Dental Calculus and other Predisposing Factors

Dental Calculus and other Predisposing Factors

Calculus

Mineralized bacterial plaque that forms on tooth surface and dental prostheses

Divided into Supragingival and Subgingival Calculus in relation to gingival margin

3/17/2020 2Dr Saif Khan

Supragingival calculus

White or Whitish yellow in color

Hard with clay like consistency

Can be eaisly detached from

tooth surface

Color can be influenced by

contact with tobacco and food

pigment

Two most common locations are

buccal surface of maxillary molars

and lingual surface of mandibular

anterior teeth


Subgingival calculus

• Located below the crest of marginal gingiva

• Not visible on routine clinical examination

• Location and extent can be evaluated by careful tactile examination using explorer


Subgingival calculus

Typically hard and dense

Dark brown or greenish black in color

Firmly attached to tooth surface

Microscopic studies show that subgingival calculus

may extend nearly to base of periodontal pockets

but do not reach junctional epithelium


• Supragingival calculus and subgingival calculus

generally occur together, but one may be present

without other

• When gingival tissue recede, subgingival calculus

becomes supragingival

• Thus supragingival calculus can be composed of

both supragingival and previous subgingival

calculus


Both Supragingival

and Subgingival

calculus can be seen

on radiographs

However sensitivity of

calculus detection by

radigraphs is low


Composition

• Supragingival calculus consists of

Inorganic(70-90%) and Organic components

1. Inorganic components

– 75.9 %CaPO4, 3.1% CaCO3, Traces of

Mg3(PO4)2

• Principal inorganic components are

– Ca (39%), P (19%), CO2(3.1%), Mg (0.8 %),

Traces of Na, Zn, Sr, Br, Cu, Mn, Au, Al, Si, Fe, F,


• At least two-third of inorganic component is

crystalline in structure in 4 types

– Hydroxyapatite (58%)

– Magnesium Whitlockite (21%)

– Octacalcium Phosphate (12%)

– Brushite (9%)

3/17/2020 Dr Saif Khan 9

• Hydroxyapatite and Octacalcium phosphate are

detected most frequently (97 to100% of all

supragingival calculus)

• Brushite in mandibular anterior region

• Magnesium Whitlockite in posterior region

• The incidence of the four crystal varies with age of

deposit

• Dental calculus, salivary duct calculus and calcified

dental tissue are similar in inorganic composition


2.Organic component

• Consists of mixture of Protein- polysacchride

complexes, desquamated epithelial cells,

leukocytes and various types of

microorganisms

• Carbohydrate(1.9-9.1%) consists of galactose,

glucose, rhamnose, mannose, glucouronic acid,

galactosamine and sometimes arabinose,

galactouronic acid and glucosamine

– All these are present in salivary glycoprotein except

arabinose and rhamnose


• Salivary protein account for 5.9% to 8.2% of

the organic components of of calculus and include

most of the amino acids

• Lipids account of 0.2% of the organic

component in the form of neutral fats, free fatty

acids, cholesterol, cholesterol ester and

Phospholipids


ComparisionContents: Supra gingival calculus Sub gingival calculus

Hydroxyappatite:

Octa Calcium Ph :

Mg white:

brushite:

ratio of Ca/Ph:

sodium contents:

salivary proteins

Equal.

More.

Less.

More.

Low.

Increase with the

depth of PD pocket.

Yes

Equal

Less.

More

Less.

Higher.

No.


4 modes of attachment of calculus

• Organic Pellicle

• Mechanical locking into surface irregularities such as resorption lacunae

• Close adaptation of calculus undersurface depression to gently sloping mounds of unaltered cemental surface

• Penetration of calculus into cementum (Calculocementum)


Calculus formation

Calculus is the dental plaque that undergoes

mineralization.

Calcification starts 4-8 hrs after plaque

formation.

50 % become mineralized after 2 days


60-90 % becomes mineralised after 12 days

All plaque do not necessarily undergo calcification

Plaque that does not develop into calculus

reaches a plateau of maximal mineral content

within 2 days


Saliva is the source of mineralization for

Supragingival calculus whereas GCF furnishes

minerals for subgingival calculus

Plaque has the ability to concentrate calcium 2-

20 times its level in saliva

Phosphorous is more critical than Ca in plaque

mineralization


Calcification entails the binding of Ca ions to

carbohydrate protein complex of the organic

matrix and the precipitation of crystalline

calcium phosphate salts

Crystals form first in the intercellular matrix, then

on bacterial surface and finally within bacteria


Calcification begins along the inner surface of the

supragingival plaque and in the attached

component of subgingival plaque adjacent to

tooth

Separate foci of calcification increase in size and

coalesce to form solid masses of calculus


Calcification of the plaque is accompanied by alteration in bacterial content and staining qualities

– Filamentous bacteria increase in number

– Staining of plaque change from basophilic to

eosinophilic

– Reduction in PAS positive stain


– Sulfhydryl and amino groups are reduced

– Stain with toluidine blue which is intially orthochromatic becomes metachromatic and then disappears


Calculus is formed in layers, which is often

separated by thin cuticle that become

embedded in the calculus as calcification

process progresses


• The initiation of calcification and the rate of

calculus accumulation vary from person to

person, for different teeth, and at different

times in the same person

– Slight calculus former

– Moderate calculus former

– Heavy calculus former


• The average daily increment in calculus formers is from 0.10% to 0.15% of dry weight


Reversal phenomenon

Calculus formation continues until it reaches a

maximum after which it may be reduced in

amount

This decline from maximal calculus

accumulation is called reversal phenomenon

The time required to reach maximal level has

been 10 weeks and 6 months3/17/2020 Dr Saif Khan 25

Theories of calculus formation

The mechanism by which plaque becomes mineralized can beexplained by two theories

1. Mineral precipitation

Results from local rise in the degree of saturation of calcium and

phosphate ions which can occur through

• Increase in pH of saliva causes precipitation of CaPO4 by

lowering of precipitation constant

pH is elevated by loss of CO2 and formation of ammonia by dental plaque bacteria or by

protein degradation during stagnation

• Colloidal proteins in saliva bind Ca and Phosphate ions and

maintain supersaturated solution with respect to calcium

phosphate salts

with stagnation of saliva, colloids settle out and supersaturated solution is no longer

maintained leading to precipitation of calcium phosphate salts


• Phosphatases liberated from dental plaque,desquamated

epithelial cells, or bacteria precipitates calcium phosphate by

hydrolyzing organic phosphate in saliva, thus

increasing the concentration of free phosphate ions

• Esterase another enzymes present in cocci and filamentous

organism, leukocyte, macrophages and dequamated

epithelial cells of dental plaque

Esterase may initiate calcification by hydrolyzing fatty

ester into fatty acids

The fatty acids form soaps with Ca and Mg that are later

converted into less soluble calcium phosphate salts


2.Seeding agents

• Carbohydrate-protein complexes may initiate calcification by removing Ca from saliva(chelation) and binding with it to form nuclie that induce subsequent deposition of minerals

• Induce small foci of calcification that enlarge and coalesce to form calcified mass

• This concept is called epitactic concept or heterogenous nucleation


Role of microorganisms in mineralization of calculus

• Bacterionema and Veillonella species have the ability to form intracellular apatite crystals

• Bacterial plaque may actively participate in mineralization of calculus by forming phosphates which change pH of the plaque and induce mineralization


Etiologic significance

A positive correlation between presence of calculus and

the prevalance of gingivitis exists but this correlation is

not as great as between plaque and gingivitis

The non mineralised plaque on calculus surface is the

principal irritant, but underlying calcified portion may be

significant contributing factor

The incidence of calculus,gingivitis and periodontal disease

increases with age


Other predisposing factors

1.Iatrogenic factorsi. Location of gingival margin for the restoration

ii. Space b/w margin of restoration and unprepared tooth

iii. Contour of restoration

iv. Occlusion

v. Material used in the restoration

vi. Restorative procedure itself

vii. Design of the RPD


2.Malocclusion• Positive correlation between crowding and

periodontal disease

• Roots of teeth that are prominent in arch are associated with high frenal attachment and frequently exhibit reccession

• Tongue thrusting habit lateral pressure on anterior teeth resulting in spreading and tilting of anterior teeth leading to open bite

• Mouthbreathing may marginal and pappillary gingivitis in upper anterior region


3.Periodontal complication associated with orthodontic therapy

A. Plaque retention and composition

• Increase in P melaninogenica, P intermedia and A

odontolyticus and decrease in in proportion of facultative

microorganisms were detected in gingival sulcus after

placement of orthodontic bands

• Decrease in proportion of facultative microorganisms

were detected in gingival sulcus was seen after placement

of orthodontic bands


B. Gingival trauma and alveolar bone height

The mean alveolar bone loss per patient for

adolescent who went 2 years of orthodontic

care during 5 yr peroid range b/w 0.1 and

0.5mm


C. Tissue response to orthodontic forces

Excessive orthodontic forces also increase the risk of apical

root resorption

Surgical exposure of impacted teeth and orthodontic- assisted

eruption may compromise the periodontal attachment on

adjacent teeth

Dento-alveolar gingival fibers located within the marginal and

attached gingivae are streched when teeth are rotated during

orthodontic treatment3/17/2020 Dr Saif Khan 35

4.Extraction of impacted third molars

Various clinical studies have suggested that

extraction of impacted third molars results in

creation of vertical defect distal to second

molars


5.Habits and self-inflicted injuries

• Toothbrush trauma

• Chemical injury

• Trauma associated with oral jewelry


6. Tobacco use

• Smokers are 2.6 to 6 times more likely to

develop periodontal disease than non-smokers

• Smokers have more pathogenic subgingival

microflora with increased virulence

• Smokers have negative effect on periodontal therapy


7.Radiation therapy

– Oral mucositis

– Soft tissue ischaemia & fibrosis

– Irradiated bone is hypovascular and hypoxic

– Osteoradionecrosis

– xerostomia


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Dental Calculus and other Predisposing Factors