In vitro study of the diagnostic performance of the Spectra Caries Detection Aid.

OBJECTIVE: The Spectra Caries Detection Aid is a fluorescent camera (FC) caries detector device that has been demonstrated to detect occlusal caries extending into dentin with good sensitivity and specificity. This in vitro study examined the diagnostic performance of this device with the goal of defining the numerical reading that best indicates that a tooth has dentin caries. METHODS: Ninety extracted human third molars, that either appeared clinically intact or had early occlusal caries, were used. Teeth were photographed then analyzed using the Spectra Caries detector. Following Spectra readings, the teeth were sectioned perpendicular to the long axis of the tooth. Cuts were made in such a way as to expose the dentino-enamel junction below the pits and fissures. The sectioned teeth were scored as being caries-free, having enamel caries, or dentin caries. Using each tooth's Spectra reading and histological diagnosis, the sensitivity and specificity for various potential dentin caries cut-off values were calculated. Also, the receiver operator curve (ROC) was plotted and the area under the curve calculated. RESULTS: At the manufacture's recommended cut-off for dentin caries diagnosis of 2, the sensitivity is 0.68 and the specificity is 0.78. At a lower cut-off value in the study reported here of 1.8, it was observed that the sensitivity is higher at 0.87, but that the specificity is lower at 0.7. The overall diagnostic performance of the Spectra is good with an ROC area under the curve of 0.82. CONCLUSION: Although lower cut-off values may have higher sensitivity, the use of the manufacture's established cut-off of 2 will result in fewer instances where dentin caries will be diagnosed incorrectly. The use of higher thresholds will discourage restorative treatment of early lesions that are best managed by sealants or other preventive approaches.

Effect of pit and fissure sealants on caries detection by a fluorescent camera system.

OBJECTIVE: The aim of this study was to evaluate the effect of sealant placement on the detection of caries by a fluorescent camera (FC), the Spectra caries detector. MATERIALS AND METHODS: In a laboratory study, FC images and readings were obtained from 31 extracted teeth, before and following application of clear sealants (Shofu Clear or Delton unfilled), or opaque sealants (3M Clinpro or Delton FS). Teeth were then sectioned and examined for enamel or dentine caries. Using each tooth's true caries diagnosis, the sensitivity and specificity of the FC measurements in detecting dentine caries was calculated. In the clinical study, FC readings were obtained from 41 molars in children prior to and following application of clear sealants. RESULTS: Following application of Shofu or Delton unfilled there were reductions in the mean FC readings of 10% (p=0.5) and 8.2% (p=0.009), respectively. Application of two opaque sealants, 3M or Delton FS significantly reduced mean FC readings 16.2% and 20.8% (p<0.5), respectively. Although the carious lesions could still be observed in FC images from teeth with opaque sealants there was a significant loss of sensitivity in detecting dentinal caries. Clear sealant application caused an insignificant loss of detection sensitivity. Following application of clear sealants to children's molars there was a small (4.01%) but significant (p<0.01) reduction in FC readings recorded from these teeth. CONCLUSIONS: The FC can detect caries under clear sealants with little loss of sensitivity. Although lesions can be seen through opaque sealants, loss of sensitivity precludes accurate lesion assessment.