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

OBJECTIVE: 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. MATERIALS AND METHODS: 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). RESULTS: 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. CONCLUSIONS: 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.

Influence of Sapindus mukorossi extract in comparison to 17% EDTA as final root canal irrigant on the sealer penetration and microleakage of dentinal tubules.

OBJECTIVE: The study evaluated the effect of Sapindus mukorossi (SM) extract as a final root canal irrigant on sealer penetration (SP) in dentinal tubules and microleakage. MATERIALS AND METHODS: Samples were selected based on inclusion and exclusion criteria. An access opening in all samples was performed and the working length was decided using pro taper for canal finishing along with constant irrigation. Specimens were randomly divided into 3 groups. Group 1 was irrigated with 3 ml of 17% EDTA; group 2 was irrigated with SM irrigant and group 3 samples were irrigated with 0.9% saline. After obturation, samples were vertically placed in 1% methylene blue dye cut in half longitudinally, and viewed under a stereomicroscope. Analysis of SP in the dentinal tubule was assessed using scanning electron microscopy (SEM). For microleakage assessment, mean and standard deviation were reported and One-Way ANOVA was applied. SP was compared using Kruskal-Wallis' test. For inspecting the interaction between SM/EDTA and NaOCl, Fisher's exact test was applied. No statistically significant difference between microleakage in any of the tested groups was observed. The control group showed minimum leakage as compared to EDTA and SM. RESULTS: The results displayed that there was no significant difference, (p=0.67), between dentinal tubule SP at 2 mm. A significant difference between dentinal tubule SP among groups at 5 mm was observed (p<0.05). CONCLUSIONS: SM ethanolic extract showed comparable outcomes of smear layer removal and sealer penetration to 17% EDTA, as a final irrigant in root canal cleaning. Therefore, SM has the potential to be used as an adjuvant final irrigant in conjunction with NaOCl.