Sir,The recent publication on “Caries-risk assessment with a chairside optical spectroscopic sensor (OSS)” is very interesting.[1] Shrestha et al. have concluded that “The significant correlation of the acidogenic-profile determined using the OSS and the caries-status highlighted the OSS as a sensitive and rapid chairside tool for the quantification of the acidogenic-profile of saliva that could help in monitoring the caries-risk in children.[1] ” However, I would like to offer the following considerations: First, to judge any test as a tool for monitoring of pathological condition, it requires complete evaluation of diagnostic properties (sensitivity, specific, accuracy and etc.) This specific information is missing in this report. In addition, only very few samples were tested that could weaken the conclusion of this work. Second, though OSS is a good tool, its cost might not be affordable for settings with limited resources.