Studies radically changed our understanding of periodontal diseases and their effect on the body. For many decades, information about periodontal disease has remained virtually unchanged, but scientific advances in the last 10 years have shown an association of the oral cavity with a state of general health, where periodontitis is the key to a number of systemic diseases, either causing them or complicating their course.
Many conditions of the body are associated with the biofilm of the oral cavity: cardiovascular diseases, diabetes, lung diseases, kidneys and osteoporosis. Also, the relationship between prostate diseases, colorectal cancer and pancreas, the problematic resolution of pregnancy (including premature births and low birth weight), with oral biofilm, which causes periodontal disease, has been proven. But what is biofilm of the oral cavity?
Biofilm of the oral cavity: What is it?
We used to call it a plaque, a soft sticky coating containing food particles and bacteria that continuously forms on the surface of the teeth and gums. But now it is already clear that this plaque is much more complicated than previously thought. The best definition of biofilm is a specific, but highly variable structure, consisting of microorganisms and products of their vital activity, embedded in a highly organized intercellular matrix. Biofilm consists of various microorganisms involved in a wide range of physical, metabolic and molecular interactions. The cooperative nature of the microbial community in biofilms provides the advantage of growth for bacteria, greater resistance to host defenses and antimicrobial agents, which also enhances the pathogenicity of the microbial community.
To understand how to cope with biofilms, we need to understand what it is. Costerton first introduced the term in 1978 to emphasize that bacteria combine into a «living film» that interacts with their surroundings. The biofilm is formed on virtually any surface that is in a naturally moist environment. Bacterial bacteria have new properties that are not characteristic of bacteria in the planktonic state. Physiologically, the biofilm bacteria differ from plankton cells that move freely in body fluids: saliva or blood. Biofilm formation is a complex process that undergoes several different phases
The process begins with the adsorption of an adhesive film of bacteria and host molecules on the tooth surface. This is followed by the passive transport of bacteria, mediated by weak long-range attraction forces. These forces are covalent to hydrogen bonds, therefore lead to irreversible attachment of microorganisms to the surface. Further biofilms are formed by autoaggregation of bacteria of one species and coaggregation between heterogeneous species of bacteria, which leads to the functional organization of all microorganisms in the structure. The microclimate changes from aerobic to facultative-anaerobic with the corresponding bacteria secreting the extracellular matrix of biofilms.
In the future, the maturation process of biofilm involves the introduction of new types of bacteria and the formation of a complex community. After maturing, parts of the biofilm are disconnected and scattered to other parts of the oral cavity, forming a new biofilm or influencing the body. Biofilms are formed during a 2-3-day period. This means that with the condition of professional hygiene and home cleaning, recovery is fairly quick. In addition, biofilm can differ in composition in different places of education, even if it is adjacent pockets, which complicates its elimination
Slime covering the biofilm provides maximum protection of bacteria from the antibacterial mechanisms of the host and other «toxic» agents, such as antibiotics and antiseptics. The overall sensitivity observed in bacteria in biofilms also increases resistance to external influences. Through general sensitivity, genetic regulation of antibiotic resistance can provide protection for bacterial biofilms. In addition, the bacterial community can influence its species composition, supporting the growth of the necessary microorganisms, preventing the growth of competitors.
How can I manage the biofilm?
Mechanical cleaning of periodontal pockets removes only 50% of the biofilm present. But its repeated growth occurs within three hours with a 4-fold (400%) increase in the weight of the biofilm. And since the contents of the pocket are not available for hygiene with a brush and thread, the effect of home hygiene is uncertain, regardless of the degree of diligence of the patient. The bristles of the toothbrush are unable to penetrate more than 3 mm into the gingival pocket and can not mechanically affect the biofilm located deeper. Similar problems arise with irrigators.
Irrigation of the bottom of the pocket on all teeth is technically difficult, and most patients do not apply it daily. Even if the biofilm is removed mechanically, the bacteria multiply so quickly that it can not be controlled. The structure of the biofilm after its removal is restored within two days and becomes even more complicated.
Doctors need to cooperate with patients and use a technique that is convenient for them to use, but is effective against biofilm, reaching the bottom of the pockets and thus preventing its re-growth. Antibiotics are extremely limited for this task. Bacterial bacteria are 1000 times more resistant to antibiotics than planktonic form. The use of antibiotics systemically, in the form of rinses or appliques, is not able to eliminate or adequately control the biofilm bacteria. This is important for both natural teeth and for periodontal problems around implants leading to peri-implantitis.
It is known that chlorhexidine affects a young biofilm, but the bacteria of a mature film are more resistant to its effects. Hydrogen peroxide, on the contrary, is reliably effective not only in eliminating biofilms, but also prevents its reformation without the formation of resistance, which is characteristic of other methods of treatment.
The use of hydrogen peroxide was studied daily up to 6 years without side effects or carcinogenic activity, a significant decrease in biofilm and improvement of wound healing, reduction of gingival hemorrhage was shown. Moreover, it has not recorded allergic reactions and the formation of resistance of bacteria. Peroxide destroys the mucus matrix of biofilms and the walls of bacterial cells, essentially «exfoliating» the film layer by layer. This is due to the irreversible destruction of protein chains to amino acids.
Peroxide destroys the protein pellicle that attaches biofilm to the tooth surface, and reduces inflammation in the pocket, by inhibiting interleukin-8 mRNA. Oxygen is required for successful wound healing, as the need for it in reparative processes increases: cell proliferation, angiogenesis, collagen synthesis — peroxide supplies oxygen for repair processes. In addition, oxygen requires the growth of new cells, incl. new vessels. They also bring oxygen-enriched blood to the wound, starting healing. As a result, a new granulation tissue enriched with oxygen is better vascularized. This leads to the formation of more elastic collagen fibers.
Destruction of biofilm by hydrogen peroxide
Multiple scientific studies publish data on the ideal concentration of hydrogen peroxide of 1.7%, as it destroys the biofilm and almost does not cause tissue irritation, characteristic of higher concentrations. The problem is delivering peroxide to the bottom of the periodontal pocket and exposing it there for the duration of exposure to biofilms. Physiologically, the liquid in the pocket is constantly secreted for the elimination of bacteria.
It, unfortunately, washes away all the drugs used to irrigate the pocket. Normally, the cervical fluid is replaced 40 times per hour. In inflamed tissue, the production of the gingival fluid can be increased 30-fold. This leads to an extremely rapid washout of any locally used preparations from the gingival pocket. And since the hydrogen peroxide gel needs some time to contact, inserting it into the pocket with an irrigation syringe is not effective because of the gingival fluid current and is too time-consuming for the patient.
It was determined that a 10-minute exposure of 1.7% of the hydrogen peroxide gel leads to penetration of the matrix mucus and destruction of the cell wall of the biofilm bacteria. Being in the periodontal pocket, peroxide releases oxygen, changing the subgingival microclimate, which makes survival of anaerobic bacteria difficult. As the microorganisms’ habitat changes, the matrix that binds the biofilm collapses, then deep-seated bacteria get under the influence of oxygen.
To cure periodontal disease, peroxide must penetrate to the bottom of the pocket and be there for a sufficient amount of time to act on the biofilm. Studies have shown that rinsers and other hygiene products with peroxide can not be effective for delivering the substance deep into the periodontal pocket to influence the infection.
Сообщение The idea of a biofilm of the oral cavity появились сначала на Имплантация зубов.