M Beerens

EFFECTS OF MI PASTE PLUS ® : A 12-MONTHS FOLLOW-UP 5 81 The null hypothesis to be tested was that the in vivo use of commercially available MI Paste Plus ® , in addition to normal oral hygiene, does not have an effect on: 1) The remineralisation of WSL over time, 2) Plaque composition assessed as total counts of colony-forming units (CFUs) and percentage of aciduric bacteria, Streptococcus mutans , Lactobacillus spp., and Candida albicans , as well as plaque acidogenicity over time, and 3) The visual changes in WSL over time in patients during 1 year after the removal of fixed orthodontic appliances. MATERIALS AND METHODS The medical ethical committee of the University Medical Centre of the Free University Amsterdam, The Netherlands, approved this study protocol (NL.199226.029.07). Treatment of WSL in former orthodontic patients was assessed directly post-debonding until 12 months thereafter. This study determined the long-term effect of MI Paste Plus ® versus a control paste on caries lesion extent and microbial parameters. Trial design This trial was performed as a prospective, double-blinded, randomized, placebo-controlled superiority trial. The allocation of subjects followed a randomization scheme with stratification for gender. This resulted in an allocation ratio of 6:7 for MI Paste Plus ® and control paste. No changes to the original protocol were made during or after the trial. It was initially intended to also assess microbial diversity by Denaturing Gradient Gel Electrophoresis (DGGE). Due to improvements in molecular biology techniques used (Alcaraz et al. , 2012; Schulze-Schweifing et al. , 2014; Beerens et al. , 2017) as well as limitations experienced with DGGE (Beerens et al. , 2017), this method was not utilized.