Aetiology and Pathogenesis of Periodontitis Flashcards
What is the primary cause of inflammatory periodontal disease?
plaque
What are local plaque retentive factors?
Poor restoration margins
Mouth breathing
Calculus
Crowding
What are systemic modifying factors related to plaque accumulation?
Medication
Sex hormones
What are the characteristics of a healthy gingiva?
Scalloped/knife edged margin Stippled appearance Pink Steady flow of GCF with antibodies Small amount of regulated immune cells Continuous epithelial shedding Intact barrier created by junctional epithelium
What are the characteristics of a disease gingiva?
Altered microbial colonisation Increased GCF flow Influx of immune cells Proliferation and ulceration of the gingiva Vessel dilation = redness Loss of collagen
Describe the characteristics of periodontal disease.
Irreversible loss of attachment:
Apical migration of junctional epithelium
Bone loss - presence of more plasma cells (than in gingivitis)
What is a true pocket?
Apical migration of the junctional epithelium = loss of attachment
What is a false pocket?
Ulceration and proliferation of the gingiva - NO loss of attachment
Does gingivitis always progress to periodontitis?
No, if the plaque and plaque retentive features are removed the gingiva should return to health.
Describe the type of progression that is involved in periodontitis.
Episodic
What is the average loss of attachment per year in periodontitis?
0.05mm to 0.1mm
THIS IS HIGHLY VARIABLE
What is the definition of a biofilm?
One or more communities of microorganisms embedded in a glycocalyx which attaches to a solid surfaces
Does plaque form a biofilm?
Yes
What are the properties of biofilms?
Provides protection
Facilitates nutrient exchange and the removal of waste.
Communicated between bacteria
Establishes the correct physiochemical environment
Which bacteria are heavily associated with periodontal disease?
P. Gingivalis
B. forsythus
T. Denticola
Increased numbers are diseased sites
Decreased numbers at sites after receiving periodontal therapy
In terms of the immune response, what causes attachment loss via apical migration of the junctional epithelium?
MMPs secreted by host inflammatory cells
In terms of the immune response, what causes bone loss?
Osteoclasts
What role do neutrophils have in the inflammatory repose of periodontal disease?
Maintains healthy periodontium
Increase in numbers and act as reactive oxygen species to trap and destroy bacteria - fight and contain.
However these reactive oxygen species can also cause harm to the host when there is excessive infiltration in periodontitis = predispose to disease
Describe the immune response in an early periodontal lesion.
T lymphocytes initially
B cells and plasma cells enter at a later stage
Antibody is produced locally - prevents the infection from becoming systemic.
What are the 3 types of bone loss?
Horizontal - bone CANT be regenerated
Vertical/angular (bone level lower on one side) - bone CAN be regenerated
Furcation
Where is horizontal bone loss common?
In narrow alveolar bone
What are the general risk factors of periodontitis?
Smoking Diabetes Nutrition Medication Systemic disease Stress
What effect does smoking have on the gingiva?
Increases vasoconstriction of the gingival vessels
Increases keratinisation of the gingiva
Increases pro-inflammatory cytokines
Impairs antibody function
What are local risk factors for periodontitis?
Anatomical features: Enamel projections Grooves Furcations Gum recession
Iatrogenic damage Restoration overhangs Defective crown margins Orthodontic appliances Poorly adapted RPD
Tooth position Crowing Malalignment Tipping Migration
