It has the same hydroxyapatite content, more magnesium whitlockile, and less brushite and octac:ilcium phosphate.1 -m The ratio of calcium to phosphate is higher suhgiiigivully. I he composition of subgingival calculus is similar to that of supragingival calculus, with some differences. Lipids account tor 0,2% of the organic content in the form of neutral fats, free tatty acids, cholesterol, cholesterol esters. Salivary proteins account tor 5.9% to 8.2% ot the organic component of calculus and include most ammo acids. The organic component of calculus consists ot a mixture of protein-polysaccharide complexes, desquamated epithelial cells, leukocytes, and various types ot mic roorganisms.Between 1.9% and 9.1% ot the organic component is carbohydrate, which consists of galactose, glucose, rhamnose, mannose, glucuronic acid, galactosamine, and sometimes arabinose, galacturonic acid, and glucosamine.11, KM ,VS All these organic components are present in salivary glycoprotein with the exception of arabinose and rhamnose. I he incidence of the four crystal forms varies with the age of the deposit " Brushite is more common in the mandibular «interior region and magnesium whit-lot kite in the posterior areas. I Ivdroxyapatite and octa-calcium phosphate are detected most frequently (i.e., in 97% to 100% «if till supragingival calculus) and consti-tute the hulk of the specimen. (¡enerally, two or more crystal forms are typically found in a sample of calculus. I Ivdroxyapatite, approximately 58% Magnesium whitlockite, approximately 21'-Octacalcium phosphate, approximately 12% Brushite. 11-3 Dark pigmented deposits of subgingival calculus are shown on the distal root of an extracted lower molar.Ĭrystalline in structure.11" The four main crystal forms and their percentages are as follows: 11-4 A i I-year-old Caucasian male is shown with extensive Supragingival and subgingival calculus deposits throughout his dentitionįig. The inorganic portion consists of 75.9% calcium phosphate, Cail(>ntitl l)i\i'tt\, \įig. Supragingival calculus consists of inorganic (70% to 90%,lH) and organic components. However, the sensitivity level ot calculus detection by radiographs is low.' Ihe location of calculus does not indicate Ihe bottom ol the periodontal pocket because the most apical plaque is not sufficiently calcified to be visible on radiographs.Ĭomposition inorganic Content. ![]() Highly calcified interproximal calculus deposits are readily detectable as radioopaque projections that protrude into the interdental space d ig. Iloth supragingival calculus and subgingival calculus may be seen on radiographs (see Chapter \\). 89 adults in the United States between 19.1 This survey revealed that 91.8% of the subjects had detectable calculus and 55.1% had subgingival calculus. The location and extent ot subgingival calculus may be evaluated by careful tactile perception with a delicate dental instrument such as an explorer. Subgingival Lulitilus is located below tile crest l the marginal gingiva and therefore is not visible on routine clinical examination. In extreme cases, calculus may form a bridgelike struc ture over the interdental papilla of adjacent teeth or cover the occlusal surface of teeth without functional antagonists (Tig. 11-1 and 11 -2) and the lingual surfaces of the mandibular anterior teeth.M' Saliva from the parotid gland flows over the facial surfaces of upper molars vi.i Stensen's duct, whereas 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. The two most common locations for supragingival calculus to develop are the buccal surfaces of the maxillary molars (Tig. It may localize on a single tooth or group ot teeth, or it may be generalized throughout the mouth. The color is in-lluencetl by contact with such substances as tobacco and food pigments. Alter removal, it may rapidly recur, especially in the lingual area of the mandibular incisors. It is usually white or whitish yellow in color, hard with clay-like consistency, and easily detached from the tooth surface. Supragingiiiil alíenlas is located coronal to the gingival margin and therefore is visible in the oral cavity. Calculus is c lassified as supragingival or subgingival, according to its relation to the gingival margin. ![]() ('tihulus consists of mineralized bacterial plaque that forms on the surfaces of natural teeth and dental prostheses.
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