M Beerens

42 CHAPTER 3 3. microbiological samples were assessed to see if there is a difference between patients with and without WSL for total colony forming units (CFU’s) and percentages of aciduric flora, S. mutans, Lactobacillus spp. and C. albicans . MATERIALS AND METHODS This blinded cross-sectional study was performed as a part of a randomised clinical trial involving orthodontic patients with WSL on the buccal surface developed during fixed appliance treatment. The study was conducted in accordance with the ethical principles of the 64th WMA Declaration of Helsinki (October 2013, Brazil) and the Medical Research Involving Human Subjects Act (WMO), approximating Good Clinical Practice (CPMP/ICH/135/95) guidelines. The medical ethical committee of the University Medical Centre of the Free University of Amsterdam, the Netherlands approved this study (MEC7/213). Subjects Subjects undergoing full fixed appliance treatment therapy were recruited at the Department of Orthodontics, Academic Centre for Dentistry Amsterdam, The Netherlands. The subjects comprised a convenience sample meeting the following inclusion criteria: 1. Treated with orthodontic fixed appliances in both arches, 2. Healthy adolescent males and females between the ages of 12 and 19 years at debonding, and 3. Debonded between January 2008 and August 2009. Written informed consent was obtained from all participants, and in the case of minors, written informed consent was also obtained from the parents/ guardians. Subjects at the Department of Orthodontics were advised to brush twice a day with fluoride toothpaste and during fixed appliance treatment they were advised to clean around the brackets using an interdental brush. WSL were confirmed directly after debonding. The detection of lesions was performed through quantitative light-induced fluorescence (QLF) (Inspektor Research Systems B.V., Amsterdam, The Netherlands) combined with clinical examination.