Influence of Access Cavity Design on the Fracture Strength of Endodontically Treated Teeth Restored Using Short Fiber-Reinforced Composite and High Strength Posterior Glass Ionomer Cement

Aim: This in vitro study aimed to determine the influence of access cavity design and residual tooth structure and to compare the fracture resistance of the teeth post endodontically restored with short fiber-reinforced composite (GC everX Posterior; GC, India) and conventional posterior high-strength GIC (Glass Ionomer Cement) (GC Gold Label IX; GC, India). Methods: Ninety extracted human mandibular molars were classified into five groups, i.e., one control group (n = 10) and four test groups based on the access cavity design (n = 20): Traditional access cavity (TAC), Conservative access cavity (CAC), Ninja access cavity (NAC), and Truss access cavity (TRAC). Then 80 teeth in test groups were endodontically treated and further subdivided (n = 10) based on post-endodontic restorative materials, i.e., short fiber-reinforced composite (SFC) and Type 9 GIC. Samples were then subjected to fracture resistance under a universal testing machine and fracture loads were compared statistically. Results: The fracture resistance of various access cavity designs (TAC, CAC, NAC, and TRAC) varied significantly (P < .05). Regardless of access cavity design, teeth restored with SFC had higher fracture resistance than teeth restored with high strength posterior GIC (P = .001). Conclusion: Using newer access cavity designs like (CAC, NAC, and TRAC) and reinforcing the teeth with a post-endodontic restoration such as SFC, fracture resistance of endodontically treated teeth can be improved notably.