Laser-assisted caries diagnostics is a laser fluorescence spectroscopy method that takes advantage of the different fluorescence behavior of healthy and carious tooth structure to detect fissure caries in particular at an early stage. Fissures are the valleys that run through the relief of the tooth surface in the longitudinal and transverse directions. They may well be 1 mm deep and at the same time very narrow (50 μm). In addition, they can widen in depth in an hourglass shape. In unfavorable cases, fissures are therefore impossible to clean even with very good oral hygiene techniques, but they are easily accessible to cariogenic (caries-causing) germs. If the caries spreads to the bottom of the fissure, the enamel above it initially remains intact, and the caries eludes visual diagnosis (detection by the dentist’s eye) in the early stages. X-rays also do not always provide accurate results in the early stages of caries, due to the superimposition effects with the adjacent enamel structures.
Indications (areas of application)
Laser-based caries diagnostics is characterized by high diagnostic accuracy and reproducibility of results. It is a useful supplement to the clinical examination of supposedly caries-free teeth. Its great advantage lies in the early diagnosis of carious initial lesions (incipient caries), whereby preventive (precautionary) measures and/or minimally invasive restorations (filling therapy with the least possible loss of tooth structure) can be initiated. Laser-assisted caries diagnosis is used:
- In conjunction with the initial clinical examination,
- For follow-up controls of initial lesions,
- For success control of preventive therapy measures such as fluoridation and improvement of oral hygiene technique,
- To confirm clinical and/or radiographic findings and.
- As a planning aid for fissure sealing on the caries-free tooth.
Contraindications
Due to false positive measurement results, the procedure is not indicated for colored dental deposits such as.
- Tartar
- Black Stain (black tooth buildup in children up to puberty age, caused by chromogenetic bacteria without disease value).
- Tea, coffee and nicotine deposits.
- Color interference due to excessively dried tooth surfaces.
Before the examination
Since fluorescence is an optical measurement method and can therefore be influenced by colored deposits, the teeth that are to be examined must be well cleaned and slightly dried. Otherwise, the measurement result may be falsely positive, e.g., due to
The procedure
Laser light is monochromatic, coherent light of a defined wavelength. Upon irradiation with laser light, certain substances, including dental hard tissue, react with the physical phenomenon of fluorescence. Electrons that are raised to a higher energy level by the high-energy laser light release the released energy in the form of visible light when they fall back to their original energy level (spontaneous emission). Due to their content of bacteria and their metabolic products, carious changes fluoresce in a different wavelength than healthy tooth substance. The cleaned and dried fissures are scanned with the laser probe of the KaVo Diagnodent Pen with slight tilting movements in different directions. The fluorescence spectrum emitted by the tooth is recorded by a spectrometer and the spectral values associated with a caries are reproduced as peak values (maximum values). Thus, the measurement with the KaVo Diagnodent Pen correlates as follows:
| Peak value | Meaning of the peak value | Therapy |
| 0 < 5 | healthy fissure | normal prophylaxis (fluoride toothpaste) |
| 5 – 12 | incipient fused calcification | normal prophylaxis (fluoride toothpaste) |
| 13 – 25 | Enamel caries in the fissure | Intensive prophylaxis for remineralization, e.g.B. Fluoridation in the dental office, fluoride gel concentrates in home dental care. |
| > 25 | Dentine caries in the fissure | Minimally invasive filling therapy, e.g. composite filling and intensive prophylaxis |
The values are shown both on the display of the tabletop unit and on the wireless radio display of the handpiece. In addition, they are coupled with an acoustic signal, which facilitates the workflow by allowing the practitioner to keep his or her eyes on the teeth during the measurement. The KaVo Diagnodent device significantly improves caries detection, especially in the fissure area. The laser fluorescence method can also be used to diagnose proximal caries (caries starting from the interdental spaces), although it is more difficult there due to the limited space available for the measuring probe.
