A Randomized Controlled Trial to Investigate Brackets Bonded with a Hydrophilic Primer

Objective: To compare the clinical failure rates of brackets bonded using a prototype hydrophilic primer, designed to be insensitive to moisture, with brackets bonded with a conventional primer.Design: Single centre randomised controlled clinical study. Thirty-three patients were bonded using a split mouth technique: randomly allocating the hydrophilic primer to one side of the mouth and a conventional primer to the other.Setting: Hospital orthodontic department, Bradford, UK.Subjects: Orthodontic patients requiring fixed appliancesMain outcome measures: The site and time to bond failure was recorded for each bracket that failed over 6 months.Results: Using survival analysis, there was an increased risk of bracket failure when bonded with the hydrophilic primer compared with the conventional primer (hazard ratio = 2•2, 95% confidence interval: 1•1 to 4•5, P = 0•01).Conclusions: This hydrophilic primer cannot be recommended for routine clinical use.