The earliest possible detection of a developing carious lesion is the task of differentiated caries diagnostics (English : caries diagnostics), to which several methods contribute. This is because it is usually not possible to detect caries at an early stage using only one method. The incidence of caries in the German population has decreased significantly in recent decades. In the 1970s and 1980s, the prevalence of caries in children was still about five times higher than today. In the meantime, caries lesions are no longer evenly distributed among all children, but a polarization has taken place such that only a small group of about 25% of children bears almost the entire caries problem. Despite the enormous decrease in caries, it is therefore important to diagnose caries not at the stage of cavitation (collapse of the tooth structure), but at the stage of its development, so that it can be treated accordingly in a minimally invasive manner (with as little loss of tooth structure as possible).
Indications (areas of application)
The indication for caries diagnosis arises during every routine dental examination of the dentition, i.e. at least once a year. It serves
- Caries progression control: enamel caries without surface indentations can be arrested (brought to a standstill) by prophylactic measures. In this case, a close-meshed control is essential.
- Of early and reliable detection (recognition). The methods used in this regard should be as less invasive as possible and provide opportunities to assess the caries activity, as it depends on what therapy must be initiated.
The differentiated and early diagnosis is, in addition to dental prophylaxis, the most important measure to help a patient achieve lasting dental health with minimal loss of tooth structure.
Contraindications
Contraindications arise with radiographic examinations due to a patient’s lack of cooperation during the admission process. If this is anticipated in advance, radiography must be omitted for radiation protection reasons.
The procedures
A combination of several methods is useful for caries diagnosis during the course of a clinical examination:
Visual diagnosis
The tooth, ideally cleaned and dried, is examined for discoloration and cavitations (intrusions of hard substance) by viewing it with the aid of a dental mirror under good illumination. The purely visual assessment of the approximal spaces (interdental spaces) is only inadequately possible. So-called diagnostic systems (DMF index, ICDAS, UniViSS, etc.) are used for visual methods in order to detect the different degrees of caries severity. Tactile probing
In this case, the dental probe is used as an aid in the clinical examination. However, this examination method provides only slightly more results than the visual method, but can lead to the collapse of less mineralized enamel if the procedure is not carried out properly, so it can be dispensed with. Fiber optic transillumination
Fiber optic transillumination (FOTI, diaphanoscopy, fiber optic transillumination) is a practical and very important diagnostic procedure in which the tooth structure is transilluminated with a powerful light source, a so-called cold light probe. The different light refraction behavior of healthy and carious tooth structure is exploited. Carious substance becomes visible as a dark shadow due to a loss of light intensity. The procedure is characterized by a very high detection rate of dental caries. X-ray examination
X-ray examination using conventional or digital technology: so-called bite wing images (BF) make a decisive contribution to the diagnosis of enamel lesions. For approximal lesions (in the interdental space), 90% of which are detected with the bite wing technique, this is therefore the method of choice. Dental caries always lags behind its actual extent in the X-ray image, since only zones that have already been demineralized by bacterial activity and are therefore more radiolucent can be diagnosed as carious. In this case, FOTI and X-ray examination complement each other in the diagnosis. Before taking an X-ray, a justifiable indication must first be carefully established.In the case of children who are not willing to cooperate, X-ray diagnostics must be dispensed with in the interests of radiation protection. Diagnostics using the bite wing technique is particularly recommended at the age of approx. 15 years, when all permanent teeth have already erupted a few years. At this time, hidden occlusal and proximal lesions (on the occlusal surfaces and in the interdental spaces) can still be detected in time. Laser-assisted caries diagnostics
Laser-assisted caries diagnostics (laser fluorescence measurement) is performed as follows: Light from a laser fluorescence device (e.g. Diagnodent pen) with a wavelength of 650 nm is absorbed by both organic and inorganic matter. A carious lesion is excited to fluorescence. The fluorescence is coupled with an acoustic signal. Laser fluorescence measurement is a useful addition to the assessment of occlusal surfaces (chewing surfaces). Electrical resistance measurement
Electrical resistance measurement (impedance measurement) is based on the principle that saliva moist tooth hard substances have different electrical resistances. As the pore volume increases, including in carious tooth substance, the saliva content increases. This improves the conductivity, which leads to a decrease in resistance. Caries detector
If the aim is to make caries visible in the course of dental treatment for excavation (removal), chemical staining of the carious lesion with a so-called caries detector can be helpful; however, the procedure should no longer be used with increasing proximity to the pulp (tooth pulp), since in the vicinity of the pulp the healthy dentin (tooth bone) is stained more strongly due to its morphology and there is thus a risk of pulp opening. Here, the experienced dentist relies on the typical probing sound of the dentin when scanning with the probe.
