SAS 7: CALCULUS

calculus

usually occurs within 1-14 days

formed by precipitation of mineral salts into plaque

is nothing but, dental plaque that has undergone mineralization

covered with a layer of bacterial plaque, continues until it reaches maximum levels within 10 weeks and 6 months

calcification begins in individual foci on the plaque's inner surface, which gradually grow and form a solid mass of calculus.

reversal phenomenon

a decline in its formation due to mechanical wear from food and from the lips, cheeks and tongue

dental calculus

an adherent, calcified or calcifying mass that forms on the surfaces of teeth and dental appliances

covered on its external surface by vital, tightly adherent, nonmineralized plaque

2 types of calculus

supragingival calculus

subgingival calculus

supragingival calculus

aka: salivary calculus—because it forms from the saliva

white / yellow

mineralization via saliva

occurs near salivary duct openings

it is the tightly adherent calcified deposit

forms on the clinical crowns of the teeth above the free gingival margin—it is clinically visible

hard & clay-like

consistency of supragingival calculus

subgingival calculus

aka: serumal calculus—because it is believed to be formed the gingival exudates

mineralization via GCF

dark-brown / greenish-black

formed on the root surfaces below the free marginal gingiva

calculus can be detected visually (esp with air) or with an explorer

interproximal calculus deposits can be detected radiographically

2 forms of subgingival calculus

ring-like

ledge-like formations

the main crystal forms

brushite

hydroxyapatite

magnesium whitlockite

octacalcium phosphate

inorganic components

brushite

calcium

sodium

fluoride

carbonate

magnesium

phosphorus

crystal forms

hydroxyapatite

magnesium whitlockite

octacalcium phosphate

organic components

lipids

protein

leukocytes

polysaccharide complexes

desquamated epithelial cells

carbohydrate (glucose, galactose, rhamnose, mannose)

4 types of attachment of calculus to tooth surface

attachment by means of an organic pellicle

penetration of calculus bacteria into cementum

mechanical interlocking into surface irregularities such as resorption lacunae and caries

close adaption of calculus under surface depressions to the gently sloping mounds of the unaltered cementum surface

—calculus when embedded deeply in cementum may appear similar in morphology and thus has been termed as calculocementum

theories of calculus formation

inhibition theory

epitactic concept (heterogenous nucleation)

precipitation of minerals can occur from a local rise in the degree of saturation of calcium and phosphate ions

materia alba

soft white cheese-like unorganized accumulation of bacteria, salivary proteins, desquamated epithelial cells, and occasional food debris

easily displaced with water spray

iatrogenic factors

faults in the dental restorations and prosthesis

common causes of gingival inflammation & periodontal destruction

6 important characteristics of restorations from periodontal pov

occlusion

dental materials

margins of restorations

restorative procedures themselves

design of removable partial dentures

contours and overhanging dental restorations

biologic width

defined as the dimension of the soft tissue

is attached to the portion of the tooth coronal to the crest of the alveolar bone

commonly stated to be 2.04 mm, which represents the sum of epithelial and connective tissue measurements

plunger cusps

cusps that tend to forcibly wedge the food interproximally

extrinsic stains

do not contribute to gingival inflammation and are primarily an esthetic concern

orange

usually on anterior teeth, poor OH

brown

drinking dark-colored beverages, poor OH

dark brown & black

tobacco

yellow-brown

CHX and stannous fluoride

black

thin lines on cervical third

found in healthy mouths

consumption of iron

green & yellow

usually on anterior teeth

poor OH & chromogenic bacteria

bluish-green

occupational exposure of metallic dust

faulty restorations

open margins

rough surfaces

overhanging margins

open contacts can all create an environment conducive to plaque retention

over-contoured restorations are worse for gingival health than under-contoured restorations

malocclusion

crowding can contribute to plaque retentive areas

high frena-associated roots and teeth often experience gingival recession, while missing teeth may cause mesial drift or extrusion, leading to food impaction and plaque retention.

subgingival margins

even when not faulty they are associated with plaque accumulation, gingival inflammation, & deeper pockets

appliances

RPDs — result in increased mobility of abutment teeth & increased plaque accumulation

orthodontic therapy — can create excessive forces on the periodontium

—periodontal health must be established before initiating orthodontic therapy

oral jewelry — result in recession, pocket formation & bone loss

self-inflicted injury

aggressive horizontal brushing can cause tooth abrasion & gingival recession

improper use of toothpicks & fingernail biting can damage gingival tissues

pyrophosphates

this agent inhibits calculus formation

occlusal adjustment

contraindicated in the treatment of bruxism

tongue thrusting

it is the persistent, forceful wedging of the tongue against the teeth

examples of parafunctional habits

bruxism & clenching