Evaluation of inter- and intra-examiner reproducibility of The Canary System

Objectives: The inter- and intra-examiner reproducibility of The Canary System (CS) for scanning smooth and occlusal surfaces with natural decay was evaluated in this in vitro study.
Methods: A total of 185 examination sites (92 on smooth surfaces and 93 on occlusal surfaces of extracted human teeth), with status ranging from visually sound to natural dentinal caries, were investigated using the same CS. Two blinded operators, each trained and experienced in caries detection using CS, independently performed three scan measurements for each site. Between each of the three measurements, the operator removed the tip of the handpiece from the site and counted a 10-second interval before re-positioning the tip onto the same site to take the next measurement. For each operator, the intra-examiner reproducibility of CS was estimated by calculation of the examiner’s intra-class correlation coefficient (ICC) using the three repeat measurements per site. The mean values of the three measurements per site was also recorded and were used to estimate inter-examiner reproducibility using ICC. Polarized Light Microscopy was used to histologically confirm the presence or absence of a caries lesion on each examined site.
Results: Table 1.
Conclusions: For both smooth and occlusal surfaces, CS demonstrated almost perfect intra-examiner reproducibility for both operators (ICC = 0.971-0.995). Inter-examiner reproducibility was higher for smooth surfaces (ICC = 0.929) than for occlusal surfaces (ICC = 0.853) most likely due to greater variability in the anatomic characteristics of the pits and fissures compared to smooth surfaces. Overall, this study demonstrated the ability of CS to detect caries on smooth and occlusal surfaces with excellent intra- and inter-examiner reproducibility.