003e \u003ctd align=\"left\" colname=\"c5\"\u003e\u0026nbsp;\u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e \u003cdiv id=\"Sec9\" class=\"Section2\"\u003e \u003ch2\u003eEffect of order of technique:\u003c/h2\u003e \u003cp\u003eTGT was the first applicated method in four children, while LLLT was the first one in the rest.\u003c/p\u003e \u003cp\u003eMann-Whitney test was done to evaluate the effect of the order of application of two technique. P\u0026thinsp;=\u0026thinsp;0.957\u0026thinsp;\u0026gt;\u0026thinsp;0.05 when TGT was firstly used, and P\u0026thinsp;=\u0026thinsp;1.000\u0026thinsp;\u0026gt;\u0026thinsp;0.05 when LLLT was firstly used. So, there was no significant difference between the order of two technique. Thus, there was \u003cb\u003eno effect\u003c/b\u003e of the order of technique application on pain degree in both methods.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec10\" class=\"Section2\"\u003e \u003ch2\u003eEffect of gender:\u003c/h2\u003e \u003cp\u003eTwelve males and eight females were participated in this study. When comparing between pain degree in males and females, Mann-Whitney test revealed P\u0026thinsp;=\u0026thinsp;0.930\u0026thinsp;\u0026gt;\u0026thinsp;0.05 when TGT was administrated, and P\u0026thinsp;=\u0026thinsp;0.729\u0026thinsp;\u0026gt;\u0026thinsp;0.05 when LLLT was administrated. So, there was no significant difference between males and females in both groups.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec11\" class=\"Section2\"\u003e \u003ch2\u003eEffect of place of injection:\u003c/h2\u003e \u003cp\u003eTen cases were conducted in the maxilla and ten cases in the mandibula. Mann-Whitney test was done to evaluate the effect of the place of application. P\u0026thinsp;=\u0026thinsp;0.897\u0026thinsp;\u0026gt;\u0026thinsp;0.05 when TGT was administrated, and P\u0026thinsp;=\u0026thinsp;1.000\u0026thinsp;\u0026gt;\u0026thinsp;0.05 when LLLT was administrated. So, there was no significant difference between the upper and lower jaw in both groups.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec12\" class=\"Section2\"\u003e \u003ch2\u003eEffect of previous dental experiment:\u003c/h2\u003e \u003cp\u003eFourteen cases had a previous unpleasant dental experiment, while six cases had not. Mann-Whitney test revealed P\u0026thinsp;=\u0026thinsp;0.121\u0026thinsp;\u0026gt;\u0026thinsp;0.05 when TGT was administrated, and P\u0026thinsp;=\u0026thinsp;0.404\u0026thinsp;\u0026gt;\u0026thinsp;0.05 when LLLT was administrated. So, there was no significant difference between the children with or without previous dental experiment in both groups.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec13\" class=\"Section2\"\u003e \u003ch2\u003eEffect of behavior assessment:\u003c/h2\u003e \u003cp\u003eFourteen children were positive and six were absolute positive according to Frankel behavioral ratings 3 and 4. Mann-Whitney test revealed P\u0026thinsp;=\u0026thinsp;0.100\u0026thinsp;\u0026gt;\u0026thinsp;0.05 when TGT was administrated, and P\u0026thinsp;=\u0026thinsp;0.404\u0026thinsp;\u0026gt;\u0026thinsp;0.05 when LLLT was administrated. So, there was no significant difference between 3 and 4 rates in both groups.\u003c/p\u003e \u003c/div\u003e"},{"header":"Discussion","content":"\u003cp\u003eDue to the analgesic effect of laser, researchers studied the effect of LLLT diode laser in reducing the injection pain associated with dental local anesthesia. Previous studies used different pain scales; either modified behavioral pain scale (MBPS) [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e], or FACES Scale [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e], or visual analog scale (VAS) [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e] [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e] [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e] [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e], or Face, Legs, Activity, Cry, Consolability (FLACC) scale [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. In our study FACES Scale was adopted because it shows a close linear relationship with visual analogue pain scales for kids of three-year age and older. It is easy to administer and requires no equipment except for the photocopied faces [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. And this scale measures how children feel, and pain degree has not been assessed by another person, so this added more reliability for pain degree evaluating.\u003c/p\u003e \u003cp\u003eResearchers used different variables trying to find the most appropriate parameters to get the best effect. To the best of our knowledge, there was no published study tried LLLT diode laser of \u003cb\u003e635 nm\u003c/b\u003e for 120 seconds as preanesthetic factor to decrease pain of injection. So, the current research adopted this wave length and conducted this clinical trial in children because most of prior research were conducted on adults, except few published studies were directed in children, such as Seraj, Bavaghar et al. 2023 besides the study of Shekarchi, F., et al., 2022, and U\u0026ccedil;ar, G., \u0026Uuml;. Şermet Elbay, 2022. Thus, we compared our study results with similar available studies in both adults and children.\u003c/p\u003e \u003cp\u003eThe current study revealed a lower mean of pain degree in LG (1.20) than that of CG (2.50), and this result disagree with Tuk, van Wijk et al. 2017 study which conducted in adults and indicated that preinjection LLLT did not effectively decrease the pain felt during local anesthetic injections before third molar surgery,; where targeted injection site was irradiated twice with 198 mW continuous wave for 30 seconds with a 0.088 cm2 focal spot at an applied energy of 5.94 J and fluence of 67.50 J/cm2 [\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e], and this disagreement may due to the different parameters used in each study.\u003c/p\u003e \u003cp\u003eWhile the current study agree with that of Sattayut, 2014 (790 nm, 2 minutes), Jagtap et al.,\u003c/p\u003e \u003cp\u003e2019 (660 nm, 3 minutes) and Ghabraei, S., et al., 2020 (980 nm, 1 minute) in adults [\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e] [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e] [\u003cspan citationid=\"CR17\" class=\"CitationRef\"\u003e17\u003c/span\u003e]. As well as, agree with the study of Shekarchi, F., et al., 2022 (808 nm, 1 minute), U\u0026ccedil;ar, G., \u0026Uuml;. Şermet Elbay, 2022 (810 nm, 20 seconds), and Seraj, Bavaghar et al. 2023 (810 nm, 13 seconds) in children [\u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e] [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e] [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. However, the difference in pain degree between laser group and control group was \u003cb\u003estatistically significant\u003c/b\u003e in only two of those above-mentioned studies, in Jagtap et al., 2019 in adults and U\u0026ccedil;ar, G., \u0026Uuml;. Şermet Elbay, 2022 in children [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e] [\u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e], and it was statistically significant in our study as well.\u003c/p\u003e \u003cp\u003eThus, according to previous results, LLLT diode laser (635 nm; continuous mode; 100 mW; 48.0 J/cm2) decreased pain level of local anesthesia injection with superiority over 20% Benzocaine topical anesthetic gel.\u003c/p\u003e \u003cp\u003eIn this research there was no effect of the order of technique, patient gender, place of injection, and previous dental experiment on pain degree in both methods. As well as; there was no significant difference between positive and absolute positive children in pain degree evaluation of both methods. Unfortunately, there was not any available research about using LLLT in topical anesthesia that studied those variables, so we could not compare our results with similar research. However, maybe we could not find any effect of those variables on pain degree due to choosing only cooperative children.\u003c/p\u003e \u003cp\u003eIt is important to shed light on the positive effect of the basic behavior management techniques, like tell-show‐do, and the distraction impact of the protective glasses were used during LLLT administration, which may affect the assessment of pain degree by the child, and this psychological factor may tip the equation in favor of the laser.\u003c/p\u003e \u003cp\u003eUnfortunately, our sample size was small because it was so difficult to convince parents with safety of LLLT, on the other hand it was not easy to find cooperative children to accept treatment procedure. Thus, we recommend to do further studies with larger sample size.\u003c/p\u003e"},{"header":"Conclusion","content":"\u003cp\u003eAdministration of LLLT diode laser (635 nm) can be considered for decreasing pain of injection in children and it is more effective than 20% Benzocaine topical anesthetic gel, regardless the order of technique, gender, place of injection, previous dental experiment, and behavior assessment. However, further studies are still needed to provide more robust evidence.\u003c/p\u003e "},{"header":"Declarations","content":"\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eAnsam Shafik Alafandy designed the study protocol, and wrote the manuscript text. MHD Abdulrahman MHD Bader Aldin Almourabet performed the in vivo experiments. Ansam Shafik Alafandy and MHD Abdulrahman MHD Bader Aldin Almourabet analyzed the data.\u003c/p\u003e\u003ch2\u003eAcknowledgement\u003c/h2\u003e\u003cp\u003eThe authors thank Dr. Sharif Ashkar, Dr. Hazem Sawaf, Dr. Alaa Homsi and Engineer. Muhannad Abdulmajeed, as well as Dr. Razan Kubaissy, Mr. Shafik Alafandy, Mrs. Aisha Sheikho, for their great support.\u003c/p\u003e\u003ch2\u003eData Availability\u003c/h2\u003e\u003cp\u003eThe datasets analysed during the current study are not publicly available because this research is a part of wider study which has not finished yet, but are available from the corresponding author on reasonable request.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eBaxter, D., \u003cem\u003eLaser acupuncture analgesia: an overview\u003c/em\u003e. Acupuncture in Medicine, 1989. 6(2): p. 57\u0026ndash;60.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eElgadi, R., Y. Sedky, and R. Franzen, \u003cem\u003eThe effectiveness of low-level laser therapy on orthodontic tooth movement: a systematic review\u003c/em\u003e. Lasers in Dental Science, 2023: p. 1\u0026ndash;9.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJagtap, B., et al., \u003cem\u003ePainless injections\u0026ndash;a possibility with low level laser therapy\u003c/em\u003e. J Dent Anesth Pain Med, 2019. 19(3): p. 159\u0026ndash;165.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAnnu, A., et al., \u003cem\u003eComparative evaluation of photobiomodulation therapy at 660 and 810 nm wavelengths on the soft tissue local anesthesia reversal in pediatric dentistry: an in-vivo study\u003c/em\u003e. J Dent Anesth Pain Med, 2023. 23(4): p. 229\u0026ndash;236.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRando, R.G., et al., \u003cem\u003eEffects of Photobiomodulation Using Low-Level Laser Therapy on Alveolar Bone Repair\u003c/em\u003e. Photonics, 2023. 10(7): p. 734.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDipalma, G., et al., \u003cem\u003ePhotobiomodulation and Growth Factors in Dentistry: A Systematic Review\u003c/em\u003e. Photonics, 2023. 10(10): p. 1095.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eStrakas, D. and R. Franzen, \u003cem\u003eThe blue wavelengths in laser dentistry: a review of current literature\u003c/em\u003e. Lasers in Dental Science, 2023. 7(2): p. 97\u0026ndash;99.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eMalcangi, G., et al., \u003cem\u003eTherapeutic and Adverse Effects of Lasers in Dentistry: A Systematic Review\u003c/em\u003e. Photonics, 2023. 10(6): p. 650.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHilgers, J.J. and S.G. Tracey, \u003cem\u003eClinical uses of diode lasers in orthodontics\u003c/em\u003e. Journal of clinical orthodontics: JCO, 2004. 38(5): p. 266\u0026ndash;273.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eEl-Qashty, R., O.A. Elkashty, and E. Hany, \u003cem\u003eTherapeutic Potential of Low-Level Laser Photobiomodulation on Adjuvant Induced Temporomandibular Joint Arthritis in A Rat Model\u003c/em\u003e. Mansoura Journal of Dentistry, 2023. 10(1): p. 1\u0026ndash;8.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eSun, G. and J. Tun\u0026eacute;r, \u003cem\u003eLow-level laser therapy in dentistry.\u003c/em\u003e Dent Clin North Am, 2004. 48(4): p. 1061-76, viii.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eDeana, N.F., et al., \u003cem\u003eEffectiveness of Low-Level Laser Therapy in Reducing Orthodontic Pain: A Systematic Review and Meta-Analysis.\u003c/em\u003e Pain Res Manag, 2017. 2017: p. 8560652.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAhmad, S.A., et al., \u003cem\u003eLow-level laser therapy in temporomandibular joint disorders: a systematic review\u003c/em\u003e. J Med Life, 2021. 14(2): p. 148\u0026ndash;164.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eHashemi, I.S.E., et al., \u003cem\u003eEffects of Diode Low-Level Laser Therapy of 810 Nm on Pulpal Anesthesia of Maxillary Premolars: A Double-Blind Randomized Clinical Trial\u003c/em\u003e. European Endodontic Journal, 2021. 6(2): p. 155.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eRen, C., C. McGrath, and Y. Yang, \u003cem\u003eThe effectiveness of low-level diode laser therapy on orthodontic pain management: a systematic review and meta-analysis\u003c/em\u003e. Lasers in Medical Science, 2015. 30(7): p. 1881\u0026ndash;1893.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eWu, S., et al., \u003cem\u003eEffect of low-level laser therapy on tooth-related pain and somatosensory function evoked by orthodontic treatment\u003c/em\u003e. International Journal of Oral Science, 2018. 10(3): p. 22.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eAhrari, F., et al., \u003cem\u003eThe efficacy of low-level laser therapy for the treatment of myogenous temporomandibular joint disorder\u003c/em\u003e. Lasers Med Sci, 2014. 29(2): p. 551\u0026ndash;7.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eJagtap, B., et al., \u003cem\u003ePainless injections-a possibility with low level laser therapy\u003c/em\u003e. J Dent Anesth Pain Med, 2019. 19(3): p. 159\u0026ndash;165.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eU\u0026ccedil;ar, G., \u0026Uuml;. Şermet Elbay, and M. Elbay, \u003cem\u003eEffects of low level laser therapy on injection pain and anesthesia efficacy during local anesthesia in children: A randomized clinical trial\u003c/em\u003e. Int J Paediatr Dent, 2022. 32(4): p. 576\u0026ndash;584.\u003c/span\u003e\u003c/li\u003e \u003cli\u003e\u003cspan\u003eNarayan, V. and S. Samuel, \u003cem\u003eAppropriateness of various behavior rating scales used in pediatric dentistry: A Review\u003c/em\u003e. J Global Oral Health, 2019. 2(2): p. 112\u0026ndash;7.\u003c/span\u003e\u003c/li\u003e\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":"Anesthesia, low- level laser, pain, topical","lastPublishedDoi":"10.21203/rs.3.rs-4243790/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-4243790/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cstrong\u003eAim\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe aim of this study was to evaluate the efficacy of low-level laser therapy (LLLT) in reducing the pain of needle injection during local anesthesia in children.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eMaterials and Methods\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eTwenty cooperative healthy kids participated in this research; their ages were between 8-12 years old. In laser group (LG) LLLT diode laser (635 nm; continuous mode; 100 mW; 48.0 J/cm\u003csup\u003e2\u003c/sup\u003e) was applied buccally in one side of the mandibula or maxilla in contact with the soft tissue for 120 second. While in the contralateral side 20% Benzocaine Gel topical anesthetic was applied for the same time and this was the control group (CG). Then a short needle was inserted in each side and the pain was evaluated for each side separately using the Wong-Baker Faces Pain Rating Scale (PRS).\u003c/p\u003e\n\u003cp\u003eNon-parametric analysis was applied and data were analyzed for statistical significance (p \u0026lt; 0.05).\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eResults\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe total cases were twenty, (10 in the maxilla and 10 in the mandible). The \"no pain\" and \"severe pain\" rates in the PRS were 41.7% and 3.3% for the LG and 21.7% and 11.7% for the CG, respectively, during injection. The mean pain degree was 2.6 in CG while it was 1.2 in LG. Wilcoxon analysis revealed a statistically significant difference between LG and CG (P=0.001\u0026lt;0.05). \u0026nbsp;While there was no significant difference in evaluating pain degree according to the order of technique, gender, place of injection, previous dental experiment, and behavior assessment in both methods.\u0026nbsp;\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConclusion\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eAdministration of LLLT diode laser (635 nm) can be considered for decreasing pain of injection in children and it is more effective than 20% Benzocaine topical anesthetic gel, regardless the order of technique, gender, place of injection, previous dental experiment, and behavior assessment.\u0026nbsp;\u0026nbsp;\u003c/p\u003e","manuscriptTitle":"Evaluating the effectiveness of low-level laser therapy in reducing local anesthesia injection pain in children","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2024-06-03 14:38:36","doi":"10.21203/rs.3.rs-4243790/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":"333f966d-7640-4e55-b520-ac453ae20575","owner":[],"postedDate":"June 3rd, 2024","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"posted","subjectAreas":[{"id":32469045,"name":"Health sciences/Health care"},{"id":32469046,"name":"Health sciences/Medical research"}],"tags":[],"updatedAt":"2024-06-04T11:33:02+00:00","versionOfRecord":[],"versionCreatedAt":"2024-06-03 14:38:36","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-4243790","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-4243790","identity":"rs-4243790","version":["v1"]},"buildId":"qtupq5eGEP_6zYnWcrvyt","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}