Is a primer needed for orthodontic bonding? : a randomised controlled trial

Is a primer needed for orthodontic bonding? A Randomised controlled trial Objective: To evaluate the clinical performance of APC Victory IITM (3M Unitek) brackets in direct orthodontic bonding with and without the use of primer. Design: A single operator two centre prospective randomised controlled clinical trial. Setting: The orthodontic departments at the Leeds Dental Institute and St.Luke’s hospital, Bradford. Subjects and methods: 92 patients requiring orthodontic treatment with fixed appliances. 46 Patients randomly allocated to control (with primer) or test (without primer). Patients bonded using a standardised procedure. Main outcome measures: Number of bracket failures, time to bond-up appliances and the adhesive remnant index (ARI) when bracket failure occurred, over a six month period Results: Failure rate with primer 8.8%, without primer 13.8%, no statistically significant difference- P value 0.051. Mean difference in bondup time per bracket was 0.068 minutes which was not statistically significant (P =0.402). Statistically significant difference in the ARI – ARI 0 with primer 55.9%, no primer 81.5%, (P= 8.1622e-008). Conclusion: There is no statistically significant difference in the bracket failure rate with or without primer when bonding APC Victory IITM (P=0.051). No significant difference in bond-up times. Statistically significant difference in the ARI, bonding without primer providing a lower ARI.