M Beerens

34 CHAPTER 2 Reliability Inter-examiner reliability for ICDAS at T1 was 0.71 and at T2 was 0.73. Inter- examiner reliability for VT from T1 to T2 had an ICC of 0.72. The intra-examiner reliability (ICC) for ICDAS varied from 0.65 (T1) and 0.73 (T2) for examiner 1 to 0.66 (T1) and 0.72 (T2) for examiner 2. The intra-examiner reliabilities (ICC) for VT were 0.77 and 0.74 for examiners 1 and 2, respectively. For QLF, the intra-examiner (M.W.B) agreement was high, with an ICC of 0.93. The inter-examiner agreement with an experienced examiner (M.H.V) had an ICC of 0.87. DISCUSSION This study provides information on assessment of post-orthodontic buccal white spot lesions over time. The findings confirm regression of WSL after debonding of fixed orthodontic appliances and strengthen the evidence that not all lesions progress to cavities (Ferreira Zandona et al. , 2012). Monitoring post-orthodontic white spot lesions over time in a standardized way will provide information on the behaviour of these lesions and is therefore of clinical relevance. Assessment of WSL on routine digital oral photographs using ICDAS scores did not have sufficient discriminatory accuracy. The monitoring of these lesions by lesion assessment after orthodontics VT using routine digital oral photographs did provide a standardized manner to assess WSL progression or regression over time. Before considering the implications of the data of this study, it is important to consider the strengths and limitations of the study. Teeth were not dried prior to examination, so we were not able to score code 1 in clinical photographs and might therefore have underestimated the number of existing white spot lesions. ICDAS was developed for scoring in vivo and it has limitations for scoring on clinical photographs, especially for incipient lesions. In this study the continuum of caries has been described in ordinal scales for QLF as well as for ICDAS. This was done to be able to compare a continuous scale as used with QLF with an ordinal scale, as is the case with ICDAS. Alongside these limitations, this study also has a number of key strengths. Information on 918 surfaces of 51 patients was analysed. Two analysing methods were used: VT scoring and ICDAS scoring, to be able to detect and monitor over a 1-year timeframe. Photographs were used instead of in vivo assessment of the dentition with ICDAS, as commonly used. Using ICDAS does not allow side- by-side comparison and, thus, monitoring buccal white spot lesions over time