Aetiology of Periodontal Diseases Flashcards
Describe how healthy gums would look
- Pink, firm, scalloped gingival margin with knife-edged papillae
- Free (marginal) gingiva
- Gingiva cuff 1-2mm wide around the neck of the tooth
- external wall of gingival sulcus 1-2mm deep
- mucoperiosteum bound to bone 2hcih splits at mucogingival junction-alveolar mucosa
What does interdental mean?
Between two teeth
What is found between teeth?
Soft tissues called inter proximal or interdental gingiva
what is free gingiva?
Gingiva hat is not attached to teeth or bone
What does free gingiva do?
Forms the wall of the gingival sulcus or crevice
What is the gingival margin?
Knife edged margin
What are the two basic periodontal diseases?
- Gingivitis
- Periodontitis
Both are inflammatory conditions triggered by bacteria
What are the differences between gingivitis and periodontitis?
Both are diseases of the gums but Gingivitis is reversible but Periodontitis is nor irreversible
What is the sequence of events that can lead to periodontitis?
- Supragingival plaque builds up
- This leads to gingivitis
- Crevice deepens (more than 3mm) and plaque extends subgingivally
- Leading to periodontitis
If the gingival crevice depth increases beyond a certain value Gingivitis can become Periodontitis. What is this depth value?
3mm
What is the most common type of gingivitis?
Plaque induced gingivitis
What are some clinical features of Plaque induced gingivitis
- Red, swollen, bleeding gingiva
- Blunting of papillae, loss of contour
- Reversible on removal of aetiological agent, plaque
- False pocket, not associated with bone loss
Name some microorganisms responsible for causing gingivitis
- Actinomyces israelii
- A. naeslundii,
- A.odontolyticus,
- Veilonella parvula,
- Campylobacter spp
Why might false pockets form?
May occur on periodontium with reduced support
Which white blood cell is the first to arrive when plaque accusation increases?
Neutrophiles
What are the 3 key features of periodontitis?
- Loss of periodontal connective tissue attachment
- Apical migration of junctional epithelium
formation of periodontal pocket, lined with pocket epithelium - Alveolar bone loss
What is the eventual result of periodontitis?
Tooth loss
Give some features you would see in a section a tooth which has periodontitis
1, The gingival margin willl be at the top of the pocket
- Neutrophils will migrate
- Clinical attachment loss from the cement enamel junction
- Ulcerates cake epithelium
- Heavy inflammatory infiltrates
- Bone loss and loss periodontal tissue
How do you diagnose periodontitis?
- Can take pocket measurement
2. Take radiographs to see if bone has been loss
How can you measure the pocket depth
Using a probe (usually BPE probes)
You introduce the probe into the sulcus
Record the depth of the probe going into the sulcus
What is the aetiology for periodontal disease?
Microbial plaque is he primary aetiological age in periodontal disease
What is an aetiological agent?
A causative agent
What are some secondary modifying features causing aetiology
- Local factors
2. Systemic factors
How can you see plaque in the mouth?
By using a disclosing tablet
What is plaque?
Complex microbial community in matrix of polymers of bacterial & salivary origin
It is a biofilm
Describe plaque as a biofilm
- A community of micro organism attached to the surface
- Spatial organised into a 3D structure
- Enclosed in a matrix of extra cellular material from cells themselves and the environment
How do we classify plaque?
Can be
- Supragingival
- Subgingival
What is Supragingival plaque?
Plaque found above the gingival margin
ie on the tooth surface
What is Subgingival plaque?
Plaque found below the gingival margin
ie inside the gingival sulcus on the root surfaces
Describe Supragingival plaque
- Mostly made up of gram +ve cocci and rods
- Aerobic unless there’s a thick layer
- Low species diversity
Describe Subgingival plaque
- Mostly made up of gram -ve rods, spirochaetes
- Highly anaerobic
- Great series diversity
How many species have we discovered to be found in the mouth?
600 ish
What makes plaque pathogenic?
They have Virulence (toxic) factors
Name some Virulence (toxic) factors of plaque
- Proteases
- Bone resorbing factors
- Cytotoxic metabolites
- Leukotoxin
- Capsule
- Induction of inflammatory response
What is calculus?
Calcifies plaque due to mineralisation of long term plaque on the tooth
What causes the mineralisation of plaque into calculus?
Minerals in the saliva and gingival crevicular fluid interacting with plaque causing it to calcify
Describe supragingival calculus
creamy yellow colour
it is clearly visible
Where is supraginigval plaque usually found?
Openings salivary ducts as there’s a surplus of minerals at these openings
(buccal side of upper molars and lingua spect of incisors)
Where do salivary glands open?
buccal side of upper molars
Lingual aspect of incisors
Describe subgingival calculus
dark brown or black in colour can’t be seen as it is below the gum line
It is highly adherent
Where is subginigval plaque usually found?
Any subginigval location in the mouth
Mineral salts are from the gingival crevicular fluid
What are the 3 theories explain why calculus deposition occurs
- Precipitation of mineral salts into plaque (occurs 2-14 days after plaque formation)
- Element in plaque acts as a nucleation or seeding site
- Bacterial viability within calculus (Theres a reservoir of bacteria)
What are the 3 plaque hypotheses?
- Non specific (1986)
- Specific (1976,1979)
- Ecological ( 1991, 1994)
Explain the non specific hypotheses of plaque
Theres plaque all over the mouth and all the plaque is responsive for the destruction of periodontal tissue
Explain the specific hypotheses of plaque
Certain bacteria are pathogenic not the entire bacterial microflora
Explain the ecological hypotheses of plaque
Unless there’s a shift in the balance (dysbiosis) due to environmental change plaque will not become pathogenic
If it does become pathogenic then destruction will occur
Which of the 3 plaque hypotheses is the most accepted ?
The ecological
According to the ecological model what happens if the ginigva is healthy?
- Plaque is reduced
- Reduced inflammation
- Low GCF flow
- Higher redox potential (more aerobic)
- predominantly gram +ve microflora
- Mainly facultative anaerobes
According to the ecological model what happens if there is gingivitis?
- Plaque accumulates
- Increased inflammation
- Higher GCF flow
- Lower redox potential (anaerobic)
- predominantly gram -ve microflora
- Mainly obligate anaerobes
What are the host defence in the mouth
- Saliva
- Epithelium
- Inflammatory response
- Immune response
- Mediators
Name the putative periodontal pathogens
- Aggregatibacter actinomycetemcomitans
- Tannerella forsythensis
- Campylobacter rectus
- Eikonella corrodens
- Fusobacterium nucleatum
- Porphyromonas gingivalis
- Prevotella intermedia
- Peptostreptococcus micros
- Spirochaetes
Define risk factors
Characteristic, aspect of behaviour or environmental exposure associated with destructive periodontitis, not necessarily causal
Name some local risk factors associate with periodontal disease
Subgingival calculus
Name some systemic risk factors associate with periodontal disease
- smoking
- poorly controlled diabetes
- stress
