Digital imaging fiber-optic trans-illumination, F-speed radiographic film and depth of approximal lesions.

BACKGROUND: Detection of early carious lesions is a prerequisite to an optimal preventive and minimal surgical intervention strategy. The authors conducted this study to determine whether Digital Imaging Fiber-Optic Trans-Illumination (DIFOTI) (Electro-Optical Sciences, Irvington, N.Y.) could be useful in evaluating early approximal lesions and to compare radiographs produced with F-speed film with both histologic lesion depth and cavitation.
METHODS: The authors created artificial approximal lesions in vitro in extracted teeth over 14 weeks and imaged them using a "bitewing-like" view every two weeks with DIFOTI and F-speed radiographic film. At the end of the 14 weeks, the authors examined the lesions for surface cavitation using visual and tactile methods. They then thin-sectioned the lesions and subjected them to histologic analysis using polarized light microscopy (PLM).
RESULTS: DIFOTI was not able to measure the depth of a lesion in any of the samples. It was, however, able to show surface changes associated with early demineralization as early as two weeks. The depth of a lesion measured using F-speed radiographic film was not statistically different from the depth of a lesion measured with PLM histologic analysis (P > .05). None of the lesions showed any signs of surface cavitation after 14 weeks of demineralization. CONCLUSIONS AND CLINICAL IMPLICATIONS: DIFOTI technology should not be used to decide between surgical or chemical treatment strategies based on lesion depth. We found that F-speed radiographic film was accurate in the approximating the depth of the lesion histologically. Ideally, the clinical decision whether to cut the tooth should be made based on cavitation rather than histologic lesion depth.