Clinical applications of a quantitative light-induced fluorescent (QLF) device in the detection and management of cracked teeth: A case report

The aim of this case report was to discuss the clinical application using a quantitative light-induced fluorescent (QLF) device for the diagnosis and treatment of a cracked tooth as visualizing the tooth's crack. A 39-year-old woman visited a dental hospital complaining of throbbing pain on tooth #36. Observation of the tooth with naked eyes showed that tooth had a ceramic restoration with no specific findings. QLF device's images around the restoration, and after removal of the restoration were taken. In the QLF image after removal of the restoration, clear red-fluorescent crack line was shown, indicating that microorganism had penetrated along the crack path. During root canal treatment, the QLF image of the inside of the pulp chamber showed a pattern in which the crack line progressed into the tooth. During the treatment of the cracked tooth, the crack line was removed as much as possible using the fluorescent information obtained by the QLF device, and crack lines of fluorescence images quantitatively analyzed using a QLF's software. Images acquired with the QLF device can provide useful information for detecting crack lines, recording the treatment process, and restorative management of cracked teeth.