Is a Primer Needed for Orthodontic Bonding? A Multi-centre Trial

Orthodontic treatment is carried out by placing fixed attachments(brackets)on teeth with wires which run through them and create tooth movement. These metal brackets are bonded (glued) onto the tooth surface by a three step process. Firstly, a mild acid is used to roughen the tooth surface, secondly a free flowing glue (composite primer) is used to fill in the roughened pores and thirdly, the bracket is glued on to the tooth surface with a \'composite\' material which sets hard by exposure to a high intensity light.The success of this procedure is measured by bracket failure rates. The literature review suggests that the scientific evidence is not clear to indicate whether the use of a primer is absolutely essential to achieve acceptable bracket success rates in a clinical environment. The primary aim of the study is to find out if the rate of loss of orthodontic brackets is clinically acceptable when they are glued onto the tooth surface without the use of a primer as compared to brackets bonded with a primer over a 12 month study period. The investigators will also investigate the Bonding time,Type of bracket bond failure,length of treatment and Peer Assessment Rating scores (PAR) This RCT will be undertaken on consented NHS patients in 3 hospitals in Yorkshire region by multiple operators The results from this study will help improve our knowledge of the best approach to bonding metal brackets on teeth. If the bracket failure rate is similar in both groups, this would indicate that the use of a primer is not always necessary. For patients, this would mean lesser time required to place brackets at the start of orthodontic treatment. For clinicians and NHS purchasers the outcome will influence cost effectiveness (as the primer is the most expensive component in the bonding process) and provide a framework for future studies.