An in vitro Comparison between Laser Fluorescence and Visual Examination for Detection of Demineralization in Occlusal Pits and Fissures

Abstract

It has been demonstrated that when excited by laser light carious enamel appears dark compared to luminescent sound enamel. The aim of this study was to compare the sensitivity and specificity of visual exams (V), laser fluorescence (LF) and dye-enhanced LF (DELF) for detecting demineralization in occlusal pits and fissures. The actual presence of lesions was determined by subsequent confocal laser microscopy (CM), which was compared to histology (H). Independent clinical examiners visually graded three sites on occlusal surfaces of extracted, human premolars as sound or carious and also rated the color of each graded site as: 0 = same as surrounding enamel; 1 = white; 2 = light brown, or 3 = brown/dark brown. An argon laser was used to illuminate the teeth for LF and DELF; the images were captured with a CCD camera and then analyzed. DELF images were captured after the teeth had been exposed to 0.075% sodium fluorescein. Sections were then cut from each specimen and analyzed by CM and H for the presence or absence of caries. Results showed that DELF (0.72) was significantly more sensitive (p < 0.05) than LF (0.49) and V (0.03) for detecting caries, but there were no significant differences among the methods in specificity (V 1.00; LF 0.67; DELF 0.60). When color was used as an indication of caries in V (VC, sensitivity 0.47; specificity 0.70), V exams were not different from LF. The area under the ROC curve, using H as the gold standard and CM as the test, was 0.78. Results indicated that DELF was the best diagnostic tool and that VC and LF were equally effective as diagnostic methods, when color of fissures was included as an indication of demineralization in the visual exam.