Enamel loss following ceramic bracket debonding: A quantitative analysis in vitro.

Abstract

To measure enamel surface changes after ceramic bracket debonding and after cleanup. Forty extracted teeth were scanned in three dimensions using an optical scanner (baseline). Two ceramic bracket systems were placed (19 metal-reinforced polycrystalline ceramic brackets; 21 monocrystalline ceramic brackets). Seven days later, brackets were debonded and teeth scanned (post-debond). Adhesive remnants and bracket fragments were recorded. Tooth surfaces were cleaned using a finishing carbide bur and scanned again (post-cleanup). Post-debond and post-cleanup scans were aligned with the baseline, and surface changes were quantified. Results were statistically compared using t-tests and Mann-Whitney tests (α = .05). The depth of enamel loss (mean ± standard deviation) post-debond was 21 ± 8 µm and 33 µm and post-cleanup was 28 ± 14 µm and 18 ± 8 µm (P = .0191); the post-debond remnant thickness was 188 ± 113 µm and 120 ± 37 µm (P = .2381) and post-cleanup was 16 ± 5 µm and 15 µm for polycrystalline and monocrystalline ceramic brackets, respectively. The monocrystalline ceramic brackets predominantly left all adhesive on the tooth; the polycrystalline ceramic brackets were more likely to leave bracket fragments attached. Both systems allowed successful removal of the brackets with minimal enamel loss. However, the polycrystalline ceramic brackets left more fragments on the tooth, which complicated cleanup efforts.