To critically investigate the long-term adhesive integrity and shear bond performance of zirconia when luted with Calibra and RelyX 200 self-adhesive resin cements, emphasizing the effects of hydrolytic aging on bond durability and clinical longevity

Introduction: Zirconia is widely used in dental restorations for its strength and aesthetics. Bonding it to resin cements is challenging; this study evaluates SBS using two self-adhesive cements. Aim: To critically investigate the long-term adhesive integrity and shear bond performance of zirconia when luted with Calibra and RelyX 200 self-adhesive resin cements, emphasizing the effects of hydrolytic aging on bond durability and clinical longevity. Materials and Methods: Sixty CAD/CAM zirconia samples were divided into two groups: Calibra and RelyX 200. Samples were bonded and aged in distilled water before SBS testing with a Universal Testing Machine. Introductory lab-based in-vitro study in Ghaziabad and Noida. Testing was done using a standardized Universal Testing Machine setup. 60 zirconia blocks (10 mm × 5 mm) fabricated via CAD/CAM. Grouped into Calibra (A) and RelyX 200 (B); all stored in distilled water. UTM applied shear force at 0.5 mm/min until bond failure. Maximum load was measured and converted to MPa. Data Analysis: SBS in MPa calculated; statistical tests (ANOVA, t-test) applied. Significance set at p < 0.05; power analysis done via G*Power. Ethical Approval: Approved by institutional ethical committee (Ref: SBBDC/2023/382). Approval date: 15/05/2023. Results: SBS peaked at 24 hours and declined slightly at 72 hours. RelyX 200 showed higher stability, but differences were statistically insignificant. Conclusion: Calibra showed stronger initial bonding; RelyX 200 performed better long-term. Both cements are clinically viable for zirconia bonding in prosthodontics. Key Words: CAD/CAM technology, Self-adhesive cements, Shear bond strength test, Universal Testing Machine, Zirconia