M Beerens

70 CHAPTER 4 the literature (Boersma et al. , 2005; Sanpei et al. , 2010) it was noted, first, that these studies isolated S. mutans and Lactobacillus spp. from saliva, and, second, that a dip-slide test or a test strip was used. The use of such tests may not be valid in cases where S. mutans outnumbers Lactobacillus spp. to such an extent that the Rogosa agar on the CPP-ACFP strip displays S. mutans rather than Lactobacillus spp. In such tests the colony morphology typically is not checked. The finding, that the numbers of both aciduric bacteria and S. mutans decrease slowly after debonding (Table 3), indicates that the composition of plaque becomes less cariogenic after debonding. A longer follow-up period, however, seems necessary to evaluate if a healthy plaque ecology is re-established. Using QLF as an assessment method is, as described by Bröchner, a reflectional method to clinical scores (Boersma et al. , 2005; Ferreira Zandona et al. , 2010). With the use of QLF important additional data can be obtained concerning depth and precise area measurement. QLF has been accepted as a detection method in longitudinal observation (Stookey, 2004; Ferreira Zandona et al. , 2010). The QLF technique has been applied in several controlled clinical trials, with the consistent observation that it is capable of monitoring and quantifying changes in the mineral content and size of clinically visible non-cavitated WSL and can therefore be used to assess the impact of reversal of the caries process (Stookey, 2004; Ferreira Zandona et al. , 2010). The benefits of the QLF technique were apparent, especially in a longitudinal in vivo observation of demineralisation and remineralisation processes (Ferreira Zandona et al. , 2010). The additional use of International Caries Detection and Assessment System (ICDAS) could help to make data more comparable among studies, but with lesions only classified by ICDAS scores 2 and 3, the scale was considered too crude in comparison with the continuous scale of QLF. As in any clinical trial, compliance is an important issue. In this study the subjects were adolescents, a population where sometimes compliance is difficult to achieve. The use of the paste supplementary to tooth brushing twice a day was considered to be difficult to maintain by many subjects, and brushing and application of paste were forgotten, on average, once per week during the last 6 weeks of the study. The taste of the CPP-ACPF is quite different from that of ordinary fluoridated toothpastes commercially available in the Netherlands. While noncompliance because of disliking the taste of the CPP-ACPF paste was expected, only two subjects complained about the taste, but continued the study nevertheless. The high number of seven dropouts in