A comparative in vivo assessment of the long-term failure rate of 2 self-etching primers.

INTRODUCTION: The purpose of this study was to comparatively assess the failure rate of brackets bonded with 2 self-etching adhesives after 14 months of treatment.
METHODS: Twenty-two patients with complete permanent dentitions, and similar treatment plans and mechanotherapies, were selected for the study. Four hundred twenty-three brackets were bonded by using a split-mouth design, with Transbond Plus Self-Etching Primer (3M Unitek, Monrovia, Calif) or One-Step Self-Etching Primer (Reliance, Itasca, Ill). These self-etching primers were applied alternately so that they were equally distributed on the maxillary and mandibular right and left quadrants.
RESULTS: Failure rates were recorded for 14 months and analyzed with the chi-square test at alpha = 0.05 level of significance. Overall total failure rates were 0.94%, for Transbond Plus and 8.10% for One-Step. Although significantly more failures were found for the mandibular arch, no difference was identified in failure rate between anterior and posterior teeth. The results of this study suggest that care should be taken in ensuring the compatibility of retainers with adhesives.