Plaque, or biofilm, is the term used to describe the microbial plaque that forms on the surfaces and in the approximal spaces (interdental spaces) of teeth when dental hygiene is inadequate. Demonstration of this bacterial plaque is a valuable aid for patients, enabling them to identify and target their oral hygiene deficits. A large number of microorganisms can be found in the oral cavity of every person, without this being a pathological (diseased) condition. Science now assumes that there are several thousand different types of germs. Together, these form a balanced, self-contained ecosystem that is difficult for other germs to penetrate. The germs that specialize in adhering to the hard surfaces of the teeth form what is known as plaque. Plaque development occurs in several phases:
- Immediately after the thorough cleaning of teeth, the so-called pellicle (pellicle, enamel epidermis) is formed.
- Within hours to two days, the initial repopulation by the microflora.
- After three days, in which the plaque could develop undisturbed, one speaks of young plaque. This is already organized so that the microorganisms are embedded in a polymer matrix produced by themselves.
- If you do not intervene for seven days, the mature plaque is formed.
If there is an oversupply of carbohydrates, preferably sugar (collective term for all sweet-tasting saccharides (single and double sugars) and trade name for the double sugar sucrose) in the mouth over a long period of time, this leads to increased growth of cariogenic (caries-causing) germs within the plaque. Mutans streptococci and lactobacilli are the most important of these. The sugar is quickly and effectively metabolized by Streptococcus mutans to lactic acid, which in turn leads to the preferential survival of germs within the plaque that can tolerate the acidic environment – again, the cariogenic mutans streptococci and lactobacilli are in the forefront. The acid, on the other hand, does the actual damage to the tooth structure: it is demineralized. The crystal structure, which gives the tooth hardness, is gradually dissolved by the acid, so that cavitation (loss of substance, creation of a “hole”) occurs in the further course. The shift in equilibrium within the plaque ecosystem caused by an excess of food for too long not only leads to an increased risk of caries for the tooth structure. This is because the increase in plaque over a longer period of time and the resulting impeded oxygen supply in the deeper layers cause germs to thrive there, which within a few days inevitably lead to gingivitis (inflammation of the gums) in the areas not reached by toothbrushing. If other unfavorable factors are added, inflammatory damage to the periodontium in the form of periodontitis can follow.
Indications (areas of application)
No plaque, no caries! Based on this simple formula, the indication for plaque demonstration arises whenever the specific motivation of a patient is required. Only by pointing out all bacterial nooks and crannies will he be able to regularly and consistently rid his teeth of plaque. The indication will vary in frequency depending on the individual findings. By means of so-called plaque or oral hygiene indices, the infestation of the teeth by plaque is recorded schematically and reproducibly. This enables an objective comparison to be made at follow-up examinations. Depending on the plaque findings, the dentist will make a recommendation for recall (to return to the practice) to supplement home dental care with professional dental cleaning (PZR) and fluoride application (application of fluoride varnish or similar) to reduce the risk of caries, if necessary.
Contraindications
There are no contraindications for bacterial plaque demonstration. The plaque revelers listed below (the staining of plaque bacteria is done with so-called plaque revelers) are classified and approved as safe for health. However, the use of erythrosine is contraindicated in cases of iodine allergy due to its iodine content. Gentianaviolet and fuchsin, on the other hand, are considered to be potentially carcinogenic (cancer-causing) as aniline dyes and are therefore no longer permitted for use as plaque revellers.
Before the examination
Before the examination must be present or take place:
- Patient consent to stain plaque must be obtained, as the entire oral mucosa may be affected by staining for several hours. In children and adolescents, consent is greater than in adults, whose motivation can be alternatively with the measurement of gingival pocket depths or bleeding indices.
- Advance explanations about the expected sight are useful, especially since the oral and lip mucosa may also be affected by staining.
- Previous application of petroleum jelly is advisable to prevent staining of the lips.
The procedures
I. Using liquid plaque-revelators, stain the biofilm as follows:
- Revelator is applied dabbing, not wiping, to tooth surfaces with a soaked cotton or foam pellet.
- The patient then removes excess stain by rinsing twice with water.
- In the mirror, the patient is explained all the findings relevant to him and is specifically made aware of the areas that he must include in his future brushing technique.
- The findings are recorded in a plaque index.
II. the use of chewable tablets is less recommended for dental practice, because, firstly, the chewing is often perceived as unpleasant, and secondly, the mucous membranes are more strongly stained with than with the direct application of the dye to the tooth surfaces described in I.. However, chewable tablets for home use are a useful way of checking the brushing training for the patient himself. Substances used as revelators include the following:
- Erythrosine (tetraiodofluorescin-Na, E 127, red coloring).
- Patent blue (brilliant blue, food coloring, E 133, blue coloring).
- Two-phase revelators (eg Mira-2 clay erythrosine-free): the young plaque of the initialization phase is colored pink, mature plaque appears blue. Through this effect can be targeted permanent cleaning deficiencies.
- Sodium fluorescein (PlaqueTest Vivadent) shimmers yellow, but only when illuminated with blue light (e.g. polymerization lamp).
After the examination
The use of plaquerevelators, with the exception of sodium fluorescein, requires professional dental cleaning, which removes the color deposits not only from the teeth, but also from the mucosa of the lips and tongue.
