Clinical utility of biofluorescence imaging for detecting secondary caries beneath esthetic restorations

Secondary caries represents a major cause of failure in esthetic restorations; however, early lesions beneath restorations are difficult to detect using conventional visual and radiographic examinations. This case report presents two clinical cases in which Quantitative light-induced fluorescence (QLF) imaging with Qraypen C (AIOBIO, Seoul, Republic of Korea) was used to overcome the limitations of traditional diagnostic methods and to effectively diagnose and manage secondary caries beneath esthetic restorations. In the first case involving tooth #27 of a 34-year-old female patient, distinct red fluorescence in the QLF image corroborated the presence of deep secondary caries suspected on radiographs and facilitated the treatment planning for root canal therapy. In the second case involving tooth #16 of a 31-year-old female patient, localized red fluorescence detected exclusively on the QLF image guided early preventive intervention, confirming a previously undetectable subclinical lesion and preserving pulp vitality. QLF technology enables the early visualization of secondary caries that are difficult to detect clinically or radiographically, thereby improving diagnostic accuracy. By providing information on lesion activity, QLF supports clinical decision-making across a range of treatment strategies, from early intervention to endodontic therapy, and serves as a valuable tool for enhancing communication with patients.