Comparative evaluation of the fracture resistance of endodontically treated premolars after different access cavity designs-root canal taper combinations

Abstract

Purpose: This research compared the fracture resistance of endodontically treated premolars with traditional and conservative access cavity designs and different root canal tapers (0.04 and 0.07). Materials and methods: In the current study, ninety extracted human mature intact maxillary first premolars with comparable sizes were chosen. The teeth were randomly assigned into seven groups, one control group (n =30) and six test groups (n=10 each) according to the access cavity design and instrumentation system, Group 1 (control group): Intact teeth with no treatment, Group 2: Teeth with prepared TAC with no instrumentation, Group 3: Teeth with prepared CAC with no instrumentation, Group 4: Traditional access cavity/ Primary WaveOne gold, Group 5: Traditional access cavity/ XP‑Endo Shaper, Group 6: Conservative access cavity/ Primary WaveOne gold, and Group 7: Conservative access cavity/ XP‑Endo Shaper. Filling of the root canals was done using gutta-percha/Endosequence BC sealer in lateral condensation technique. The force required to fracture each tooth was measured and recorded in Newtons by loading it in the universal testing machine until fracture occurred. Analysis of fracture resistance data was done using Two-Way ANOVA test, followed by Tukey test for multiple pairwise comparisons. Differences among groups were considered significant if p-value ≤0.05. Results: The control group had the highest fracture resistance while group 4 (Traditional access cavity/WaveOne gold) recorded the lowest value. The difference among the groups was statistically significant (P < .05). Conclusions: Endodontically treated maxillary premolars show significantly reduced fracture resistance when prepared with greater taper instruments, regardless of their access cavity design. KEYWORDS: Conservative access cavity, endodontically resistance, root canal taper, traditional access cavity.