2. Calculus consists of mineralized bacterial plaque that
forms on the surfaces of natural teeth and dental
prostheses.
Calculus is classified as supragingival or subgingival,
according to its relation to the gingival margin.
3. Supragingival Calculus
Supragingival calculus is located coronal to the
gingival margin and therefore is visible in the oral
cavity.
It is usually white or whitish in color, hard with clay-
like consistency, and easily detached from the tooth
surface.
The color is influenced by contact with such
substances as tobacco and food pigments.
It may localize on a single tooth or group of teeth, or
it mat be generalized throughout the mouth.
4. The two most common surfaces for supragingival
calculus to develop are the buccal surfaces of
maxillary molars and the lingual surfaces of the
mandibular anterior teeth.
Saliva from the parotid gland flows over the facial
surfaces of upper molars through Stenson’s duct.
The orifices of Wharton’s duct and Bartholin’s duct
empty onto the lingual surfaces of the lower incisors
from the submaxillary and sublingual glands,
respectively.
In extreme cases, calculus may form a bridge like
structure over the interdental papilla of adjacent
teeth or cover the occlusal surface of teeth without
functional antagonists.
7. Subgingival Calculus
Subgingival calculus is located below the crest of the
marginal gingiva and therefore is not visible on
routine clinical examination.
The location and extent of subgingival calculus may
be evaluated by careful tactile perception with a
delicate dental instrument such as an explorer.
Subgingival calculus is typically hard and dense and
frequently appears dark brown or greenish black
while being firmly attached to the tooth surface.
When the gingival tissues recede, subgingival
calculus becomes exposed and is therefore
reclassified as supragingival.
11. Composition
Inorganic Content:
Supragingival calculus consists of inorganic (70%-
90%) and organic components.
The inorganic portion consists of 75.9%calcium
phosphate, 3.2% calcium carbonate, and traces of
magnesium phosphate and other metals.
The percentage of inorganic constituents in calculus
is similar to that in other calcified tissues of the
body.
The principal inorganic components are calcium 39%,
phosphorus 19%, carbon dioxide 1.9%, magnesium
0.8%, and trace amounts of Na, Zn, Strontium, Br,
Cu, Mn, Tungsten, Au, Al, Si, Fe, and F.
12. At least two-thirds of the inorganic component is
crystalline in structure. The four main crystal forms
are as follows-
1. Hydroxyapatite (approx 58%).
2. Magnesium whitlockite (approx 21%).
3. Octacalcium phosphate (approx 12%).
4. Brushite (approx 9%).
Generally, two or more crystal forms are typically
found in a sample of calculus.
Hydroxyapatite and Octacalcium phosphate are
detected most frequently and constitute the bulk of
the specimen; Brushite is more common in the
mandibular anterior region and Magnesium
whitlockite in the posterior areas.
13. Organic Content:
The organic component of calculus consists of a
mixture of protein-polysaccharide complexes,
desquamated epithelial cells, leukocytes, and various
types of microorganisms.
Between 1.9% to 9.1% of the organic component is
carbohydrate.
Salivary proteins account for 5.9% to 8.2% of the
organic component of calculus and include most
amino acids.
Lipids account for 0.2% of the organic content.
14. The composition of subgingival calculus is similar to
that of supragingival calculus, with some differences.
Subgingival calculus has the same hydroxyapatite
content, more magnesium whitlockite, and less
brushite and octacalcium phosphate than
supragingival calculus.
The ratio of calcium to phosphate is higher
subgingivally, and the sodium content increases with
the depth of periodontal pockets.
Salivary proteins present in supragingival calculus
are not found subgingivally.
15. Attachment to the Tooth Surface
Differences in the manner in which calculus is
attached to the tooth surface affect the relative
ease or difficulty encountered in its removal.
The following four modes of attachment have been
described-
1. Attachment by means of an organic pellicle on
enamel.
2. Mechanical locking into surface irregularities,
such as resorption lacunae.
16. 3. Close adaptation of calculus undersurface
depressions to the gently sloping mounds of
the unaltered cementum surface.
4. Penetration of calculus bacteria into
cementum.
Not all investigators acknowledge the fourth mode
of attachment.
Calculus embedded deep in the cementum may
appear morphologically similar to cementum and
thus has been termed calculocementum.
21. Subgingival calculus (C) embedded beneath the
cementum surface (arrows) and penetrating to the
dentin (D), making removal difficult.
22. Formation
Calculus is dental plaque that has undergone
mineralization.
The soft plaque is hardened by the precipitation of
mineral salts, which usually starts between the first
and fourteenth days of plaque formation.
Calcification has been reported to occur as soon as 4 to
8 hours. Calcifying plaques may become 50%
mineralized in 2 days and 60% to 90% mineralized in
12 days.
All plaque does not necessarily undergo mineralization.
Plaque that does not develop into calculus reaches a
plateau of maximum mineral content within 2 days.
23. Saliva is the source of mineralization for
supragingival calculus, whereas the GCF furnishes
the minerals for subgingival calculus.
Plaque has the ability to concentrate calcium at 2 to
20 times its level in saliva.
Calcification entails the binding of calcium ions to the
carbohydrate-protein complexes of the organic
matrix and the precipitation of crystalline calcium
phosphate salts.
Calcification begins along the inner surface of the
supragingival plaque and in the attached component
of subgingival plaque adjacent to the tooth.
24. Separate foci of calcification increase in size and
coalesce to form solid masses of calculus.
As calcification progresses, the number of
filamentous bacteria increases, and foci of
calcification change from basophilic to eosiniphilic.
Calculus is formed in layers, which are often
separated by a thin cuticle that becomes embedded
in the calculus as calcification progresses.
Persons may be classified as heavy, moderate, or
slight calculus formers or as non-calculus formers.
25. Calculus formation continues until it reaches a
maximum, after which it may be reduced in amount.
The decline from maximal calculus accumulation,
referred to as reversal phenomenon, may be
explained by the vulnerability of bulky calculus to
mechanical wear from food and from the cheeks,
lips, and tongue.
Anticalculus (antitartar) dentifrices claim to reduce
the quantity and quality of calculus formed, making
it easier for removal by the clinician.
27. Theories on Mineralization of Calculus:
1. Mineral precipitation results from a local rise in the
degree of saturation of calcium and phosphate
ions, which may occur through the following
mechanisms-
a) An increase in the pH of saliva.
b) Colloidal proteins in saliva binding calcium and
phosphate ions to maintain a super-saturated
solution.
c) Phosphatase precipitating calcium phosphate
by hydrolyzing organic phosphates.
28. 2. Seeding agents induce small foci of calcification
that enlarge and coalesce to form a calcified mass.
This concept has been referred to as the
epitactic concept, or heterogenous
nucleation.
The seeding agents in calculus formation are not
known, but it is suspected that the intercellular
matrix of plaque playa an important role.
29. Role of Microorganisms in Mineralization of
Calculus:
Mineralization of plaque starts extracellularly around
both gram +ve and gram –ve organisms; it may also
start intracellularly.
Calculus formation spreads until the matrix and
bacteria are calcified.
Bacterial plaque may actively participate in the
mineralization of calculus by forming phosphatases,
which changes the pH of the plaque and induces
mineralization, but the prevalent opinion is that
these bacteria are only passively involved.
31. Iatrogenic Factors
Inadequate dental procedures that contribute to
the deterioration of the periodontal tissues are
referred to as iatrogenic factors.
Characteristics of dental restorations and
removable partial dentures that are important to
the maintenance of periodontal health include-
1. Location of gingival margin for the restoration.
2. Space between the margin of the restoration
and the unprepared tooth.
32. 3. Contour of restorations.
4. Occlusion.
5. Materials used in the restoration.
6. Restorative procedure itself.
7. Design of the removable partial denture.
33. Radiograph of amalgam overhang contributing to
plaque retention (left) and radiograph after excess
amalgam has been removed (right)…
34. Polished gold alloy crown demonstrates surface
scratches (left) and gold alloy crown that has been in
the mouth for several years having scratches filled
with deposits (right)…
35. After cementation, luting material prevents
approximation of the crown margin and the finishing
line, leaving part of the prepared tooth uncovered..
36. Craters have formed after dissolution and
disintegration of the luting material…
37. Inflamed marginal and papillary gingiva adjacent to
over-contoured porcelain-fused-to-metal crown on the
maxillary left central incisor (left) and radiograph of the
same (right)…
39. Malocclusion
Malocclusion may make plaque control difficult.
Certain issues are:
• Roots of teeth that are prominent in the
arch.
• Failure to replace missing posterior teeth.
• Tongue thrusting.
• Mouth breathing.
• Restorations that do not conform to the
occlusal pattern of the mouth.
40. Lower incisor showing prominent root with gingival
recession and lacking attached gingiva…
41. Same patient in previous photo after placement of a
soft tissue graft to gain attached gingiva and treat
gingival recession…
42. Anterior open bite with flared incisors, as observed in
association with a habit of tongue thrusting…
44. Periodontal Complications Associated with
Orthodontic Therapy
Orthodontic therapy may affect the periodontium by
favoring plaque retention, by directly injuring the
gingiva as a result of overextended bands, and by
creating excessive forces, unfavorable forces, or both
on the tooth and supporting structures.
• Plaque Retention and Composition.
• Gingival Trauma and Alveolar Bone Height.
• Tissue Response to Orthodontic Forces.
49. Palatal flap reflected to reveal bony dehiscence on the
maxillary lateral incisor in previous photo…
50. Extraction of Impacted Third Molars
Extraction of impacted third molars often results in
the creation of vertical defects distal to second
molars.
Other factors include-
• Presence of visible plaque.
• Bleeding on probing.
• Root resorption in the contact area between
2nd and 3rd molars.
• Presence of a pathologically widened follicle.
• Inclination of the 3rd molar.
• Proximity of the 3rd molar to 2nd molar.
52. Habits and Self-Inflicted Injuries
Mechanical forms of trauma can result from-
• Improper use of a toothbrush.
• Wedging of toothpicks between teeth.
• Application of fingernail pressure against
gingiva.
• Other causes (Eg: burns from pizzas etc).
Sources of chemical irritation include-
• Topical application of caustic medications
(aspirin, cocaine etc).
• Allergic reactions to tooth paste and chewing
gum.
• Use of chewing tobacco or concentrated
mouth rinses.
53. Gingival recession on a maxillary canine caused by
self-inflicted trauma from the patient’s fingernail…
55. Probing depth of 8mm with 10mm of clinical attachment
loss on lingual surface of lower central incisor adjacent
to oral jewelry in pierced tongue...
56. Overzealous use of a toothbrush may denude the
gingival epithelial surface and expose the underlying
connective tissue as a painful ulcer…
57.
58.
59. Tobacco Use
Smokers have greater attachment loss and bone
loss, an increased number of deep pockets, and an
increased amount of calculus formation.
Smokers are 2.6 to 6 times more likely to develop
periodontal disease than non-smokers.
Two possible explanations for smokers
experiencing more prevalent and severe
periodontal diseases are-
1. They harbor more pathogenic subgingival
microflora.
2. Their flora might be more virulent.
60. Smokers also exhibit reduced numbers of helper T
lymphocytes, which are important to stimulate B-cell
function for antibody production.
In summary, smoking has a negative effect on
periodontal therapy. However, periodontal therapy
does improve the periodontal condition of both
smokers and non-smokers when compared with their
pretreatment status.
Once the patients stop smoking, additional adverse
effects attributed to smoking may be minimized.
However, previous damage is not reversed.
Both non-smokers and former smokers respond
more favorably to periodontal therapy than smokers.
61.
62. Radiation Therapy
Radiation therapy has cytotoxic effects on both
normal cells and malignant cells.
Adverse effects of head and neck radiotherapy
include dermatitis and mucositis of the irradiated
area as well as muscle fibrosis and trismus.
Saliva production is permanently impaired when
salivary glands located within the portal of radiation
receive 6000cGy or more.
Xerostomia results in greater plaque accumulation
and a reduced buffering capacity from the remaining
saliva.
63. Periodontal attachment loss and tooth loss are
greater in cancer patients treated with high dose
radiation.
Irradiated patients should receive prophylactic
antibiotic coverage before receiving appropriate non
surgical periodontal therapy after the patient’s initial
recovery from radiation therapy.
The risk of osteoradionecrosis must be evaluated
before extracting a tooth or performing periodontal
surgery in an irradiated site.
Other required precautions must also be taken.
