Clinical Evaluation of Bond Failure Rates Using a New Self-Etching Primer

Objective: The purpose of this clinical study was to evaluate bond failure rate of brackets using Transbond Plus Self-Etching Primer (3M Unitek) that combines the etching, priming and bonding steps into one. Method: Twenty patients, ranging from ages 10 to 44, from the Ortho Department participated in the study. Bonding of brackets followed a contralateral quadrant pattern, which alternated randomly from patient to patient. Treatment of teeth in control quadrants included pumice prophylaxis, rinse and dry, etch with 37% phosphoric acid for 15 seconds, rinse and dry, applied Transbond XT Primer and light cured for 10 seconds, and bond bracket using Transbond XT resin cement and light cured for 20 seconds each from the mesial and distal. Treatment of the teeth in the experimental quadrants included pumice prophylaxis, rinse without drying completely, applied Transbond Plus Self-Etching Primer for 3 seconds to enamel surface without rinse. A burst of air was applied for 1-2 seconds, and bond brackets, using Transbond XT resin cement by light curing. Results: 348 teeth were bonded with 174 bonded using each method. Bond failures were recorded monthly over a 6-month period. Eight bond failures occurred in the control quadrant and only one bond failure occurred in the experimental quadrant. The Fischer’s Exact test was used to analyze the data. The bond failure rate using Transbond Plus Self-Etching Primer was significantly less than the bond failure rate in those quadrants where 37% phosphoric acid was used (p=0.037). Conclusion: Transbond Self-Etching Primer can be used to successfully bond orthodontic brackets, and in quadrants which were bonded with this material had significantly fewer bond failures than quadrants which were bonded using separate acid etch and primer.