Effects of sealant and self-etching primer on enamel decalcification. Part II: an in-vivo study.

INTRODUCTION A self-etching primer (SEP) saves valuable time by eliminating the many steps required to etch, rinse, and place a sealant before application of the adhesive and placement of the bracket. The purpose of this study was to compare the effects of a conventional etch and sealant (CES) and a SEP on enamel decalcification in vivo. METHODS Twenty-five patients who required comprehensive orthodontic treatment were included in this study. Before bonding, enamel surfaces were treated with either a CES (Light Bond, Reliance Orthodontic Products, Itasca, Ill) or a SEP (Transbond Plus, 3M Unitek, Monrovia, Calif) by using a split-arch technique. At the end of the observation period (18-24 months), the O'Leary plaque index was used to determine patients' oral-hygiene compliance, and enamel decalcification around the orthodontic bracket was scored based on the amount and severity of decalcification. Scanning electron microscopy images and x-ray spectrum analysis were performed to examine the etched pattern of the 2 bonding systems. Data were analyzed by using analysis of variance (ANOVA) and the Tukey-Kramer test; the confidence level was set at a significant level of P = 0.05. RESULTS Significantly higher decalcification scores were found in the SEP group (27.5%) compared with the CES group (13.9%, P <0.001). No significant differences were found in the decalcification scores for teeth in the maxillary and mandibular arches. Significant differences were found between level of hygiene and decalcification (P <0.0001). Patients with fair or poor hygiene compliance had higher decalcification scores in the SEP group than in the CES group. CONCLUSIONS Using a SEP might save chair time and improve cost-effectiveness, but it provides less resistance to enamel decalcification than a CES, especially in patients with poor oral hygiene.