FATIGUE BEHAVIOR OF OCCLUSAL VENEER TO RESTORE CRACKED VITAL TEETH

Objectives: This study evaluates the cyclic fatigue resistance of hybrid ceramic and lithium disilicate materials, cemented with two different cements on a simulated vital cracked tooth. Materials and Methods: Forty dentinal analogues were prepared, with standardized cracks in 20 samples. Hybrid ceramic and lithium disilicate crowns were fabricated and cemented using Panavia SA Plus and VisCalor Bulk cements. Optical Coherence Tomography (OCT) measured initial crack lengths, followed by an accelerated fatigue test. Statistical analysis included three-way ANOVA and post-hoc Bonferroni tests. Results: Panavia-cemented groups exhibited significantly more material cracks (p < 0.01). Initial cracks in the dentin substrate significantly increased fracture lines in restorative materials (p = 0.006). No significant differences were found between the two restorative materials. Conclusions: Both Vita Enamic and IPS e.max CAD are suitable for occlusal veneers. VisCalor Bulk is more effective than Panavia SA in the presence of substrate cracks. Substrate cracks reduce fracture resistance in restorative materials. Further studies are needed to confirm these findings.