Aetiology and Pathogenesis Flashcards
What are local plaque retention factors? (4 points)
- Calculus
- Restoration margins
- Crowding
- Mouth breathing
What are systemic modifying factors for plaque/gingivitis? (2 points)
- Sex hormones
- Medication
What characteristics define gingival health? (3 points)
- Knife edge, scalloped gingival margin
- Stippling (in about 30%)
- Pink
What are defining features of periodontitis? (2 points)
- Irreversible loss of attachment of the epithelium
- Bone low
Does gingivitis always progress to periodontitis?
- No
- But it can and in many cases will
Once periodontitis is initiated, is progression of the attachment loss episodic or continuous?
- Can be either
- Hard to judge how fast it goes once initiated
- Different sites within the same mouth may be affected to markedly varying degrees
What is the rate of progression loss of attachment in periodontitis like?
- Generally very slow (0.05-0.1mm per year) but this is highly variable
What is biofilm?
- One or more communities of microorganisms, embedded in a glycocalyx, attached to a solid surface
What are 4 properties of biofilm?
- Provide protection for colonising species from competing organisms and environment (host defences, antibiotics)
- Facilitate uptake of nutrients and removal of metabolic products
- Development of appropriate physiochemical environment e.g. pH, O2 concentration
- Communication between bacteria
What 2 features can increase the bacteria’s virulence?
- Ability to colonise and compete in an ecological niche
- Ability to evade host defences
How can bacteria evade host defences? (4 points)
- Degrade host immunoglobin and complement
- Leukotoxin production
- Tissue invasion
- Inhibition of antibody synthesis
Does a specific bacteria cause periodontal disease?
- Not one single bacteria has been proven causative
What is possible evidence needed to prove that a specific bacteria is the cause of something? (5 points)
- Presence in elevated numbers at diseased sites
- Reduced numbers following periodontal therapy
- Presence of an elevated specific immune response
- Production of virulence factors
- Evidence from animal models
Which complex of bacteria makes you likely to have perio problems? (3 points)
- P. gingivalis
- B. forsythus
- T. denticola
Can periodontitis occur without the presence of bacteria ?
- No
Periodontitis is a synergistic infection. What does this mean?
- Not just one bacteria that causes it (plaque ecology is important)
What are examples of mechanisms that contribute to the host response against perio problems? (4 points)
- Saliva
- Epithelium (physical barrier, shedding of cells, production of inflammatory mediators)
- GCF
- Inflammatory and immune responses
Which type of cell is the initial periodontal lesion composed of?
- T lymphocytes
The initial periodontal lesion is compromised mainly of T lymphocytes. Which cells predominate in a later stage? (2 points)
- B cells
- Plasma cells
Antibody is produced locally at the initial periodontal lesion. What is its likely role?
- Likely protective role
What are the protective functions of an antibody? (4 points)
- Inhibition of adhesion/invasion
- Complement activation
- Neutralisation of toxins
- Opsonisation and phagocytosis
What are MMP’s? (2 points)
- Matrix metalloproteinases are a family of zinc and calcium dependent proteolytic enzymes, which include collagenases
- In periodontitis, Matrix degradation is largely a result of MMP’s secreted by host inflammatory cells
What are general risk factors of periodontitis? (6 points)
- Smoking
- diabetes
- stress
- Drugs
- Systemic disease
- Nutrition
What are risk determinants of periodontal disease? (3 points)
- Genetics
- Socioeconomic status
- Gender
