Abstract
Introduction
The bond strength of metal brackets to dental restorations directly affects the success of orthodontic treatment. In recent years, the clinical use of permanent restorations for adult patients and fabricated using three-dimensional (3D) printers has been increasing. Therefore, the present study aims to evaluate the shear bond strength (SBS) between orthodontic metal brackets and three different permanent restorative resins.
Methods
A total of 120 central incisor-shaped samples (n=40 per group) were fabricated from three different permanent restoration resins using a 3D printer: Saremco Print Crowntec (CR), VarseoSmile Crown Plus (VS), and P-Crown V3 (PC). The samples were polished, and the surface area for bracket bonding was roughened under standardised conditions using Al2O3 sandblasting. Following cleaning, metal brackets were bonded using a bis-acryl composite resin according to the adhesive protocol. To simulate intraoral conditions, all samples underwent thermocycling (10,000 cycles between 5°C - 55°C), followed by bond strength testing using a universal testing machine. SBS values and the Adhesive Remnant Index (ARI) scores were recorded. ANOVA was performed to assess the effect of the different resin types on SBS. A Fisher–Freeman–Halton exact test was applied for the comparison of ARI scores.
Results
The mean and standard deviation of SBS values were 13.28 ± 2.85 MPa for the CR group, 13.92 ± 1.60 MPa for the VS group, and 13.33 ± 2.75 MPa for the PC group. Statistical analysis using the ANOVA test revealed no significant differences between the three resin groups (p = 0.738). In the comparison of the ARI scores between the different resin types, no statistically significant differences were observed (p >0.05).
Conclusions
The bond strength values between permanent restorative resins and metal brackets were found to be clinically acceptable, and the structural differences between the resins did not affect bond strength.