Caries diagnosis before its occurrence.
Regular brushing is not one-hundred percent protection from caries.
Many factors can affect the development of the disease: heredity, maladaptation, chronic diseases, etc. Early diagnosis of the condition of teeth can save them from destruction. One such method is the CRT test.
CRT - color reaction in time, which in translation means a color index in time - a test by which you can estimate the degree of acid resistance of enamel of teeth.
What is taken as the basis of the test
Saliva is a natural protection for the oral cavity and teeth. The acid-base balance in the mouth depends on its quality and quantity. But under the influence of pathological factors, pH of saliva is constantly changing, often with a neutral passage into acid.
As you know, the acidic medium contributes to the destruction of the enamel (protective covering of the tooth) and causes a carious process. On this principle and based on the method of CRT: affecting the enamel of teeth with acid, you can find out the degree of resistance and stability.
How CRT-test is conducted
The left or right cutter is usually searched. The front surface of the tooth using cotton swabs is thoroughly cleaned from the plaque with a mixture of powder of pumice and chalk, dried with warm air and removed saliva. Then on its surface is placed indicator paper with a diameter of about 2 mm, impregnated with an automatic micropipette of 1.5 μm hydrochloric acid (1 mol/l). After that the time passes.
What shows the test
Indicator paper should change the color from light green to pinkish-purple. How long it takes for that to happen is impossible to say. Every person is different from 30 seconds to 2 minutes. The time elapsed since the application of acid to change the color of the indicator, and is the same color index of the stability of enamel to acids.
The longer the color reaction (in CRT), the higher the stability of the enamel and the less likely the formation of caries.
- Sample error is relatively high (up to 8%).
- The application of strong acids, albeit in a dosage amount, on healthy teeth is still harmful to the enamel. This can reduce its resistance and affect the development of caries.
- Detects the degree of risk of caries.
- Allows you to make an individual program for the prevention of oral cavity diseases (proper nutrition, care, observation). The test helps in the selection of hygiene products (toothpaste, rinse aid), able to maintain the required microflora in the oral cavity and thereby prevent the formation of caries.