Evaluation of the effect of different primer and colouring solutions in the orthodontic bonding process

Objective: This in vitro study evaluated the effect of different colouring solutions and primer systems used in the bonding of brackets on enamel colour change and bond strength. Materials and Methods: A total of 120 extracted premolar teeth were used. Teeth were divided into four main groups; brackets were bonded with 37% orthophosphoric acid + Transbond XT Primer in Group 1, 3M Single Bond Universal (3M Espe America) in Group 2 , Transbond Plus SEP in Group 3 (3M ESPE Dental Products; 3M Center, St Paul's, USA), and G-Premio Bond (GC, Tokyo, Japan) in Group 4. Each group was divided into three subgroups, and the teeth in Group A were placed in a cup containing coffee and tea mixture. The teeth in group B were placed in a cup containing cola, and the teeth in Group C were placed in distilled water. A bond strength test was applied to all teeth using a universal test device. Colour measurements of all teeth were performed using the Vita Easyshade spectrophotometer at 2 different times: before bonding and after the bond strength test. Results: The average bond strength of the 37% orthophosphoric acid group (33.5) was higher than that of the other groups. There was no significant difference in bond strength between the groups using Transbond Plus SEP (19,9), 3M Single Bond (20,57) and G-Premio Bond (20,75). No significant differences were observed in bond strength between the tea–coffee, cola and distilled water groups. A statistically significant difference was found between the distributions of adhesive remnant index (ARI ) scores according to the primers (p = 0.001). There was no significant difference between the distributions of the ARI scores according to the solutions (p = 0.335). The effect of primer and solution groups on colour change was statistically significant (p = 0.001 and p = 0.023 , respectively). Conclusion: In this study, the bond strength in the group using 37% orthophosphoric acid + Transbond XT primer was significantly higher than in all other groups. However, it was determined that the bond strength was clinically sufficient in all other primer groups. The highest colour change was observed when the tea–coffee solution and Transbond Plus SEP primer were used. There was no significant difference between the effects of the other primer groups on colour change. KEYWORDS: Bond strength, Tooth colour change, Primer, Solution