Antimicrobial photodynamic therapy as an adjunct for management of deep caries lesions - Study protocol for a randomized, controlled clinical trial

Abstract Background: Alternatively to conventional treatments, chemo-mechanical caries removal agents can be used. A modality of treatment that has been increasing in dentistry is antimicrobial photodynamic therapy (aPDT). Bixa orellana, is being researched for application in aPDT. This protocol aims to determine the effectiveness of aPDT with Bixa orellana extract in deep caries lesions.Methods: A total of 160 teeth with deep occlusal dental caries will be selected and divided in 3 groups: G1 - control group (Caries removal with a lowspeed drill); G2 - Partial Caries Removal with Papacarie; G3 - Partial Caries Removal with Papacarie and application Bixa orellana extract (20%); G4 - Partial Caries Removal with Papacarie and application Bixa orellana extract (20%) with LED (aPDT). After treatment, all the teeth will be restored with glass ionomer cement and followed up clinically and radiographically, with evaluations at immediately, 1 week, 1, 3, 6, and 12 months. Dentin samples before and after treatment will be analyzed microbiologically. The data will be submitted to descriptive statistical analysis of the association between the categorical variables using the chi-square test and Fisher exact text. The Student t test and analysis of variance will be used for the comparison of mean signs and symptoms of reversible pulpitis. Pearson correlation coefficients will be calculated for the analysis of correlations among the continuous variables.Discussion: Procedures using aPDT have been developed for the treatment of dental caries, but, there are few controlled clinical trials in the literature confirming its efficacy.Trial registration: This protocol is registered at ClinicalTrials.gov under the number NCT05236205 and it was first posted on 01/21/2022 and last updated on 05/10/2022, https://clinicaltrials.gov/ct2/show/NCT05236205?term=NCT05236205&draw=2&rank=1.