Effect of laser-assisted retrograde cavity preparation on push-out-bond-strength of mineral trioxide aggregate and calcium-enriched-mixture-cement

Abstract

Objective: This study aimed to determine the push-out-bond-strength(PBS) of mineral trioxide aggregate(BIOMTA+) and calcium-enriched-mixture-cement (CEM) in retrograde cavities prepared using Er: YAG laserand stainless-steel bur. Material and Methods: The root canals of 60 extracted single-rooted human teeth wereprepared, filled and their apical portion of 3-mm were resected using a diamond bur and randomly dividedinto four groups according to technique of retrograde preparation and filling material as follows(n=15):Group1: bur/ BIOMTA+ ,Group2: bur/ CEM, Group3: Er:YAG laser/ BIOMTA+, Group4: Er:YAG laser/ CEM.PBS test were performed to specimens and failure modes were evaluated. The data were statistically analyzedwith ANOVA, Post-Hoc Tukey and t tests (p< 0.05). Results: CEM was exhibited higher than bond strengthcompared to BIOMTA+ in retrograde cavity prepared using laser (p= 0.021) and BIOMTA+ in retrograde cavityprepared using bur was exhibited higher than bond strength compared to in retrograde cavities prepared usinglaser (p= 0.024). Failure modes were dominantly cohesive in all groups tested and one representative specimeneach failure mode was examined in SEM and the general characteristics of the failure modes were confirmed.Conclusion: With in the limitations of the present study, when used CEM, Er: YAG laser-assisted retrogradecavity preparation positively affected the bond strength values compared to BIO MTA+. Considering its optimaladhesion, the calcium-enriched-mixture-cement (CEM) might be a good option as a filling material in retrogradecavities in clinical use.KEYWORDSCalcium-Enriched-Mixture-Cement (CEM); Er: YAG laser; Mineral trioxide aggregate; Retrograde cavity preparation.