Comparative Evaluation of Different Endodontic Access Cavity Designs with Different Burs—An in vitro Experimental Insight into the Aspect of Fracture Resistance

Abstract

Introduction: In vitro fracture resistance of extracted mandibular molars treated with various access cavity designs, including traditional endodontic cavity (TradAC), conservative/contracted endodontic cavity (ConsAC), ninja endodontic cavity (UltraAC), truss endodontic cavity (TrussAC), caries‑driven access cavity (CariesAC), and intact teeth, is the focus of this study. Materials and Methods: Six groups of 20 mandibular molars, totaling 120, were used in the investigation. While the other five groups underwent various access cavity preparations, chemomechanical preparation, and obturation procedures before being repaired with composite resin, Group 1 was left unaltered (the control). A 6 mm round head tip was used to apply the fracture force, which was measured in newtons, at a crosshead speed of 1 mm/min until fracture developed. Results: According to the current study, the intact control group had the maximum fracture resistance. The access cavity groups’ mean values were maximum in CariesAC followed by ConsAC, TrussAC, UltraAC, and TraditonalAC respectively. Conclusion: While among the four minimally invasive designs, CariesAC showed a higher fracture resistance despite the results being statistically insignificant, TradAC had a significantly lower resistance than other conservative access cavity designs.