Recently, there have been improvements in diagnostic methods for the assessment of early caries lesions. The reason is that dental professionals are seeking methods to reliably detect incipient dental caries and to remineralize them. This review examines the literature on principles, theoretical background, and history of the Quantitative Light-Induced Fluorescence (QLF) system (Inspektor Research Systems BV, The Netherlands). Furthermore, this paper discusses the potential application of QLF system to clinical practice for educational purpose, enabling dental hygiene students to perform oral health assessment using the QLF system. In addition, the clinical application of QLF system can motivate patients by providing additional visual information about caries and bacterial activity. The evidences on validity and reliability of the QLF system for detection of longitudinal changes in de/remineralization and caries were examined. The QLF system is capable of monitoring and quantifying mineral changes in early caries lesions. Therefore, it can be used to assess the impacts of caries preventive measures on the remineralization and reversal of the caries process. And the QLF system is a very promising equipment to assess educational effectiveness for dental hygiene students in their learning process. In conclusion, the QLF system is the most effective technology for more sensitive staging of caries and treatment without surgical intervention.