Physiological dental formations
Before pathogenic deposits appear on hard tissues, natural protective structures are formed. These include:
- Cuticle — an organic structureless membrane representing the remnant of the outer enamel epithelium. It is closely connected with the enamel prism membrane and completely covers the crown only in a newly erupted tooth. Over time, the cuticle wears off in areas subject to mechanical stress.
- Pellicle — the primary barrier, an unstructured acellular film made of salivary glycoproteins. It forms over a period ranging from a few minutes to two hours. The role of the pellicle is twofold: in addition to a protective function, it actively accumulates food debris and microorganisms, serving as a basis for further deposits.
Types of soft deposits
Non-mineralized accumulations are divided into non-pigmented (food debris, deposits) and pigmented. Of greatest clinical significance are two types of non-pigmented formations:
| Characteristic | Soft white dental plaque | Dental plaque (Macula dentalis) |
|---|---|---|
| Structure and fixation | Structureless, easily displaced | Structured, sticky, firmly fixed |
| Visualization | Visible to the naked eye without indicators | Transparent, requires staining with solutions |
| Formation features | Forms predominantly at night, causes halitosis | Forms on top of the pellicle, covered with a mucoid layer |
| Composition | Food, microbes, breakdown of epithelium and leukocytes | Bacteria, matrix (matrix), saliva, metabolites, macrophages |
The microbial landscape of dental plaque includes streptococci, vibrios, bacilli, and actinomycetes.
Stages of dental plaque formation (according to H.P. Müller)
The maturation process of Macula dentalis is accompanied by a predictable shift in microflora:
- Initial stage: formation of the pellicle.
- Day 1: adhesion of gram-positive cocci. Bacteria produce extracellular polysaccharides, leading to the smoothing (leveling) of enamel irregularities.
- Days 2–4: change in the microbial landscape. The proportion of streptococci drops, active growth of anaerobic and facultative actinomycetes, as well as gram-negative rods and cocci, begins.
- After a week: spirochetes and motile rods join the association.
Pigmented deposits
Deposits can acquire various colors under the influence of external and internal factors. Dense dark deposits are most often localized in the cervical third of the crown, following the contour of the gingiva.
- Brown and black color: characteristic of smoker's plaque. Black pigmentation may also indicate excess iron in blood serum.
- Green and brown color: the result of the life activity of chromogenic bacteria.
- Yellow color: caused by the presence of bile pigments in the gingival fluid.
- Various shades: arise due to food pigments and medicinal colorants.
Pathogenic role and diagnosis
Microorganisms in non-mineralized deposits release acids that lower the pH and trigger enamel demineralization — the initial stage of dental caries. Subsequently, bacterial breakdown of organic substances occurs, and a visible cavity is formed.
The accumulation of microbes under the gingiva causes tissue intoxication by enzymes. The development of periodontal pathology proceeds in stages:
- Dental deposits.
- Gingival inflammation.
- Microbial invasion.
- Infection of the root cementum.
- Bone resorption.
Clinical significance depends on plaque localization. Supragingival plaque contributes to caries and gingivitis, whereas subgingival plaque is colonized by anaerobes and leads to periodontitis (formation of deep pockets, gingival recession, and tooth mobility).
To detect deposits, visual methods, staining with dyes (qualitative and quantitative), and instrumental diagnostics are used. Single-ended and double-ended explorers — instruments with a curved, pointed working part — are used for probing.
Briefly: answers to topical questions
Which specific microorganisms cause the formation of green pigmented plaque?
- Chromogenic bacteria (chromogenic bacteria) — microorganisms that cause the appearance of green or brown pigmented plaque on teeth.
To memorize the shift in plaque microflora: on Day 1, Cocci rule, from Days 2–4 Actinomycetes join in, and after a week Spirochetes arrive. This yields the abbreviation C–A–S.
Class and exam questions
How does soft dental plaque differ from dental biofilm (dental plaque)?
Soft debris lacks a distinct structure, is easily removed, and is visually apparent. Dental plaque is tightly adhered (cohesive), has a complex matrix, and is entirely transparent—special disclosing agents are required for its detection.
Why do dental deposits cause periodontitis?
The reaction of the marginal gingiva to plaque leads to edema and deepening of the gingival sulcus. This creates conditions for the growth of subgingival plaque, colonization by anaerobic bacteria, and destruction of the connective tissue attachment of the tooth.
How are soft deposits and dental calculus related?
Soft plaque and dental plaque are obligatory precursors of calculus. Under the influence of minerals from saliva or gingival fluid, plaque calcifies, but a layer of non-mineralized bacteria always remains on its surface.
What else to study on this topic
- Stages of dental plaque calcification: transformation into supragingival and subgingival calculus.
- The influence of individual calculus formation rate on the state of the tooth-supporting apparatus.
- Features of using dental explorers for diagnosing enamel defects and fillings.
- Pathogenesis of secondary infection of the oral mucosa against the background of dysbiosis.
- Mechanism of enamel demineralization by acid-producing dental plaque bacteria.
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Other topics in "Chapter 13. Dental Deposits"
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