RESUMO
INTRODUCTION: Our aim in this randomized clinical trial was to compare the failure rates of orthodontic brackets by using 2 self-etching primers (SEPs) (Transbond Plus [3M Unitek, Seefeld, Germany] and Clearfil Protect Bond [Kuraray Medical, Okayama, Japan]) with a split-mouth design. Additionally, the effect of Clearfil Protect Bond was investigated regarding inhibition of plaque accumulation and demineralization. METHODS: A total of 480 brackets were bonded in 24 patients with the SEPs. The observation period was 12 months. One week after bonding and at every third recall, the plaque index and a visual rating of the enamel adjacent to the bracket were assessed at the lateral incisors and the first premolars. Additionally, DIAGNOdent (KaVo, Biberach, Germany) values were measured. RESULTS: Over the investigation time, 26 failures were recorded. Five occurred with the brackets bonded with Transbond Plus, and the rest with Clearfil Protect Bond (P = 0.002). The additionally observed parameters had no significant differences. CONCLUSIONS: The failure rate with Clearfil Protect Bond was significantly higher. For our patients, who had adequate oral hygiene, there was no benefit with regard to plaque accumulation and prevention of demineralization with Clearfil Protect Bond.