Enamel microcrack inspection using near-infrared light transillumination with fluorescence staining

Enamel microcracks are often apparent in the teeth of elderly individuals. However, accurate clinical diagnosis of enamel microcracks is very difficult. The purpose of this study was to examine the utility of inspections for enamel microcracks using a near-infrared light transillumination device with fluorescence staining. Human upper incisors with typical enamel microcracks were selected. Grayscale pictures of each tooth specimen were then taken by digital camera under visible light as control. Every tooth specimen was stained using indocyanine green solutions, then examined, and photographed under visible light. All digital images were compared with the background enamel surface and measured using image analysis software. Inspection using near-infrared light transillumination with indocyanine green solution was effective for detecting the presence of enamel microcracks. This method offers a non-invasive method of chair-side diagnosis and appears effective for detecting the presence of enamel microcracks.