Comparison of Adhesive Bond Strength between a Tooth with a Self-Ligating and a Ligature Brackets in vitro

Objective. To study the micromechanical bonding of brackets to the enamel surface under laboratory conditions using the fifth-generation composite «CompoFix Ortho» (Vladmiva, Russia) in comparison with the adhesive «Transbond XT» (USA), taking into account the bond strength to self-ligating and ligature brackets. Materials and methods. To study the bond strength of brackets with samples consisting of 20 teeth (premolars) extracted for orthodontic indications without caries lesions, randomly divided into two groups of 10 teeth with direct bonding of brackets. Group 1 used self-ligating brackets, while Group 2 used ligature brackets. In both groups, the bond strength of the bracket to the enamel was studied with two types of adhesives: the adhesive and primer of the 5th generation composite «CompoFix Ortho» (RF) in comparison with «Transbond XT» (USA) with Orthos composite. Samples were tested for the presence of adhesive residues using the Adhesive Residue Index (ARI) scale. Results. The average adhesive bond strength when detaching metal brackets from tooth enamel using the composite «CompoFix (Ortho)» (RF) and its foreign analogue «Transbond XT» (USA) was 7.6 ± 0.3 MPa (P ≥ 0.05), but statistically differed (P ≤ 0.05) between self-ligating (7.8 ± 0.3 MPa) and ligature brackets (7.1 ± 0.15 MPa). Conclusion. The results of experimental studies demonstrate that the fifth-generation domestic adhesive complex «CompoFix (Ortho)» can be recommended for use in orthodontic practice for bonding metal brackets with two types of ligations to tooth enamel. The Adhesive Residue Index (ARI) showed a uniform adhesive bond between the metal bracket, the adhesive layer, and the enamel. Adhesion failure occurs uniformly between the adhesive layer and the metal bracket and the adhesive layer and the enamel when using the domestic adhesive complex and its foreign equivalent.