Photodynamic therapy on the extrusion bond strength of gutta-percha to radicular dentin sealed with bioceramic and conventional sealers.

Abstract

The aim of this study was to evaluate the influence of photodynamic therapy (PDT) on the extrusion bond strength (EBS) of gutta-percha to radicular dentin sealed with bioceramic sealers. Sixty human-extracted mandibular premolars were used in the present study, being decoronated up to the cementoenamel junction, and secured in heat cure acrylic resin for root canal therapy. The specimens were randomly divided into groups based on conventional [2.25% sodium hypochlorite (NaOCl) + 17% EDTA] and disinfection protocols (2.25% NaOCl + PDT + 17% EDTA) (n = 10). Specimens in groups 1, 3, 5: conventional treatment modality (2.25% NaOCl + 17% EDTA). Samples in groups 2, 4, 6: adjunctive PDT treatment modality (2.25% NaOCl+ PDT+ 17% EDTA). Specimens in groups 1 and 2 were sealed with AH Plus sealer (AH). Specimens in groups 3 and 4 were sealed using Endo Sequence BC sealer, and samples in groups 5 and 6 were sealed with MTA Fillapex. All specimens were cut in the coronal and middle segments and positioned in a universal testing machine (UTM) for assessment of extrusion bond strength (EBS). ANOVA and Post-Hoc Tukey multiple comparison tests were applied for performing statistical analysis (p < 0.05). Coronal root samples in group 1 (2.25% NaOCl + 17% EDTA) sealed with AH Plus sealer demonstrated the highest EBS value (9.21 ± 0.62 MPa) whereas the middle-third of specimens in group 6 (2.25% NaOCl + PDT + 17% EDTA) sealed with MTA Fillapex exhibited the lowest EBS value (5.07 ± 0.17 MPa). Intergroup comparison revealed that group 3 (2.25% NaOCl + 17% EDTA) sealed with Endo Sequence BC Sealer and group 5 (2.25% NaOCl + 17% EDTA) sealed with MTA Fillapex disclosed comparable EBS results to group 1 (p > 0.05) while group 2 (2.25% NaOCl + PDT + 17% EDTA) sealed with AH Plus sealer and group 4 (2.25% NaOCl + PDT + 17% EDTA) sealed with Endo Sequence BC Sealer unveiled analogous EBS values to group 6 (2.25% NaOCl + PDT + 17% EDTA) MTA Fillapex (p > 0.05). The most noticeable failure mode in the coronal and middle thirds of non-PDT subjected groups was cohesive. Combination of 2.25% NaOCl with PDT and 17% EDTA for canal disinfection with AH Plus sealer, calcium silicate sealer, and MTA-based bioceramic sealers have an unfavorable effect on the EBS of gutta-percha to the root canal wall.