A microbiological study of dental calculus

Abstract

Deposits obtained from the in vitro calcificaqtion of vialble adn formalin killed microorganisms have been examined by Von Kossa staining and X‐ray diffraction analysis. 34 of the 35 species examined were isolated from, and represcented, the flora of human calculus. Twenty‐one of the viable and 23 of the formalin‐killed cultures gave positive Von Kossa smears but idebntical results for live and dead preparations were obtained in only 25 of the 35 organisms examined. In viable cultres only, teh proportion of calcified organisms increased with time suggesting that degenrative change is probably a prerequistie for cellular calcification. The X‐ray diffraction analysis shwed that in clacified viable cultures hydroxyapatitie was always found (22) and in the majority of cases (18) was the sole from of crystalline with octocalcium phosphate and/or brushite (10), gave a weaker pattern than that given by similar viable cultures. In 9 deposits octocalcium phosphate and brushite were the only form s of calcium phosphate detected adn 6 of these gave positive Von Koss smears. The formation in vitro of these two forms suggests that, as previously recorded for hydroxyapatiti, the plaque microbiota may play a part in theri in vivo formation.

An unusual presentation of dental calculus

“…Saliva is the source for mineralization of supragingival calculus. It has been shown that the level of calcium in calculus is 20% more than in the saliva In this case report, when the hard mass which is present supragingivally, when analyzed biochemically it was found out that there was the presence of higher concentrations of calcium and phosphates which correlates well with the studies of Schroeder[9] and Hidaka et al [10]…”

Effect of phosphoproteins on intracellular calcification of bacteria

“…Bacterial degeneration is a precondition for intracellular calcification [14,19,25,[29][30][31]. According to this theory, bacteria denatured by aging or by external factors cause intracellular calcification.…”

“…This may explain why recognizing intracellular calcification takes a long time in many in vitro experiments. In one such experiment, formalin‐treated bacteria were more susceptible to calcification than non‐treated bacteria [31], but the detailed mechanism by which formalin treatment induces calcification is unknown. Most in vitro experiments do not involve pre‐denaturation, in which young and old bacteria are mixed [19].…”

Analysis of Predisposing Factors for Rapid Dental Calculus Formation

“…All samples were sent to a laboratory (Laboral, Barcelona, Spain) for semi-quantitative polymerase chain reaction (PCR) analysis to determine the presence and proportion of: Eubacterium saburreum, Corynebacterium matruchotii, Veillonella parvula, Streptocoucus salivarius, Streptocoucus sanguis and Streptococus mutans. According to various studies, these microorganisms are the calcifying species that predominate in supragingival calculus [6,7,17].…”

“…A series of factors are related to calculus formation. Those of note include factors related to increases in bacterial plaque retention [3], biochemical factors such as the composition of saliva or crevicular fluid [4,5], factors associated with the microorganisms that compose bacterial plaque [6][7][8], and factors related to diet [9].…”