Comparison of shear bond strength of orthodontic brackets bonded to natural teeth, stainless steel crowns and ceramic crowns: An in-vitro study

Introduction:The increasing prevalence of adult patients with diverse dental restorations poses a significant challenge in orthodontics, particularly in accurately assessing bond strength across various surfaces.The presence of metal and ceramic crowns, along with natural teeth, complicates the bonding process, as each material interacts differently with orthodontic adhesives.Understanding these differences is crucial for clinicians to select the most appropriate bonding approach, ensuring sustained bracket positioning, reducing treatment duration, and improving overall treatment outcomes for patients with mixed dental restorations.Objective: This study evaluates and compares the shear bond strength (SBS) of metal and ceramic brackets on 3 different surfaces viz.natural teeth, metal crown and ceramic crown. Materials and Methods:In this in-vitro study, 90 samples were prepared.They were divided into 3 groups -30 samples in each group based on 3 different surfaces-natural teeth, metal crown and ceramic crown.For each group 15 metal and 15 ceramic brackets were bonded with same adhesive material.The debonding force was applied using universal testing machine for all the samples in a standardized condition.ANOVA test along with Tukey's posthoc test were performed to test the significance of SBS difference between metal and ceramic bracket on various surfaces.All tests were based on p≤0.005 as probability of error.Results: The SBS of metal brackets on natural teeth (9.31MPa) and ceramic crown (6.94MPa) is adequate, as compared to metal crown (4.84MPa).The SBS of ceramic brackets on natural teeth (11.58MPa) and metal crown (11.44MPa) is significantly high.Conclusion: The bond strength of ceramic brackets was found to be greater on metal crowns compared to metal brackets, an unexpected result that underscores a significant finding.The shear bond strength of ceramic brackets was greater on all surfaces when compared to metal brackets.