In dentistry, antimicrobial conditioning is the application of a protective antibacterial varnish to selected tooth surfaces at increased risk of caries with the goal of reducing bacterial activity over an extended period of time.
Composition and mode of action of the protective varnish
For example, chlorhexidine (CHX) and thymol are used as antibacterially active substances in the Cervitec Plus protective varnish in 1% concentrations each, although the concentration is ten times higher when used regularly after drying on the tooth surface. The two components exert a synergistic effect on each other, i.e. they each act more effectively in combination than chlorhexidine and thymol alone. The combination of active ingredients has a reducing effect on the activity of
- Gram-positive germs (Streptococcus mutans, Streptococcus sobrinus, Lactobacilli).
- Gram-negative germs (Actinomyces)
- Yeast fungi (Candida albicans)
Germ reduction effectively reduces the risk of tooth decay and prevention (precaution) against gingivitis (inflammation of the gums). The higher the concentration of active ingredients, the more effective the achieved germ reduction. In experiments with 40% chlorhexidine varnish, it has been demonstrated that
- After application to fissures (pits in the occlusal relief of the posterior teeth), bacterial activity was still significantly reduced after 22 weeks
- After application to exposed root surfaces, the loss of mineralized hard tissue was reduced by approximately 80%. Antimicrobial varnishes have therefore been established as an ideal material for the prevention of rapidly progressive root caries.
In addition to the effectiveness of the active ingredients used, the decisive factor is the varnish retention time (residence time of the varnish) on the treated tooth surfaces. In the example of Cervitec Plus, it is a polyvinyl butyral varnish base, with which, assuming optimal application technique, an excellent varnish retention time can be achieved. However, even with optimum varnish retention, it will come off after a few days at the latest. The long-lasting protection is therefore not due to an equally long adhesion of the varnish; rather, a long-term antimicrobial effect unfolds long after it has peeled off due to the following mechanisms of action:
- The varnish has an affinity for organic structures such as those present in the pellicle (wafer-thin tooth-surface membrane that is immediately re-formed from saliva after brushing). In it, an active ingredient storage with long-term effect.
- The active ingredients have a direct bactericidal (germicidal) effect on the plaque bacteria, which adhere to the pellicle (dental epidermis or also called “pellicula dentis”; this is a thin film of proteins of saliva), v. a. on the primary caries causer Streptococcus mutans.
- Chlorhexidine diffuses through the pellicles into the underlying tooth hard substances enamel, dentin (dentin) and root and forms a depot there.
- Chlorhexidine diffuses into the saliva and is released there from the hard substance depots longer term.
Indications (areas of application)
Although such high concentrations of active ingredients are not used in practice, even at lower concentrations, there is a significant reduction in bacterial activity. Thus, according to the manufacturer’s information, Cervitec Plus serves the following purposes
- To reduce a high risk of caries (e.g., in the case of already existing smooth-surface caries) in the case of insufficient oral hygiene.
- In xerostomia (dry mouth), which is always associated with an increased risk of caries.
- In case of lack of compliance (ability to cooperate) of the patient, e.g. due to motor or mental limitations.
- With implants
- For intensive protection in the case of exposed root surfaces and open dentinal tubules (tubules in the dentin, which are connected to the pulp).
- For the protection of fissures
- For application on approximal surfaces (tooth surfaces in the interdental spaces).
- During orthodontic treatment with fixed appliances.
- To protect against crown marginal caries.
Before treatment
Before treatment, professional cleaning of the risk surfaces to be treated is recommended, although cleaning is not mandatory, as the paint can also penetrate a – thin – layer of plaque.
The procedure
After cleaning, the teeth are drained, for example, quadrant by quadrant (one side of the upper jaw and one side of the lower jaw). Relative drying with cotton rolls, small saliva ejector and drying with the air nozzle is sufficient. The varnish is then applied to the risk areas with pinpoint accuracy using a microbrush (a small brush). Afterwards, a drying time of 30 seconds must be observed without the aid of the air nozzle. The patient must not rinse immediately after application.
After treatment
According to the manufacturer’s instructions, the patient must not eat or drink for one hour after treatment. Earlier recommendations were quite more restrictive and even excluded brushing teeth for one day and flossing for three days. Since the longest possible varnish retention period is desirable, these older care instructions may well still be considered reasonable.
