Abstract :
Purpose: The purpose of this study is to compare the shear bond strength of metallic orthodontic brackets bonded to zirconium surfaces by using various surface preparation methods and also with application of different adhesive primers and to determine which prime r is more effective on prepared zirconium surfaces.
Materials and Methods:Twenty seven zirconia blocks with 90 zirconium surfaces were divided into three groups of 30 surfaces each; group 1(9.6% Hydrofluoric acid, HF), group 2 (Sandblasting, SB) and group 3 (Sandblasting Hydrofluoric acid i.e., SHF). Each group was separated into three subgroupsof ten surfaces each;(a) Silaneprimer, (b) Bisphenol A Diglycidylether Dimethacrylate (Bis -GMA)primer and (c) Silane 10-methacryloyloxydecyl dihydrogen phosphate (SMDP) primer. After surface treatment, Maxillary central incisor metal brackets were bonded with light cure composite to zirconium surfaces. The shear bond strength values were measured by a universal testing machine with a crosshead speed of 1 mm/min. The data was analyzed using one-way ANOVA and Post hoc tests.
Results: Highest shear bond strength was observed in SHF group with SMDP primer (14.50 ± 0.7 MPa) and the lowest shear bond strength was observed in HF group with Silane primer (4.60 ± 0.9 MPa). The results showed that there was a statistical significant difference between all groups (p< 0>
Conclusion: Therefore, it can be concluded that the combination of Sandblasting and Hydrofluoric acid surface preparation with application of Silane 10-methacryloyloxydecyl dihydrogen phosphate primer is a suitable choice for bonding a metal bracket to zirconium crown.
Keyword :
Shear bond strength, Metal brackets, Zirconia, Hydrofluoric acid, Sandblasting,
Silane primer, Bis-GMA primer, SMDP primer.