Influence of orthodontic treatment with fixed appliances on enamel color: a systematic review

Background: The purposes of this systematic review were to identify and review the orthodontic literature with regard to enamel color alterations after orthodontic treatment with fixed appliances. The effects of clean-up procedures on the surface of enamel were also investigated. Methods: We searched the following electronic databases: Medline (1950 to 6 July 2014), EMBASE via OVID (1980 to 6 July 2014), Google Scholar, Web of Science (1950 to 6 July 2014), CENTRAL (The Cochrane Library, 2014, Issue 7). We also searched the reference lists of relevant articles. Quality assessment of the included articles was performed. Two authors were responsible for study selection, validity assessment, and data extraction. Results: Five studies met the inclusion criteria, including 3 randomized controlled trials and 2 prospective studies. Four trials were assessed as being unclear with regard to risk of bias. One was assessed as being at high risk of bias. The studies reviewed suggested that orthodontic treatment alters the original color of enamel, and both adhesive systems and resin-removal methods can contribute to this change. Conclusion: There is no strong evidence from this review that orthodontic treatment with fixed appliances alters the original color of enamel. Further well-designed and conducted randomized controlled trials are required, to facilitate comparisons of results.