Determinants of the Canary System™ Efficacy in Early Caries Detection: An in Vitro Study

Aim: This study aimed to investigate how specific technical and oral factors influence the efficacy of the Canary System in detecting and quantifying early caries lesions Methodology: Forty extracted human teeth with early caries lesions were examined. Twenty teeth had lesions on the occlusal surfaces, while the remaining twenty had lesions on smooth surfaces. The lesions were assessed using the Canary System under various conditions to evaluate its accuracy. The following conditions were tested for the accuracy of the machine readings. (1) Presence of moisture, (2) the influence of the distance of the optical tip of the hand-piece to the lesion surface, (3) bacterial biofilm on the lesion, and (4) staining of the lesion, were investigated. Results: Tukey’s Multiple Comparison test revealed that moisture and staining significantly affected the Canary Numbers. Moisture presence resulted in significantly lower readings (28.63 ± 16.0, p < 0.01), while staining caused significantly higher readings (71.93 ± 21.9, p < 0.01) compared to dry-state examinations. In contrast, bacterial biofilm and the distance of the optical tip had no significant impact on the Canary Numbers. A similar trend was observed for lesions on occlusal surfaces. For lesions on smooth surfaces, only staining caused significantly higher readings (65.70 ± 16.89, p < 0.01) compared to the dry state Conclusions: The findings suggest that the efficacy of the Canary System in caries detection may be influenced by lesion staining on all surfaces and by the presence of moisture on occlusal surfaces.