Calculus, oral

The addition of therapeutic or cosmetic agents to dentifrices has paralleled advances in knowledge about factors affecting the human dentition. Agents added to dentifrices can act directly on the host tooth stmcture or on specific oral accumulations, for example, the principal action of fluoride is on the tooth enamel. The primary action of an abrasive, however, is on an accumulated stained pellicle. Oral accumulations of interest to preventive dentistry are dental pellicles, dental plaque, dental calculus (tartar), microbial populations responsible for oral malodor, and oral debris (food residues, leukocytes, etc). Plaque is most important because of its potential to do harm. 

The present studies on calcium phosphate in bacteria are mostly of dental interest. Through the mineralization of the dental plaque dental calculus forms the soft, adherent and predominant coating which forms on the surface of teeth567. X-ray diffraction studies have shown the dental calculus to be composed of four principal minerals hydroxyapatite, octacalcium phosphate, brushite and whitelockite568. The mechanism by which mineralization of oral calculi is initiated is not fully understood567. Two types of mineralization centres can be distinguished which... 

Heisenberg soon outgrew the limited curriculum he studied Einstein s relativity on his own and taught himself calculus in order to tutor a college student for her final exams. For his final oral exams at the gymnasium, he solved the equations of projectile motion, taking into account air resistance. 

My own introduction to this field came during the course of my graduate studies when my mentor decided that I needed to learn the Jones calculus for treating optical phenomena. The department also possessed a Cary 60 spectrometer system, and in the time between my final oral exam and the beginning of my postdoctoral work I investigated the induction of circular dichroism in several metal complexes of acetylacetone by various chiral agents. Little did I know at the time that this particular work would subconsciously prepare me for the writing of one of the chapters in this book. 

Volpe AR, Kupczak LJ, Brant JH, et al. Antimicrobial control of bacterial plaque and calculus, and the effects of these agents on oral flora. / Dent Res 1969 48 832-841. 

Busscher HJ, White DJ, Kamminga-Rasker HJ, Van der Mei HC. A surface physicochemical rationale for calculus formation in the oral cavity. Cryst Growth 2004 261 87-92. 

Although many studies have attempted to relate oral calculus to the microflora which exists in plaque, such efforts appear to be self-defeating when it is realized that similar deposits occur on teeth of rats raised under germ-free conditions (Fitzgeredd and McDaniel, 1960). Thus it becomes apparent that, although such dahllite is surely related to organic processes, it is related to metabolic products of a vertebrate rather than microorganisms. 

In vitro experiments (McConnell et al., 1961) indicated that a substance which was crystallochemically comparable with oral calculus could be produced both from pooled human saliva and from a calcifiable synthetic solution to which a few mg 1 of carbonic anhydrase had been added. When a few mg 1" of sulfanilamide was added also, such a precipitate did not form, cleeirly indicating an interrelation between the formation of dahllite... 

Fisher, D.J. and McConnell, D., 1969. Aluminum-rich apatite. Science, 164 551—553. Fitzgerald, R.J. and McDaniel, E.G., 1960. Dental calculus in the germ-free rat. Arch. Oral Biol., 2 239—240. 

Schroeder, H.E. and Bambauer, H.U., 1966. Stages of calcium phosphate crystallization during calculus formation. Arch. Oral Biol., 11 1—14. 

Few papers that mention a possible association between calculus and caries have been reported since that time. In the most focused of these, Manji et al. [23] presented data from an oral health study involving 1131 Kenyans aged 15-65 years. By dividing the subjects into narrow age bands, these authors were able to demonstrate an inverse, but weak, association between calculus and caries. They concluded that the correlation was not strong enough to be of clinical significance. Of five further relevant studies [24-29], an inverse association between calculus and caries was reported in three [24,26,27], In each case, the correlations were weaker than those reported in section 1.2.1. 

Cahen et al. [25] found that the prevalence of both calculus and caries increased with age in an oral health study of 1993 young adults but did not report any correlation between the two parameters. In an earlier study [26] of 2000 children, the same research group estimated calculus to be fourth in the order of factors influencing caries prevalence after subject age, social group of father, and sex. The correlation between caries and calculus was negative, in agreement with expectation. 

De Paola et al. [28], in a study of the clinical profiles of 273 adults with and without root surface caries, found that those without root caries had less coronal caries and less calculus, as well as more teeth, less recession, less debris, less gingivitis and more abrasion, than subjects with root caries. They attributed most, if not all, of the differences to one underlying factor, oral hygiene. 

Recent calculus reviews [16, 30, 31] have not mentioned the possible relationship between caries and calculus. White [31] noted correlations between supra-gingival calculus and factors such as plaque and oral hygiene but not caries, though his review is focussed more on potential links to gingivitis. However, two papers in this time period do discuss the relationship. 

Of the many salivary and plaque factors potentially influencing calculus and caries, only oral calcium and inorganic phosphate levels appear to make a significant independent contribution, in the studies reviewed in section 1.5. The lack of discrimination between caries- or calculus-susceptible groups and corresponding non-susceptible groups in many studies of potentially relevant factors, is likely to be because subject numbers were too small. 

Huang S, Nakagaki H, Okumura H, Hayashizaki J, Negoro M, Adachi K, Tsuge S, Ando S, Robinson C, Pearce E, Huang A, Thi Than Ha N Fluoride profiles in dental calculus from Japanese, Chinese and British residents. Arch Oral Biol 1997 42 665-671. 

Jin Y, Yip H-K Supragingival calculus formation and control. Crit Rev Oral Biol Med 2002 13 426M41. 

Duckworth RM, Huntington E Evidence for putting the calculus caries inverse relationship to work. Comm Dent Oral Epidemiol 2005 33 349-356. 

Nancollas GH, Johnsson MAS Calculus formation and inhibition. Adv Dent Res 1994 8 307-311. White DJ Dental calculus recent insights into occurrence, formation, prevention, removal and oral health effects of supragingival and subgingival deposits. Eur J Oral Sci 1997 105 508-522. Pattanapom K, Navia JM The relationship of dental calculus to caries, gingivitis, and selected salivary factors in 11- to 13-year-old children in Chiang Mai, Thailand. J Periodontal 1998 69 955-961. 

Schroeder HE, Bambauer HU Stages of calcium phosphate crystallisation during calculus formation. Arch Oral Biol 1966 11 1-14. 

Hausmann E, Bisaz S, Russell RGG, Fleisch H The concentration of inorganic pyrophosphate in human saliva and dental calculus. Arch Oral Biol 1970 15 1389-1392. 

Poff AM, Pearce EIF, Larsen MJ, Cutress TW Human supragingival in vivo calculus formation in relation to saturation of saliva with respect to calcium phosphates. Arch Oral Biol 1997 42 93-99. 

Slomiany A, Slomiany BL, Mandel ID Lipid composition of human parotid saliva from light and heavy dental calculus-formers. Arch Oral Biol 1981 26 151-152. 

One of the main conclusions in Chapter 1 was that oral Ca and Pi were the only salivary/plaque constituents that appeared to correlate with caries and calculus in the expected direction, in studies of many specific factors in isolation. In this chapter, where the focus has been on relatively recent investigations of plaque composition as a whole, plaque Ca is rarely a discriminating factor for caries. Measures of plaque acidity (pH and lactate) are more often statistically significant. 

From a mechanistic viewpoint it is reasonable to anticipate an inverse clinical relationship between calculus and caries. Calculus formation is essentially a mineralisation process. The development of a caries lesion is the result of the net demineralisation of tooth enamel by plaque acid. These processes both involve crystalline calcium phosphate phases in contact with liquid, saliva and/or plaque fluid, containing their constituent ions. The oral environment also contains other salivary constituents and bacteria, which either inhibit or promote crystal growth or dissolution. 

An inverse relationship would mean that the absence of calculus could be a useful predictor of caries. Historically, however, any calculus-caries relationship has often been obscured by other factors. Firstly, the prevalence of both calculus and caries increases with increasing age [1,2] and, second, both conditions are expected to correlate positively with poor oral hygiene [3-5]. These trends could be the reason why Schroeder [1] found no consistent relationship between clinical observations of calculus and caries experience in the first major review of the topic. 

The alkaline environment also precipitates calcium and phosphate ions from the GCF, causing dental calculus. Dental calculus interferes with self-administered oral hygiene (Sect. 13.1.2) and asaccharolytic metabolism intensifies. When sulfur-containing amino acids (cysteine and methionine) are metabohzed, they release hydrogen sulfide along with the ammonia and short chain fatty acids. Hydrogen sulfide is a major contributor of oral malodor that often accompanies moderate to severe periodontal disease. 

Adhesive compositions for reducing, inhibiting and/or preventing calculus, tartar, plaque and/or microbes in the oral cavity comprise from about 15 to 70% of an alkyl vinyl ether maleic copolymer or terpolymer denture adhesive component, an effective amount of a quaternary ammoiuum antimicrobial agent selected from the group consisting of cetylpy ridinium chloride, domiphenbromide or mixtures thereof, and a non-aqueous vehicle. 

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