Plaque Formation and Composition
- Dental plaque is a biofilm that attaches to tooth surfaces, restorations, and prosthetic appliances if left undisturbed.
- An acquired pellicle is a layer of saliva that forms shortly after cleaning the teeth or exposure of new teeth.
- Bacteria attach to the pellicle layer, form micro-colonies, and mature on the tooth, leading to oral diseases.
- Biofilm formation involves six steps, including pellicle formation, bacterial attachment, micro-colony formation, maturation, detachment, and reattachment.
- Different types of bacteria and immune cells are present in the mouth and contribute to oral health.
- Approximately 80-90% of plaque's weight is water, while bacteria make up 70% of the dry weight.
- The remaining 30% consists of polysaccharides and glycoproteins.
- Polysaccharides and glycoproteins contribute to the structure and adhesion of plaque.
- The composition of plaque can vary based on location in the mouth and individual factors.
Bacteria and Biofilm
- Streptococcus mutans and other anaerobes are the main microorganisms that form the biofilm.
- S. mutans uses sucrose to produce a sticky polysaccharide that allows bacteria to cohere, forming plaque.
- Failure to remove plaque allows bacteria to proliferate and cause dental diseases.
- The bacterial composition of plaque changes during different stages of formation.
- Early biofilm primarily consists of Gram-positive cocci, while older biofilm contains more complex flora with rods and filamentous forms.
- Dental plaque is considered a biofilm adhered to the tooth surface.
- It is a microbial community organised to a specific structure and function.
- Plaque is rich in species, with approximately 1000 different bacterial species identified.
- Salivary pellicles act as an adhesive, allowing bacteria to attach and grow on the tooth surface.
- Early colonizers pave the way for late colonizers, leading to the formation of a mature biofilm.
Supragingival and Subgingival Biofilm
- Supragingival biofilm forms above the gums and is the first type of plaque to form after brushing.
- It consists mainly of aerobic bacteria but can develop anaerobic bacteria if not removed.
- Subgingival biofilm is located under the gums and is mostly composed of anaerobic bacteria.
- It forms when supragingival biofilm grows downward into the gum pockets.
- The extracellular matrix of biofilms contains proteins, polysaccharides, and lipids.
Consequences of Plaque Build-up
Gingivitis:
- Inflammatory lesion localised to the gingival tissue
- Result of plaque build-up around the gingival tissues
- Bacteria in biofilm elicit a host response, causing localised inflammation
- Cardinal signs of inflammation include red, puffy gums and bleeding
- Reversible with plaque removal, but can progress to periodontitis if left untreated
Periodontitis:
- Infection of the gums leading to bone destruction around the teeth
- Occurs after gingivitis, not all individuals with gingivitis develop periodontitis
- Plaque accumulation is vital for progression, as bacteria release enzymes that attack bone
- Treatment includes strict oral hygiene and surgical debridement by a dental professional
- Can contribute to systemic diseases and conditions when bacteria spread through the body
Caries:
- Infectious disease caused by bacteria, primarily Streptococcus mutans
- Acid demineralization of enamel, leading to breakdown of inner dental tissue
- Susceptibility depends on individual risk factors and preventive factors
- Factors include low fluoride exposure, sugar consumption, tooth cleaning, and saliva flow
- Organic acids released from plaque cause demineralization and tooth decay
Detection, Treatments, and Related Topics
- Two main methods of detecting plaque build-up: plaque disclosing gel and visual/tactile detection
- Mouthwash with alcohol may not be the best option for controlling plaque accumulation
- Essential oil mouthwashes have been developed as an alternative
- Research on their effectiveness is ongoing, with mixed results
- Lemongrass essential oil mouthwash shows antimicrobial properties as a substitute for alcohol
- Mouthwash containing essential oils and ethyl lauroyl arginate has been found to inhibit plaque and gingivitis
- The canine and feline oral microbiomes have been investigated, revealing insights into the microbial composition
- Flossing is an important part of oral hygiene for removing plaque and preventing dental diseases
- Gingiva, dental disease, and oral microbiology are related topics that contribute to understanding plaque formation and identification
Dental plaque is a biofilm of microorganisms (mostly bacteria, but also fungi) that grows on surfaces within the mouth. It is a sticky colorless deposit at first, but when it forms tartar, it is often brown or pale yellow. It is commonly found between the teeth, on the front of teeth, behind teeth, on chewing surfaces, along the gumline (supragingival), or below the gumline cervical margins (subgingival). Dental plaque is also known as microbial plaque, oral biofilm, dental biofilm, dental plaque biofilm or bacterial plaque biofilm. Bacterial plaque is one of the major causes for dental decay and gum disease.
Progression and build-up of dental plaque can give rise to tooth decay – the localised destruction of the tissues of the tooth by acid produced from the bacterial degradation of fermentable sugar – and periodontal problems such as gingivitis and periodontitis; hence it is important to disrupt the mass of bacteria and remove it. Plaque control and removal can be achieved with correct daily or twice-daily tooth brushing and use of interdental aids such as dental floss and interdental brushes.
Oral hygiene is important as dental biofilms may become acidic causing demineralization of the teeth (also known as dental caries) or harden into dental calculus (also known as tartar). Calculus cannot be removed through tooth brushing or with interdental aids, but only through professional cleaning.