Periodontology Flashcards
Describe the appearance of healthy gingiva.
- knife edge, scalloped gingival margin
- stippling
- pink
What is clinical gingival health?
- < 10% bleeding sites
- probing depths < or = 3mm
- intact periodontium, absence of bleeding and swelling, absence of bone loss
Describe the appearance of gingivitis.
- red inflamed gingiva
- loss of knife edge margin
- smooth, shiny gingiva
- bleeding on probing
What is clinical gingivitis?
- bleeding on probing > 10% but <30%
- pocket depth is not greater than 3mm
- no attachment or bone loss
- clinical changes are reversible
Describe the appearance of periodontitis.
- gingiva inflamed
- gingival margins receded
- teeth appear longer / root visible
- spacing
What is clinical periodontitis?
- pocket depths > 3mm
- bleeding on probing
- loss of periodontal attachment
- loss of alveolar bone
- irreversible
What is the difference between a true and a false pocket?
- false pocket occurs when the sulcular epithelium proliferates due to irritation caused by plaque, the gingiva becomes inflamed, therefore the probe will “disappear into pocket”, but there is no actual attachment loss
- true pocket occur when there is attachment loss, and the probe can be seen to sink into the pocket
What is the normal distance from the cemento-enamel junction to the alveolar bone ?
- 1-2mm
- can be observed on radiographs
Describe horizontal bone loss.
- bone loss in a consistent, flat pattern between teeth
Describe vertical or angular bone loss.
- bone loss is not consistent between teeth
- bone loss is greater on one side than the other between two teeth
- “deep angular defects”
What affects the chance of horizontal versus vertical bone loss?
- narrower sections of alveolar bone between teeth are more likely to result in horizontal bone loss
- this is because when plaque migrates apically it has a “2mm zone of destruction”, therefore can wipe out a narrower pieces of bone
- vertical bone loss is caused when the alveolar bone between teeth is wider than this zone of destruction, so remains intact on the neighbouring tooth
Describe furcation bone loss.
- bone loss between the root functions
- different grades, from 1-3
- grade 3 is a through and through furcation
How much attachment loss is considered rapid progression of periodontitis?
- greater than or equal to 2mm over 5 years
What is the keystone pathogen of periodontitis?
- p gingivalis
- changes the behaviour of the biofilm
Describe the microbial balance and immune response in gingival health.
- symbiosis
- proportionate immune response
Describe the microbial balance and immune response in gingivitis.
- dysbiosis
- proportionate immune response
Describe the microbial balance and immune response in periodontitis.
- dysbiosis
- disproportionate immune response
= this results in soft and hard tissue loss
What is involved in the innate host immune response of periodontitis?
- saliva
- epithelium, which acts as a physical barrier, sheds cells and produces inflammatory mediators
- gingival crevicular fluid (GCF)
- inflammatory and immune responses
What are MMPs?
- matrixmetalloproteinases
- degradative enzymes that are released by host inflammatory cells
What is involved in hard tissue destruction?
- the immune cell activation of osteoclasts (RANK/RANKL/cytokines)
What are local risk factors for periodontitis?
Anatomical - grooves - furcation - gingival recession Tooth position - malalignment or crowding - migration - occlusal forces Iatrogenic - restoration overhangs - orthodontic appliances - dentures - defective crown margins
How does smoking affect periodontitis?
- vasoconstriction of gingival vessels
- increased keratinisation of the gingiva
- impaired antibody production
- affects t-cell and neutrophil function
- increased production of pro-inflammatoty cytokines which increase speed of tissue destruction
How does smoking affect the assessment of the gingiva?
- due to vasoconstriction the gingiva do not appear as inflamed
- no bleeding on probing
How do genetics affect periodontitis?
- affects around 50% of cases
- polymorphisms for increased IL-1 production predispose someone to periodontitis
What is GCF?
- gingival crevicular fluid
- released in greater quantities during disease
- contains AMP, cytokines, chemokines, lactoferrin, IgG
What virulence factors benefit p gingivalis?
- asaccahrolytic, breaks down proteins for energy
- proteases (gingipans) degrade host proteins for energy
- atypical LPS (endotoxin) blocks the host signalling through TLR 4 receptors
- inflammophillic means that it thrives in inflammatory conditions
Describe the process of gingivitis.
- TLRs detect an accumulation of plaque
- increased activation of TLRs = increased production of pro-inflammatory mediators eg AMPs, cytokines
- clinical signs of inflammation, caused by increased cell migration
What are TLRs?
- toll-like receptors
- they are pattern recognition receptors that stimulate the innate immune system
What role do neutrophils play in gingivitis?
- degradative enzymes including MMPs
What role do monocytes play in gingivitis?
- differentiate into macrophages and phagocytose
What role do lymphocytes play in gingivitis?
- t-cells coordinate the response
- b-cells release antibodies into the GCF
What cytokines are involved in bone formation and resorption?
- RANKL, stimulates osteoclasts to resorb bone, produced by activated T and B cells
- RANK, receptors for RANKL on the osteoclasts
- OPG, RANKL inhibitor
What is the relationship between RANKL and OPG during periodontitis?
- RANKL > OPG
- excess RANKL means that RANK receptors cannot bind with OPG, meaning resorption is uncontrolled
- during inflammation there are higher levels of RANKL and lower levels of OPG
Describe the process of periodontitis.
- activation of TLRs = increased secretion of pro-inflammatory mediators
- activated lymphocytes express RANKL and OPG which disrupt the bone formation/resorption balance
- pro-inflammatory cytokines inhibit bone formation
- elevated and unregulated MMP production results in connective tissue destruction
What is plaque?
- sticky colourless biofilm
- the microbial composition changes between health and disease
What is calculus?
- calcified plaque
- always covered by a layer of plaque biofilm
- can be supra or sub gingival
- calculus acts as a plaque retentive factor