This makes the rates of reaction very sensitive to ions and molecules in the solution that may absorb at the active growth sites and, while not significantly incorporating into the precipitated crystal phases, markedly influences the rates of mineralization and demineralization. Physical-chemical studies have shown that the mineralization of all the calcium phosphate phases is controlled by reactions at the surface rather than by diffusion of lattice ions through the contacting liquid phase. The variable pH conditions in plaque, expressed in terms of free ionic concentrations, will markedly alter the supersaturations with respect to typical calcium phosphate precursor phases such as dicalcium phosphate dihydrate (DCPD) and octacalcium phosphate (OCP).
Although salivary proteins are effective inhibitors of the mineralization reactions that take place in dental plaque, once adsorbed, their conformation may change to present surfaces that catalyze the nucleation of mineral phases.
A knowledge of the kinetics of growth of both individual calcium phosphate phases and their mixtures is important for elucidating the mechanism of calculus formation. The overall process, therefore, may involve the formation of metastable intermediates which may subsequently transform into the more stable hard deposits observed in vivo.
#DOG DENTAL CALCULUS UPDATE#
The guidelines are an update of the 2013 AAHA Dental Care Guidelines for Dogs and Cats. Although formation is determined by thermodynamic driving forces, kinetic factors are also important determinants for the precipitation of specific calcium phosphate phases. The 2019 AAHA Dental Care Guidelines for Dogs and Cats outline a comprehensive approach to support companion animal practices in improving the oral health and often, the quality of lif e of their canine and feline patients. The formation, development, and dissolution of hard deposits such as calculus are complex processes that involve numerous calcium phosphate phases as well as the interaction of these ions with organic molecules.
0 kommentar(er)
