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