ORTHODONTIC BRACKETS’ SHEAR BOND STRENGTHS AFTER APPLYING REMINERALIZING AGENTS

YUSUF ÖZANT, YAZGI AY ÜNÜVAR

International Dental Research - 2021;11(2):67-74

Aydın Adnan Menderes University, Faculty of Dentistry, Department of Orthodontics, Aydın, Turkey

 

Aim: The aim of this in vitro study was to measure the effects of white spot lesions treatment agents on the shear bond strengths (SBSs) and adhesive residual indexes (ARIs) of orthodontic brackets. Methodology: This study used 100 human premolar teeth randomly divided into five groups. Group 1 comprised those with intact enamel, Group 2 comprised those with demineralized enamel and Groups 3–5 comprised those demineralized enamel that was treated with casein phosphopeptide amorphous calcium phosphate fluoride (CPP-ACPF), fluoride varnish and a resin infiltrant, respectively. Brackets were bonded to the teeth using the conventional method, then the samples were thermocycled and tested for SBS using a universal testing machine. The adhesive remnant indexes (ARI) of the brackets were also evaluated. One-way ANOVA and post-hoc Tukey tests were used to compare the groups’ SBSs and the Kruskal–Wallis test was used to evaluate the groups’ ARI scores. Results were considered statistically significant if p was less than 0.05. Results: Statistically significant differences were found between the groups (F was 6.895 and p was less than 0.001). The SBSs of the brackets in Group 4 were significantly lower than those of the other groups (the mean was 13.44 ± 6.37 MPa). Group 5 had the highest mean SBS value (22.11 ± 6.56 MPa). Additionally, the ARI scores of the four groups were significantly different (p was less than 0.001). Conclusion: Resin infiltration and CPP-ACPF applications can improve bonds to demineralized enamel, while fluoride varnish applications are not recommended for such enamel.