Carious lesions occurring in the hard tissues of the tooth are the result of various factors and pathological processes, the level of development of which is the basis for caries diagnosis.
A good diagnostic method is one that is objective, quantitative, detects caries at the earliest possible stage and is accurate, precise and has a high sensitivity and specificity.
There is a classification of diagnostic methods into subjective methods, which include, among others, visual inspection, X-ray radiography and digital radiography, and objective methods, such as electrical conductivity testing (ECM), computed tomography, fluorescence under laser light and QLF (Quantitative Light Induced Fluorescence). QLF is a quantitative light-induced fluorescence method for detecting carious lesions. This new method is highly sensitive in determining short-term changes in oral cavities.
White teeth, photo: pantherstock
The method involves illuminating the teeth with an intense blue light, causing the teeth to emit light in the green part of the spectrum. This is closely related to the mineral content of the tooth enamel - if the teeth emit green light poorly, this indicates demineralisation. The QLF, through a tube leading into the mouth, emits a strong blue light. This tube is equipped with a camera with the appropriate filters so that the fluorescent image from the mouth can be seen on the computer screen.
A recent modification of the QLF, allows the precise determination of plaque, calculus, discolouration and oral hygiene status. It is a very good tool for caries prevention, as carious lesions can be detected very early. Another important feature of the QLF is that it can detect bacteria in the mouth thanks to the red fluorescence emitted by the bacteria. If red fluorescence is present in the examination, this indicates bacterial activity in the mouth. [1]
