M Beerens

98 CHAPTER 5 the positive results found in vitro and in situ and contradicts the findings of in vivo study results. The question can also be raised if there was a similarity of intervention. As there might be a taste difference between the two products. Cross contamination is not to be expected as no siblings were included. In this study 27 participants per group was aimed for, as was assessed as the effect size. Unfortunately, due to drop out, it became lower resulting in 25 to 26 per group. The used power was 0.9. If using the power of 0.8, at least 20 participants should have been included. So, it is still acceptable to draw conclusions. The effect found is so small that, though statistically significant, it is still not clinically relevant. Implications The use of MI Paste Plus ® in patients with subsurface enamel lesions after orthodontic fixed appliance treatment does not show an additional superior improvement of these lesions on the long term as measured by means of QLF imaging, microbiological composition and its acidity, as well as by digital oral photographs. This suggests that there is no clinical evidence to support that MI Paste Plus ® is a remineralisation agent because it is not effective to improve post-orthodontic subsurface lesions. REGISTRATION This trial is registered in The Netherlands at Amsterdam Free University of the University Medical Centre medical ethical committee under number NL.199226.029.07. GC Benelux, Leuven, Belgium provided free supplies of MI Paste Plus ® used in the study. None of these authors or study received personnel or consulting payments or any other form of personal benefit from GC Benelux. TRIAL PROTOCOL Full details of the trial protocol NL.199226.029.07 are available on request.