Comparison of Shear Bond Strength and Adhesive Remnant Score of Orthodontic Brackets Bonded with Three Different Orthodontic Adhesives: An In-vitro Study

Abstract

Introduction: Adequate bond strength between orthodontic brackets and enamel is necessary to withstand masticatory forces. Priming involves applying a primer before using the adhesive as a separate step. To reduce bonding time, manufacturers have introduced self-priming adhesives. Aim: To evaluate the Shear Bond Strength (SBS) and Adhesive Remnant Index (ARI) scores of a Bis-GMA based self-priming adhesive (Orthofix SPA, Anabond) and compare it with a 2-Hydroxyethyl Methacrylate (HEMA) based self-priming adhesive (Aqualine LC, Tomy ortho) and a Bis-GMA containing primer-based orthodontic adhesive (Transbond XT, 3M). Materials and Methods: The present In-vitro study was conducted at the White Lab., Saveetha Dental College and Hospitals, Chennai, Tamil Nadu, India, from December 2020 to January 2021. A total 54 freshly extracted premolar teeth were collected and divided into three groups (Group A - Orthofix SPA, Group B - Transbond XT, and Group C - Aqualine LC) based on the adhesive used. A 0.022 metal orthodontic brackets were bonded, and SBS and ARI scores of the samples were assessed. The Shapiro-Wilk test for normality was conducted. One-way Analysis of Variance (ANOVA) was used to compare the mean and standard deviation of SBS values and ARI scores among the three groups, and a post-hoc Tukey test was performed for inter group comparisons. Results: Significant inter group differences were observed (p=0.004). Group A had lower SBS than Groups B and C. Significant inter group differences (p-value of 0.003) in ARI scores were noted, with Group A having the lowest scores. Conclusion: The Bis-GMA self-priming adhesive (Orthofix SPA) exhibited lower SBS and ARI scores compared to commercially available HEMA-based self-priming adhesive systems and primer-based Bis-GMA adhesive systems.