Approximal caries detection with a LED based device in vivo

Objectives: The aim of the study was to evaluate a novel LED based device for approximal caries detection and compare the results to bitewing radiography.

Methods: Fifty-three teeth (premolars and molars) in fifty-three patients with visibly and/or radiographically apparent approximal lesions were included. Both clinical inspection and bitewing radiographs were evaluated to assess the extension of carious decay. Additionally, measurements with the probe of the LED device (D-Carie mini, Dentsply) were performed from the marginal ridge of the occlusal surface of each tooth. The reflected light was analyzed with respect to a caries-specific spectrum and the presence and extent of caries was characterized by an audible signal differentiating two frequencies (low, fast). The treatment decision was not based on the results of LED diagnostics. When operative intervention at a site was indicated, the extent of caries was determined after its removal.

Results: Both LED diagnosis and radiographic evaluation were dependent on the approximal carious decay (p<0.05, chi-square) with a higher measure of association between clinical carious extent and radiographic assessment (lambda=0.692) than between carious extent and LED diagnosis (lambda=0.538). ROC analysis of deep dentinal carious lesions (Az value: 0.864) showed highest sum of sensitivity and specificity for a high frequency and non-localized signal of the LED device.

Conclusion: Employing LED based caries diagnosis, it is possible to detect approximal lesions from the marginal ridge of the occlusal tooth surface. Furthermore, deep dentin caries can be distinguished from less extended carious lesions. Conventional methods for caries diagnosis could be amended by LED evaluation to reduce the number of radiographic examinations.