The Growth of Calcium Phosphates on Hydroxyapatite Crystals. The Effect of Fluoride and Phosphonate

Abstract

The nature of the calcium phosphate phase which precipitates on hydroxyapatite seed crystals can be controlled by varying the HAP seed concentration. At low seed concentrations, dicalcium phosphate dihydrate (DCPD) is formed while at high seed levels a more basic phase precipitates. It has been found that fluoride ion increases the percentage of basic phase that crystallizes while ethylidenediphosphonic acid encourages the formation of DCPD. This behavior is explained by the competition between the nucleation of DCPD and the crystal growth on sites already present on the HAP seeds.

Influence of Fluoride and pH on in vitro Remineralization of Bovine Enamel

“…These proposed pathways are in agreement with findings in the literature [Eanes and Meyer, 1978;Eanes, 1980]. At pH 5.5 precipitated DCPD is able to react with fluo ride in order to form (F)OHA [Chow and Brown, 1974], With increasing amounts of fluoride in the solutions, a de crease in the amount of DCPD as fraction of the precip itated phase was observed, while a more basic calcium phosphate phase precipitated [Barone and Nancollas, 1978b], Accordingly, in our experiments, at 0.3 ppm fluo ride the net amount of remineralization increased, as the formation of DCPD and (F)OHA from DCPD was stim ulated. At 1.0 ppm fluoride only the formation of (F)OHA was stimulated.…”

Fluoride Modulates the Inhibition of in Vitro Hydroxyapatite Crystal Growth by Small Dentin Proteoglycan: Relevance to Dental Calculus

“…Above 0.5 ppm, fluoride was reported to promote the precipitation of HAP on HAP seed crystals (Barone and Nancollas, 1978). However, at pH 7.4, with low concentrations of fluoride (0.15 ppm), there was a reported decrease in the rate of growth on HAP seeds in the initial stages, but an enhancement of mineralization observed in the presence of higher concentrations of fluoride (1-5 ppm) (Amjad and Nancollas, 1979).…”

“…Fluoride is known to enhance crystal growth (Barone and Nancollas, 1978;Varughese and Moreno, 1981). A wide variety of chemical inhibitors of crystal growth has been tested for their clinical efficacy; among these, pyrophosphate, ethane hydroxydiphosphonate, and zinc salts in the form of zinc citrate have been widely studied and reviewed extensively (Featherstone et al, 1989;Stookey et al, 1989).…”

Bis[2-(cyclopropyliminomethyl)-5-methoxyphenolato]zinc(II)

“…For applications of metal phosphates, see: Barone & Nancollas (1978); Dickinson et al (1996). For non-centrosymmetric phosphates with non-linear optical properties, see: Noor & Dam (1986); Aguilo & Wuensdregt (1985); Masse & Grenier (1971 has been used in dentistry (Barone & Nancollas, 1978) and Sr 5 (PO 4 ) 3 F (Dickinson et al, 1996) has been used as a laser crystal in laser technology.…”

“…For non-centrosymmetric phosphates with non-linear optical properties, see: Noor & Dam (1986); Aguilo & Wuensdregt (1985); Masse & Grenier (1971 has been used in dentistry (Barone & Nancollas, 1978) and Sr 5 (PO 4 ) 3 F (Dickinson et al, 1996) has been used as a laser crystal in laser technology. Especially, some non-centrosymmetric phosphates have been used as important crystals with nonlinear optical properties, such as KH 2 PO 4 (KDP) (Noor & Dam, 1986), NH 4 H 2 PO 4 (ADP) (Aguilo & Wuensdregt, 1985) and KTiOPO 4 (KTP) (Masse & Grenier, 1971 There are channels in the anionic substructure along [1 0 1] (Fig.…”