Calculus

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Calculus
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• Dental calculus

• Supragingival
• Friable
• Readily removed by scaling
• Unpigmented
• Form in greatest amounts
• on the lower incisors upper
• molars i.e. near the orifices of
• the main salivary ducts
• Composition varies in
• different sites
• Salivary origin

• b) Subginival
• Harder
• Coloured (often green)
• Present in smaller deposits,
• which are not localized near
• the salivary ducts
• Composition less site
• dependent
• non-salivary (serum) origin

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• Composition of Supragingival Calculus

Organic ( 20)
Inorganic ( 80)

• Derived from saliva
• bacteria
• Largely protein with carbohydrate
• attached (12-20)
• GAG (CS, HA HS) from the
• gingivae
• Lipids (3) perhaps bacterial
• origin

• Brushite
• CaHPO4.2H2O detectable in all
• deposits after 14 days of development

Octa calcium phosphate Ca8 (HPO4)2 (PO4)4
Wetlockite Ca3 (PO4)2 With some magnesium Instead
of calcium
Especially in the presence Of fluoride
apatite
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Composition of Supragingival Calculus - (
continue)

• F is also present at 400 ppm (more in old
  calculus)
• Many filamentous bacteria is present (example
  leptotrichia buccalis)
• Formation is intermittent

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Theories of calculus formation

• Carbon dioxide loss
• CO2 loss from saliva, as it equilibrates
  with low CO2 tension in the month ppt of
  calcium salts
• pH change by ammonia formation
• Urea NH3 pH, thus favoring ppt
  of calcium phosphate

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• The phosphatase theory
• PPi 2Pi
  encourage mineralization of plaque
• not much evidence to this
• Seeding theory
• A seeding process calculus
• This does not explain individual variations in
  formation

Bacterial
pyrophosphatase
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Steps in calculus formation

• Two stages
• Matrix deposition (derived from plaque)
• Mineralization reason unknown yet but provision
  of seed by plaque or bacteria is likely (mainly
  filamentous bacteria)

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• Notes
• Calculus is higher in smokers.
• There is variation between different people in
  amount of calculus formed
• First stage of calculus formation (matrix
  deposition) occurs readily in both slow and rapid
  calculus formers
• The difference lies in the power to mineralize
  the matrix

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Possible factors effecting calculus formation

• Differences in plaque
• a) composition
• - increase Ca P more mineralization
• - decrease methyl pentose hexosamine
• b) increased rate of plaque formation in
  heavy calculus formers
  - therefore, the
  early stages, rather than the mineralization ,
  differed in the two groups

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• Differences in saliva composition
• increase protein, Ca phosphate calculus
• increase activities of acid phosphatase,
  pyrophosphatase, esterase more calculus
• increase urea more calculus
• increase lysozyme activity less calculus
• presence of low molecular weight protein adsorbed
  to apatite might act as seed calculus

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• The acidic protein of saliva said to prevent Ca
  ppt is either deficient or more rapidly broken
  down by bacteria calculus
• High viscosity of saliva less calculus
• Smoking leads to increased formation

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• Periodontal Disease
• Two most frequently occurring forms

2- Periodontitis
1- Gengivitis

• Limited to the gingival or soft tissues,
• surrounding the teeth
• Results in bleeding of gums, and
• possibly change in color, shape, size,
• surface texture and consistency
• Reversible on restoration of hygiene,
• does not result in destruction of
• tissues supporting the teeth

• Extension of the inflammatory process
• from the gingival to the supporting
• periodontal tissue destruction of
• these tissues
• Can be controlled but not reversed
• Chronic peridontitis result in loss of
• bone supporting the teeth mobility
• tooth loss

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The effect of plaque on the gingivae

• It was first thought that calculus caused
  gingivitis
• Volunteers not brushing for days developed
  gingivitis without calculus formation
• Conclusion Old plaque (gt 48 hours) periodontal
  disease, but calculus help by providing
  mechanical irritation

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The nature of toxins in plaque causing
Gingivitis

• Plaque contains substances which diffuse into the
  gingival tissues and irritate them ex.
• Proteolytic enzymes from bacteria release of
  a.a amines ammonia, H2S and
  mercaptans (all potential irritants)

broken
down
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• Plaque antigens such as bacterial endotoxins,
  enter the gingival and induce antibodies in the
  local lymph tissues.
• The interaction between antibodies antigens is
  beneficial, but it activates complement which in
  turn causes the release of substances contracting
  the smooth muscles of arterioles and increasing
  vascular permeability (cytokines edema)

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• This is part of the inflammatory response
  destruction of bone and periodontal fibers