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

Abstract

The influence of fluoride, carbonate, and fluoride in combination with carbonate on the in vitro remineralization of bovine enamel was investigated with the use of a sandwich technique. After demineralization, enamel slices were subjected for 610 h to remineralizing solutions with 0.03 or 1.0 ppm fluoride. At each fluoride level, either 0, 1, 10, 20, or 25 mmol/L carbonate was tested. After 0, 22, 62, 126, 192, 329, and 610 h of remineralization, contact microradiographs were made by Cu K alpha-radiation. At 0.03 ppm fluoride, carbonate had an inhibiting influence on remineralization. At 1.0 ppm fluoride, the inhibiting influence of carbonate changed into a stimulation of remineralizatization at 20 and 25 mmol/L carbonate. At 0, 1, and 10 mmol/L carbonate, fluoride had an inhibiting influence on remineralization. The differences in remineralization between the groups were explained by events concerning crystal growth, i.e., different types of minerals might have precipitated with differences in precipitation rates, and retardation of a precipitation step might have occurred under the various remineralization conditions. There was a mutual influence of fluoride and carbonate on the remineralization process. We conclude that the composition of the remineralizing solution with respect to fluoride and carbonate concentrations is important for the remineralization process.

In vitro fluoride uptake by bovine enamel from aesthetic restorative materials

“…We, however, chose bovine enamel to have a relatively large group of samples all from one jaw and reassure the baseline of fluoride content. Bovine teeth provide large, flat test surfaces with low fluoride content and comparable anatomy and calcification 15 . In contrast, human teeth provide small surfaces with differences in fluoride content among different groups of teeth.…”

The Effect of Fluoride On Apatite Structure and Growth

“…If supersaturated conditions become high enough to surpass the presumed activation energy barrier for nucleation of OHAp, precipitation of acidic calcium phosphates is inevitable. The presence of fluoride at high concentrations bypasses the participation of acidic precursors in favor of direct precipitation of fluoridated apatite crystals, even in physiological media (Lammers et al, 1991). This well-documented effect of fluoride as an accelerator of apatite formation is attributed to the fact that the thermodynamic solubility of apatite crystals decreases with incorporation of fluoride in the OH-lattice position (Moreno et al 1974), thereby increasing the driving force for precipitation of fluoridated apatite crystals.…”

Influences of bicarbonate on processes of enamel subsurface remineralization and demineralization: assessment using micro-Raman spectroscopy and transverse microradiography

“…Subsurface enamel lesions are formed when, over long periods of time, the rate of dissolution of minerals exceeds that of remineralization, such as under acidic conditions. Moreover, these subsurface enamel lesions can be repaired in the presence of calcium, phosphate, and fluoride ions present in saliva . Saliva is an important source of calcium and phosphate and also contains several buffering systems, including bicarbonate, phosphate, and peptides .…”

“…Lammers et al . reported that carbonate delays remineralization. This warrants further study on the influence of bicarbonate in saliva and of oral‐care products on enamel remineralization, as well as the anti‐demineralization effects of carbonate incorporated into enamel subsurface lesions.…”