COMPARSION OF THE SHEAR BOND STRENGTH OF CERAMIC BRACKETS BONDED TO PORCELAIN FUSED METAL CROWNS AND METAL FREE CERAMIC CROWNS WITH AND WITHOUT SILANE COUPLING AGENT- AN IN VITRO STUDY.

Abstract

Aim-The aim of this study is to evaluate and compare the shear bond strength of ceramic brackets bonded to porcelain fused metal crowns and metal free ceramic crowns with and without silane coupling agent.Material and Method: 40 metal free zirconia crowns and 40 PFM crowns were fabricated with glazed surfaces according to the manufacturer's instructions for the study purpose.The samples were divided in two groups A and B and each group was subdivided into two subgroups (A1, A2) and (B1, B2) Sub-Group A1 and A2: Twenty metal free ceramic crowns were etched with 9% buffered HF acid gel for 2 minutes,thoroughly washed and air dried.Relyx ceramic primer (silane coupling agent) was applied to the treated surface.Subgroup B1 and B2: 20 porcelain fused metal crowns were etched with 9% buffered HF acid gel for 2 minutes,thoroughly washed and air dried.Relyx ceramic primer (silane coupling agent) was applied to the treated surface. The shear bond strength of ceramic brackets bonded to porcelain fused metal crowns and metal free ceramic crowns with and without silane coupling agent. Statistical Analysis: ANOVA and Post hoc Tukey's test (HSD) tests were used for statistical analysis. Result: The result showed that group B1 demonstrate the maximum shear bond strength among all groups which is 9%HF +Relyx ceramic primer application on porcelain fused metal crowns (10.27+1.31Mpa) and has highly significant value.Whereas lowest shear bond strength belongs to group B2which is 9%HF and primer is not applied(5.4+0.73 Mpa).Conclusion: Hence it can be concluded that Relyx ceramic primer is more apropriate choice for bonding orthodontic metal brackets on PFM and zirconia surfaces with conventional bonding system.