Determinants of enamel decalcification during simulated orthodontic treatment

Abstract

Objective: To determine the relative effects that phosphoric acid etching, metal brackets, composite resin adhesives, and filled resin sealants have on enamel decalcification. Materials and Methods: One hundred and fifty teeth were randomly divided into six groups to test the effects of acid etching, brackets, and a composite resin adhesive. The right side of each tooth was sealed. The teeth were submitted to a simulated carious challenge by Streptococcus mutans in a nutritive media for 42 days. Scanning electron photomicrographs (SEMs) were used to qualitatively evaluate the tooth surfaces. DIAGNOdent laser fluorescence was used to quantify the decalcification changes that occurred. Results: SEMs showed normal enamel on the control teeth, etching patterns on the acid-etched teeth, surface degradation on the teeth that had resin, and sealant tags on the sealed side. The untreated control group showed significantly less decalcification (P ≤.05) than did all groups except the no etch+bracket group. The no etch+bracket group showed significantly less decalcification than did the etch+bracket, no etch+resin, and the etch+resin groups. Acid-etched teeth demonstrated significantly more decalcification (34%) than did those that were not etched. The teeth with resin showed significantly more decalcification (24%) than did those without resin. There was no significant difference between teeth that did and did not have brackets. The unsealed side of the teeth showed small amounts of-but significantly more-decalcification (5%) compared to the sealed side. Conclusions: Acid etching and composite resin adhesives increase enamel decalcification in vitro, while brackets do not. Filled resin sealants protect the teeth from decalcification. © 2011 by The EH Angle Education and Research Foundation, Inc.