Evaluation of Shear Bond Strength of Stainless Steel Brackets Bonded to Ceramic Crowns Etched with Er; Cr: YSGG Laser and Hydrofluoric Acid: An In vitro Study

Aim: This in vitro study was designed to evaluate and compare the shear bond strength of stainless steel brackets bonded to ceramic crowns etched with Hydrofluoric acid and Lasers.
Place of Study: This study was carried out in the Department of Orthodontics and Dentofacial Orthopedics, RMDCH, Annamalai University, Chidambaram, 2012 to 2014.
Methodology: Forty ceramic crowns were fabricated using Vita ceramic blocks and were mounted on acrylic blocks. Samples were randomly divided into four groups and stored in artificial saliva. Ceramic surfaces from Group A and B were etched with 4% hydrofluoric acid and Group C and D were etched with Lasers respectively and they were bonded to stainless steel brackets. Samples from group A and C were bonded with stainless steel brackets using light cure GIC and samples from group B and D were bonded with stainless steel brackets using light cure composite. Debonding of the brackets from ceramic surface was carried out using universal testing machine and the debonded surface texture was analysed using SEM.
Results: Both mean values and standard deviations were estimated from the sample for each study group. Mean values of shear bond strengths were compared by using one- way ANOVA followed by Tukey-HSD procedure. Pearson chi-square test was done to test the significance of shear bond strength between study groups. Mean shear bond strength in Group D (9.23±2.74 Mpa) was significantly higher than remaining tested groups followed by Group B (7.5±1.029 Mpa), Group C(6.823±1.202 Mpa) and Group A (6.11±1.019 Mpa) (p< 0. 05).
Conclusion: Er-Cr: YSGG laser etching on roughened ceramic can be used as an alternative for bonding orthodontic attachments to ceramic surfaces.