The inclusion of white spot lesions in caries diagnosis is important because they are highly prevalent in the first years of life, indicate caries activity, its detection might contribute to early intervention and the precision in clinical trials of
preventive agents is improved (34). Although some difficulty in distinguishing white spots from hypoplastic defects, the error in the diagnosis of caries is likely to be small and equally distributed among the intervention and control groups, because the intra-examiner reproducibility was optimal and the examiner was blinded to the child’s group status.
Some information bias may exist with regard to reported dietary practices: mothers from intervention group may have reported healthier practices to please the research staff. However, it is impossible to fully blind patients in studies in which the intervention involves dietary guidance (35). To minimize this problem, the research assessments were carried out by fieldworkers who had not applied the intervention.