Effects of one-step orthodontic adhesive on microleakage and bracket bond strength: An in vitro comparative study

To evaluate the effects of one-step orthodontic composite combined with primer on microleakage and shear bond strength (SBS) of metal and ceramic brackets.

This in vitro study included 144 extracted premolar teeth. Teeth were divided into two main groups according to the bracket type (metal and ceramic). In each group, brackets were bonded with three different bonding systems: two-step total-etch (37% phosphoric acid+Transbond XT primer+Transbond XT light cure adhesive), one-step self-etch (Transbond Plus self-etch primer+Transbond XT light cure adhesive), and one-step orthodontic adhesive (37% phosphoric acid+GC Ortho Connect light cure adhesive). A total of 6 groups (n=12) were performed for each evaluation. All samples were subjected to thermal cycling. After dye penetration, sections were prepared and assessed under stereomicroscope. After SBS test, adhesive remnant index (ARI) scores were determined. Data were analyzed statistically.

There were no significant differences between total-etch and one-step orthodontic adhesive for microleakage. Self-etch adhesive showed more microleakage at occlusal interfaces (P<0.05). The highest and lowest mean SBS values were found in ceramic brackets bonded with total- and self-etch adhesives, respectively. No significant differences were found among the SBS values of the groups. However, the differences between ARI scores were found statistically significant (P<0.05).

Orthodontic composite integrated with primer can be used safely instead of two-step total-etch adhesives during the bonding of metal and ceramic brackets due to less microleakage and adequate SBS values.