DENTAL BIOFILM
I – Definition
According to MOUTON and ROBERT in 1994, dental biofilm is defined as a heterogeneous accumulation, adherent to the surface of the teeth or located in the gingivo-dental space; it is also found on the various dental restoration materials as well as on prostheses. It is composed of a microbial community, rich in aerobic and anaerobic bacteria, coated in an intercellular matrix of polymers of microbial and salivary origin.
II. Formation of dental plaque
1 –Mechanism of adhesion
a – Exogenous acquired film (EAP)
After prophylactic enamel brushing, salivary proteins bind within minutes to form PAE. These proteins then interact by establishing cross-links between several of them.
Biologists have described it as a soft, colorless, translucent film distributed diffusely over the crown in somewhat higher amounts near the gingiva.
b – Molecular interactions between bacteria and PAE
Bacteria are transported to the tooth surface by saliva. Once near the tooth, the negatively charged bacteria adhere reversibly to the PAE.
This PAE itself is charged by the interaction of repulsive electrostatic forces and attractive Van Der Waals forces.
The irreversible adhesion of the first bacteria (Streptococcus goidoniti, oralis and mitis; Actinomyces viscosus) on the PAE is done by specific protein-protein type interactions.
c – Co aggregation
As plaque grows, only bacteria that can survive anaerobically will be able to remain in contact with mineralized dental tissues. Bacteria present in the young dental biofilm can transform sucrose into extracellular polymers with glycan sequences. Glycan interactions are then formed that contribute to consolidating the biofilm, making it denser, and thus putting the bacteria closest to the dental surface in a state of anaerobiosis.
III – Composition of dental biofilm
Dental biofilm is mainly composed of bacteria distributed in heterogeneous and homogeneous zones forming microcolonies. Dental biofilm appears as a stack of bacterial colonies separated by channels inside an extracellular matrix. Among these bacteria, some settle very early (streptococci, in particular: S. oralis, mitis, goidoniti), others have a preponderant role (f. nucleatum) because they act as a bridge between the colonizing bacteria at the beginning of the formation of the biofilm and those that adhere later (A. actinomicetem comitans, P. gingivalis, Spirochetes, P. intermedia, etc.).
IV-Clinical aspects and distribution of plaque
Clinically, visualization of plaque is only possible if the plaque is of a certain thickness; it then appears as a yellowish-white coating located first along the gingival margin.
At the beginning of its installation or it is present in small quantities, the plaque is difficult to highlight, in this case, we try either to scrape the surface of the tooth along the gingival margin with the tip of a probe, or by using a revealing solution. This revealer can be either a conventional staining dye for plaque (erythrosine, fuchsine), or a fluorescent dye (such as fluorescence) that can be visualized by illuminating it with ultraviolet light. Plaque deposits can be found in the fissures of occlusal surfaces, in the dimples, on smooth dental surfaces, fillings and prosthetic restorations and more particularly on poorly adjusted crowns as well as on orthodontic appliances and removable prostheses.
V – Classification of the plate
1 – Above-gingival plaque
It is located at the level of the dental crown, the first germs will attach themselves and multiply on the surface, sometimes on the enamel directly but most often on the acquired film.
2 – Subgingival plaque
It is located in the gingival sulcus, and it continues the supragingival plaque, the adhesion of new germs of the oral flora ensures the progression of the plaque towards the gingival sulcus. The plaque remains attached along the roots and gradually creates the pocket. The limit separating these two types of plaque is not constant, sometimes due to gingival growth, sometimes due to gingival migration in the apical direction during a recession.
VI – Elements promoting plaque retention
1 – Carious lesions
Subgingival carious lesions constitute favorable niches for the growth of microorganisms, especially anaerobic ones; brushing alone in this case is insufficient.
2– Morphological and functional anomalies
- Anomalies
- of position
- of shape
- functional (tooth without antagonist)
- Lack of point of contact
- Inadequate gingival morphology
3 – Iatrogenic factors
- No restoration of contact points
- Poorly designed prosthesis
- Overflowing fillings, overbite
4 – Role of saliva in plaque formation
Saliva contains a mixture of glycoproteins called: “MUCIN”
Salivary glycoproteins consist of proteins combined with various carbohydrates. Enzymes (glycosidases) produced by oral bacteria break down the carbohydrates they feed on.
5 – Influence of diet on plaque formation
Diet plays an important role in the development of dental plaque. Diet can affect plaque formation in two ways, either through its consistency or through its composition.
a – Consistency of the diet: A hard and fibrous diet hinders the formation of plaque. The plaque located along the gingival margin and in the interdental spaces is not subjected to the friction of food during chewing
b – Composition: Dietary composition was considered to have an important influence on plaque formation because both diet and saliva provide nutrients to plaque microorganisms.
VII – Fight against dental plaque
1 – Plaque control
Plaque control aims to prevent plaque and other deposits from building up on tooth and gingival surfaces. The safest way to control plaque is through mechanical cleaning with a toothbrush, toothpaste, and other cleaning instruments.
a- Tooth brushing method
There are various methods of brushing
- Stillman or Modified Stillman Method
- Bass method: used to remove soft deposits located beyond the gum line
- Charters method: used in the case of gingival recessions
- Roller method
b – Brushing methods
- Manual or electric toothbrush
- Dental floss
- Rubber tip
- Interdental sticks or wooden toothpicks
- Interdental bumps
Conclusion
Dental biofilm is considered to be the initial factor in the development of periodontal disease. The only way to significantly delay the progression of periodontal disease is to introduce oral hygiene measures.
DENTAL BIOFILM
Deep cavities may require root canal treatment.
Dental veneers correct chipped or discolored teeth.
Misaligned teeth can cause uneven wear.
Dental implants preserve the bone structure of the jaw.
Fluoride mouthwashes help prevent cavities.
Decayed baby teeth can affect the position of permanent teeth.
An electric toothbrush cleans hard-to-reach areas more effectively.