In Vitro Investigation of the Effect of Different Surface Pretreatments, Materials, and Bonding Systems on Shear Strength in the Repair of Restorations

Aim The purpose of our study is to investigate the adhesive strength of commonly used ceramics in clinics with different surface treatments and using dental materials for repairs Material and method Our study was conducted on 16 experimental groups, each comprising 7 test specimens. The experimental group specimens consisted of restoration material, adhesive system, and repair material, resembling a restoration repair application. The Vita VMK 95 slated for repair was utilized. Surface pretreatment included roughening with a bur, application of hydrofluoric acid, and silanization process. As for the repair material, composite, flowable composite, compomer, and flowable compomer were employed. To facilitate the bonding of the repair material to the restoration material, or total-etch and self-etch systems were applied. Following the completion of restoration and repair procedures, the test specimens were affixed to a Shimadzu Autograph AG-X (Shimadzu Corp., Japan) universal testing machine to measure their shear bond strengths. The evaluation of measurement results related to Kruskal-Wallis test for inter-group comparisons and Dunn's multiple comparison test for subgroup comparisons. The results were assessed at a significance level of P < 0.05, with a confidence interval of 95%. Results TAll groups prepared with hydrofluoric acid and silanization (14,996±2,756) exhibited higher shear bond strength compared to all groups prepared with bur roughening (8,378±0,795). Conclusion In the repair of ceramic restorations, the application of hydrofluoric acid and silan to the surface should be preferred over surface roughening with a bur in terms of shear bond strength.