[Comparison of 1-stage orthodontic bonding systems and 2-stage bonding systems: a review of the literature and the results of a randomized clinical trial].

OBJECTIVE

The main objectives of this study are to present a literature review of self-etching primer's (SEP's) and present the outcomes of a prospective clinical trial to assess the clinical bond failure rates of orthodontic brackets bonded using a self-etching primer (SEP), compared with brackets bonded using a conventional acid-etched technique with a control adhesive (Transbond). A secondary aim was to investigate whether characteristics of the operator, patient or tooth bonded had any influence on bracket failure.

DESIGN

Single-centre randomized controlled clinical trial. Thirty-four patients were bonded, each being randomly assigned to either the test or control adhesive.

SETTING

Orthodontic Department Countess of Chester Hospital, Chester, UK.

SUBJECTS

Orthodontic patients requiring fixed appliance treatment.

MAIN OUTCOME MEASURES

Bond failure.

MAIN OUTCOME RESULTS

Failure rates over the initial 6-month period were 2.0% (Transbond) and 1.7% (SEP) with no statistically significant difference between the two groups. Over the duration of the fixed appliance treatment, bond failure rates increased, but remained acceptable at 7.4% (TB) and 7.0% (SEP), respectively. When operator, patient and tooth characteristics were analysed, only the bracket location was found to be significant. Maxillary brackets were more likely to fail than mandibular brackets (relative risk 0.47%; 95% confidence interval 0.22, 1.03). The failure rate for brackets in our study was low when compared with previous studies.

CONCLUSIONS

Both the acid-etched control and self-etching primer in combination with adhesive pre-coated brackets were successful for clinical bonding. Their combined failure rate was lower than that reported in similar trials. The literature on SEP's supports the findings of this study.