FRACTURE RESISTANCE OF ENDOCROWNS FABRICATED FROM THREE DIFFERENT PRESSABLE CERAMIC MATERIALS

Introduction: The selection of fabrication materials plays a crucial role in the clinical outcome of endocrown restorations. However, a notable gap exists in understanding the biomechanical implications of certain materials for endocrown restorations.Purpose: The aim of the study was to evaluate and compare the fracture resistance of endocrowns fabricated from three different pressable ceramic materials.Materials and Methods: Extracted non carious mandibular first molar was embedded in acrylic resin cylinder then prepared to receive an endocrown. Thirty positive replica of epoxy resin dies were used. The dies were randomly divided into three groups (n=10): restored using zirconia reinforced lithium disilicate and zirconia reinforced lithium silicate and lithium disilicate. After cementation, the fabricated endocrowns were exposed to thermal and cyclic loading corresponding to six months of clinical service to simulate oral cavity conditions. Each endocrown was tested under a compressive load using a universal testing machine to evaluate the fracture resistance. Failure mode analysis was evaluated visually. Data was collected and analyzed using Kruskal-Wallis test and Dunn- Sidak test.Results: The highest mean and median Fracture Resistance (N) were observed in the e-max group (2289.32 and 2178.36 respectively), followed by the Celtra press group (2236.03 and 2093.52 respectively). The lowest Fracture resistance was observed in Vita Ambria group with a mean of 2014.40 and a median 1908.59. However, all values were within the acceptable clinical range. (p=0.155). Conclusion: No significant difference in fracture resistance among endocrowns fabricated from lithium disilicate ceramic, zirconia-reinforced lithium silicate, and zirconia-reinforced lithium disilicate.