Etiology of Periodontal Diseases - II- Role of Calculus and Local Factors

7/27/2019 Etiology of Periodontal Diseases - II- Role of Calculus and Local Factors

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Dental Plaque is the

primary etiologic

(initiating) factor ofperiodontal

inflammation


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Factors that facilitates and favor plaque

retention and accumulation are LOCAL

PREDISPOSING FACTORS

Systemic conditions that alter the host

response (i.e. make a person more susceptible

to disease) are SYSTEMIC FACTORS. These willbe covered next lecture


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Calculus

Malocclusion

Faulty restorationsOrthodontic therapy

Self-inflected injuries

Radiation therapy


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A. Inorganic Components (7090 %):

Calcium phosphate (76 %)Calcium carbonate (3 %)

Magnesium phosphate and other metals


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Inorganic component of calculus is madeof crystals with different chemical

composition as follows:

Hydroxyapatite 58 %

Magnesium Whitlockite 21 % (more in

posterior regions)

Octacalcium phosphate 12 %

Brushite 9 % (more in mandibular anterior

regions)


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B. Organic Components (10

30 %):

Carbohydrates (29%)

Proteins (6

8 %) Lipids (< 1%) such as fatty acids, neutral fats,

cholesterol, and phospholipids

Host cells and microorganisms


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Same as subgingival calculus with some

differences:

Magnesium Whitlockite Brushite and Octacalcium phosphate

calcium to phosphate ratio

No salivary proteins (because its

minerals are derived from the gingival

fluid)


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Four modes of attachment havebeen described:

1. Attachment by means of an

organic pellicle

2. Mechanical locking intosurface irregularities such

as resorption lacunae


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Four modes of attachment have been

described:

3. Close adaptation of calculusundersurface to cementum surfaces

4. Penetration of calculus bacteria intocementum


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Plaque is hardened by precipitation of mineral

salts

It starts 1

14 days of plaque formation

It is mineralized 50% in 2 days and 60-90& in 12

days

Plaque concentrates calcium ions 2 -20 times

its level in saliva


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Heavy, moderate, slight and non-calculusformers due to:

salivary pH salivary Ca++ bacterial protein and lipid concentration

protein and urea in submandibular salivary

gland secretions

total salivary lipid levels

individual inhibitory factors


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Anti-calculus (anti-tarter) agents have been

incorporated into some dentifrices to reduce

the calculus formation

These toothpastes may be help in heavy

calculus formers

However, plaque control measures are the

cornerstone in reduction of calculus rate


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Local rise in saturation of Ca++& P++ leadsto their precipitation. This precipitation is

due to any of the following factors:

pH

Colloidal proteins in saliva bind Ca++& P++

hydrolysis of organic phosphate due to theaction of phosphatase enzyme from

desquamated epithelial cells and bacteria


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Epitactic concept or heterogenous

nucleation: Seeding agents (e.g.

intercellular matrix) induce small foci ofcalcification that enlarge and coalesce to

form calcified masses


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Covered in previous lecture


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Interfere with the oral hygiene

measures

They favor the multiplication of

disease-associated

microorganisms


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Margins of restorations are

better to be placed

supragingivally as

aesthetically as possible

Dental restorations should be

as smooth as possible whenthey are related to the gingiva


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Over-contoured crowns andrestorations accumulate and

retain more plaque than

under-contoured restorations

Integrity of proximal contacts

prevents food impaction thatdeteriorates the periodontal

healthplunger cusp


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Malocclusion interferes with

plaque control by the patient

Prominent roots are associatedwith gingival recession and less

adequate attached gingiva

Gingival health deteriorates inmouth-breathers


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The misuse of

toothbrushes may resultin gingival abrasion and

alteration of teeth

shape


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A. Localized tooth-relatedfactors that modify or

predispose to gingival

diseases/periodontitis:

Tooth anatomic factors:

Enamel Pearls

Cervical Enamel

Projections


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Localized tooth-relatedfactors that modify or

predispose to gingival

diseases/periodontitis:

Root fractures

Cervical root resorption

and cemental tears


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Etiology of Periodontal Diseases - II- Role of Calculus and Local Factors

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