OBJECTIVE: To evaluate, over a 6-month period, the clinical performance of a self-etch adhesive (Transbond Plus Self-Etching) compared with a conventional adhesive that uses the etch and rinse approach (Transbond XT). MATERIALS AND METHODS: One operator, using the straight-wire technique, placed 567 metallic brackets in 30 patients (age range 12-18 years) such that homologous teeth from the same arch received different materials. The brackets were bonded following the manufacturer's instruction except for the fact that the self-etch system was brushed for a longer time than recommended (10-15 seconds). The failure modes were visually classified into three modes: adhesive-enamel, adhesive-bracket, and cohesive failure. The survival rate of the brackets was estimated by Kaplan-Meier and log-rank test (P < .05). RESULTS: The failure rates of the conventional and self-etch [corrected] adhesives were 10.6% and 7.4%, respectively. The failure rate of the conventional system was 0.43 [corrected] times greater than that of the self-etch system. The self-etch adhesive showed a higher survival rate compared with the conventional system (P < .05). Most of the failures were cohesive and at the adhesive-enamel surface. No difference in the fracture debonding mode was observed for the materials. CONCLUSIONS: These findings indicate that the self-etch Transbond Plus Self-Etching can be safely used for orthodontic brackets because it provides higher survival rates than does the conventional Transbond XT.
OBJECTIVE: To evaluate, over a 6-month period, the clinical performance of a self-etch adhesive (Transbond Plus Self-Etching) compared with a conventional adhesive that uses the etch and rinse approach (Transbond XT). MATERIALS AND METHODS: One operator, using the straight-wire technique, placed 567 metallic brackets in 30 patients (age range 12-18 years) such that homologous teeth from the same arch received different materials. The brackets were bonded following the manufacturer's instruction except for the fact that the self-etch system was brushed for a longer time than recommended (10-15 seconds). The failure modes were visually classified into three modes: adhesive-enamel, adhesive-bracket, and cohesive failure. The survival rate of the brackets was estimated by Kaplan-Meier and log-rank test (P < .05). RESULTS: The failure rates of the conventional and self-etch [corrected] adhesives were 10.6% and 7.4%, respectively. The failure rate of the conventional system was 0.43 [corrected] times greater than that of the self-etch system. The self-etch adhesive showed a higher survival rate compared with the conventional system (P < .05). Most of the failures were cohesive and at the adhesive-enamel surface. No difference in the fracture debonding mode was observed for the materials. CONCLUSIONS: These findings indicate that the self-etch Transbond Plus Self-Etching can be safely used for orthodontic brackets because it provides higher survival rates than does the conventional Transbond XT.