Dental Plaque Biofilm PDF

Dental Plaque Biofilm Oral and Dental Sciences Rhona Mann Intended Learning outcomes By the end of the session students should be able to: Define dental plaque as biofilm Classify dental plaque and its varying locations Describe the formation of dental plaque biofilm Explain the role of...

Dental Plaque Biofilm Oral and Dental Sciences Rhona Mann Intended Learning outcomes By the end of the session students should be able to: Define dental plaque as biofilm Classify dental plaque and its varying locations Describe the formation of dental plaque biofilm Explain the role of the ‘extra-cellular slime layer to ensure bacterial colony survival Describe the contents of dental plaque biofilm Explain the most common dental disease caused by dental plaque biofilm Discuss bacterial virulence factors Discuss the most appropriate methods for dental plaque biofilm removal  Definition of Dental Plaque through time now known as BIOFILM ‘Bacterial aggregations on the teeth or other solid oral structures’ ‘Soft deposits that form a biofilm adhering to Lindhe, 2003 the tooth surface or other hard surfaces in the oral cavity, including removable & fixed restorations.’ Bowen, 1976 ‘A specific but highly variable structural entity, resulting from sequential colonisation of micro-organisms on tooth surfaces, restorations & other parts of the oral cavity, composed of salivary elements like mucin, desquamated epithelial cells, debris, micro-organisms, all embedded in extracellular gelatinous matrix’ WHO, 1961 Bacteria Accessed from www.yourdentistryguide.com Accessed Google Feb 2020 2024 This subject is linked to the following subjects Pathogenesis Why Classification of periodontal treatment Inflammation of Periodontal disease may fail disease Year 2 – Caries Fissure Caries Dental Management sealants Specialities Dental Plaque Biofilm – most common dental diseases Accessed from Choice Dental Accessed from The Conversation Feb 2021 Feb 2021  Coronal Classification of Dental Plaque Biofilm Supra- 1 Marginal Gingival Classification Fissural of Dental Plaque Biofilm What is the Tooth difference in Attached environment 2 between supra & Sub- Unattached sub that would gingival influence dental plaque Tissue attached composition? Classification of Dental Plaque Biofilm Tooth attached Unattached Tissue attached Accessed Sharenet Feb 2020 Biofilm Definition ‘Biofilm consists of one or more communities of micro-organisms embedded in glycocalyx ( glycoprotein matrix) , that are usually attached to solid surface’ Costerton et al 1994 Accessed Tanninaquatics Feb 2021 Accessed Live Science Feb 2021 Accessed Review of contact lenses Feb 2021 Formation of Dental Plaque Biofilm  Initial attachment of bacteria to pellicle Four phases of Initial colonisation of the dental tooth surface – new bacteria join plaque biofilm Secondary colonisation: formation Extracellular slime layer formation Mature biofilm – mushroom shaped colonies Free-floating bacteria Biofilm formation begins when free-floating bacteria come in contact with an appropriate surface ‘put down roots’ Where is the bacteria floating? Accessed Giphy Feb 2021 Initial attachment of bacteria to pellicle Pellicle is laid down within a few hours of cleaning A thin coating of salivary proteins that attach to the tooth surface Protection of enamel from acid Double sided adhesive tape Accessed Google Feb 2021 Primary Colonisers Streptococcus sanguis Streptococcus mutans Streptococcus salivarius Accessed Google Feb 2021 Initial colonisation of the tooth surface – new bacteria join Can attach to surfaces & each other Attachment activates different genes and mediate intercellular communication – Quorums sensing (Prosser 1999). Salivary pellicle Tooth surface Quorum Sensing ( or Quorum Signalling) Process of cell to cell QS …used by bacteria to form communication. biofilms. Allows bacteria to detect and respond to cell population density by gene regulation, typically as a means of acclimatising to environmental disadvantages Secondary colonisation: Extracellular slime layer formation Production of extracellular slime layer Primary facultative colonisers start to deplete oxygen – making rooms for anaerobes Secondary colonisers attach to primary colonisers – coaggregation The growing bacteria grow away Salivary pellicle from the tooth Tooth surface Bacterial Bloom – periods of accelerated bacterial growth Mature biofilm – mushroom shaped colonies Mushroom shaped colonies Allows for self-survival Fluid Channels Allows for own food supply and sewage system Salivary pellicle Tooth surface Extra-cellular Slime Layer Protective barrier that surrounds the colony Fluid Channels: Penetrate slime layer Provide nutrients, O2, movement of metabolites, waste products & enzymes Communication system – chemical Accessed Ghostbusters Feb 2021 signals Now visualise Accessed Slide Share Feb 2021 Accessed Edward Byrne Feb 2021 So........ Why does plaque forms in the areas it does? Where on the crown are you least likely to see plaque? Accessed Pinterest Feb 2021 Supra vs Sub Which came first? Difference in environment? Difference in bacteria? Accessed DentalCare Sources of nutrition? Feb 2021 Shape? Composition of Dental Plaque Biofilm Composition of Dental Plaque Biofilm Organic Micro-organisms Polysaccharides Proteins Bacteria Facultative Anaerobic Glycoproteins Gram +’ve Strep. mutans Strep. sanguis Lipids A. viscosus Intra-cellular Matrix Gram –’ve A. actinomycet P.gingivalis Inorganic emcomitans Calcium Ekinella F.nucleatum corrodens Sodium P.intermedia Phosphorous Spirochetes T.denticola Potassium Accessed Edward Byrne Feb 2021 Micro-organisms and Oral Disease Bacteria Associated with Periodontal Disease Porphyromonas Aggregatibacter Treponema denticola gingivalis actinomycemcomitans Accessed Jornal Dentistry & Perio expertiseFeb 2021 Bacteria Associated with Caries Streptococcus mutans Lactobacilli Accessed Facebook Feb 2021 Accessed Nutraceutical Feb 2021 Bacterial Virulence Factors Refer to Virulence Factors lecture Mechanisms that enable biofilm to colonise, invade & damage tissue – VIRULENCE FACTORS Can be structural characteristics of bacteria itself or substances produced Removal of Dental Plaque What challenges do you face? Have you had someone reach for mouthwash to remove plaque? How do you explain it to a patient? How are you going to remove it? Accessed Edward Byrne Feb 2021 Physical Plaque Removal Contact with biofilm Friction Accessed Telegraph Feb 2021 Physical removal What will that do? Accessed Preferred dental care Feb 2021 Further reading https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2147593/ https://link.springer.com/article/10.1007/s10266-006-0063-3