Assessing Endodontic Treatment Feasibility for Cracked Teeth Using Quantitative Light-Induced Fluorescence: A Retrospective Clinical Study

Introduction: Cracked teeth present diagnostic and treatment challenges due to their complex etiology and uncertain prognoses. This study evaluated the potential of quantitative light-induced fluorescence (QLF) technology for diagnosing cracked teeth and its utility in predicting the need for root canal treatment (RCT). Methods: A total of 207 cracked teeth from 149 patients diagnosed between April 2019 and April 2023 were analyzed. QLF parameters (DF, DFmax, DR, DRmax) were measured using a Qraypen C device and analyzed with specialized software. Clinical characteristics, including age, sex, symptoms, tooth number, restoration type, pulp vitality, and crack direction, were recorded. The patients were monitored until August 2023, with an average follow-up of 19.1 months. Statistical analyses included t tests, analysis of variance, correlation analysis, and logistic regression analyses. Results: Of the 207 cracked teeth, 44 (21.3%) underwent RCT and 4 (1.9%) were extracted during the follow-up period. The QLF parameters differed significantly between teeth receiving restorative treatment and those requiring RCT (P < .0001). Cracked teeth with DF <-10, DFmax <-30, DR >15, or DRmax >30 had approximately 60% probability of undergoing RCT (P < .05). Logistic regression analysis confirmed that all QLF parameters correlated with RCT probability (P < .0001). Conclusions: This study demonstrated the utility of QLF technology in diagnosing cracked teeth and aiding treatment decision-making. The results suggest that careful monitoring, based on clinical evidence, is necessary before definitive restoration, particularly for cracked teeth with QLF parameters that exceed certain thresholds. Further studies with standardized protocols are required to validate the clinical application of QLF. (J Endod 2025;51:577-584.)