Clinical Study: Digital Radiography vs. Near-Infrared Transillumination in Caries Detection

Objectives: To compare the effectiveness of detecting proximal carious lesions utilizing a new near-infrared transillumination (NIRTI) system (CariVu, Dexis) to traditional digital bitewing radiography (BWXR).
Methods: Thirty subjects were selected from patients presenting for their annual military dental examination and meeting eligibility criteria. A new set of four posterior BWXRs were taken with an intraoral radiographic unit (Planmeca Intra). At the subsequent study appointment, all premolars and molars were individually imaged with the NIRTI device and saved to the proprietary software (Dexis Imaging Suite 9.4.4). Sixty-seven proximal carious lesions were classified based on depth into enamel or dentin (0=sound surfaces, 1=first visible sign of enamel caries, 2=established carious lesion in enamel, 3=carious lesion reaching the DEJ, 4=carious lesion penetrating the DEJ, 5=established dentin caries) for both the BWXR and the NIRTI images. The digital images were reviewed in a standardized environment by three independent examiners. The interrater reliability between the three examiners was evaluated using intraclass correlation coefficient (ICC) for both BWXR and NIRTI (alpha = 0.05). The caries classification based on BWXR and NIRTI were compared using a Spearman correlation (alpha = 0.05).
Results: The ICC for the examiners was 0.98 (P<0.001) for BWXR and 0.87 for NIRTI (P<0.001). The caries depth classification between the two systems were strongly correlated (r_s=0.66; Spearman range: 0.60 – 0.79 = strong) and significant (P<0.001) with a median score of 3 for NIRTI and 2 for BWXR.
Conclusions: The new NIRTI system (CariVu) may serve as an adjunct to BWXR in the diagnosis of proximal caries. However, the caries were classified as greater in depth using the NIRTI compared to the traditional BWXR. In addition, there was greater variability in the caries depth classification between the three examiners with the NIRTI system compared to BWXR.