The prevalence of dental caries overall has declined in many European countries but this has not occurred equally for all tooth surfaces. This makes site specific diagnosis of dental caries more important, especially on the occlusal surfaces which are commonly affected. Several methods of caries diagnosis have been used but most rely on the dentist's subjective interpretation of clinical findings.
The objective of investigation:
Currently, an objective and a well-defined process for classifying carious lesions clinically by QLF does not exist. The aims of this study were to: use QLF to quantify the extent of mineral loss in caries lesions using the histological gold standard and to develop an interpretative clinical index of QLF values.
Method:
100 unrestored extracted human posterior teeth were cleaned, clinical research methods ICDAS II scoring were used, images of five surfaces (occlusal, buccal, lingual, mesial and distal) for each tooth using different camera systems (White-light digital camera, QLF and Morita camera), periapical radiographs, histology, TMR (Transverse Micro-radiography) and Micro CT (Microcomputed tomography) were employed. All the information gathered and analysed with special software.
Results:
QLF scores were significantly different at ICDAS scores 1, 2, 3 and 4(p < 0.001). A QLF Index was developed to classify early carious lesions by the use of range of delta F at 5% and 95% Confidence Interval for Mean with the histology.
Conclusion:
Early indications suggest that QLF may enhance the identification of early demineralisation on the occlusal surface and plaque red fluorescence in carious lesions while images from Morita camera gives information regarding red fluorescence only. QLF was able to identify caries on the occlusal surface and differentiate between lesions of varying severity in early stages. It is anticipated that QLF will be valuable tool in routine clinical practice and reduce the patient's exposure to ionising radiation.