Effect of saliva moistening on shear bond strength of self ligating orthodontic brackets

The purpose of the present study was to compare Shear Bond Strength (SBS) and bond failure site of conventional and Self-Ligating (SL) orthodontic brackets, bonded on dry and saliva contaminated enamel. Approach: One conventional and three different types of self ligating stainless steel brackets were bonded onto 160 bovine permanent mandibular incisors, divided randomly into 8 groups, using Transbond XT adhesive system. For each type of bracket, 20 samples were bonded on dry enamel and 20 after saliva contamination. After 24 h all specimens were tested for SBS using an instron universal testing machine and Adhesive Remnant Index (ARI) were evaluated. Results: Saliva contamination significantly lowered SBS of conventional brackets. For self-ligating brackets no significant strength reduction was recorded. Conclusion: All the groups showed clinically adequate mean shear bond strengths. ARI scores in contaminated groups resulted lower than in dry groups.