Remineralization of Bovine Incisor Root Lesions in vitro: The Role of the Collagenous Matrix

Abstract

This study deals with the role of collagen in the remineralization of bovine incisor root lesions. The degradability of the collagenous matrix after in vitro remineralization was also investigated. The root surfaces were exposed to 0.1 M acetic acid, pH 4.0, to produce erosive lesions or to 0.1 M lactic acid, 0.2 mM methane hydroxy diphosphonate, pH 5.0, to produce subsurface lesions. After demineralization, the roots were subjected to remineralization, with or without prior treatment with a bacterial collagenase to remove accessible collagen. Remineralization was carried out in solutions with a Ca/P_i molar ratio of 1.67, and [Ca]·[P_i] concentration products of 0.6, 1.35 or 2.4 mM², with all solutions having an ionic strength of 0.15 M, and a pH of 7.0. After remineralization, the roots that were not treated with collagenase were incubated with the enzyme. The results indicate that remineralization of erosive lesions is surface-controlled and that of subsurface lesions diffusion-controlled. For both lesion types it was shown that the removal of collagen before remineralization did not affect the rate of mineral deposition in the root lesions. Nevertheless, remineralization in those lesions where accessible collagen had not been removed resulted in a significant reduction in the amount of degradable collagen. The observations of this study suggest that remineralization did not occur by nucleation of mineral on the organic matrix but rather by growth of residual crystals in the partially demineralized root tissue.

Effects of zinc fluoride on inhibiting dentin demineralization and collagen degradation <i>in vitro</i>: A comparison of various topical fluoride agents

“…With this barrier, the acid diffusing inward and the dentin mineral diffusing outward were retarded, thereby inhibiting further demineralization of Ca and phosphate ions from the lesion body 15) . However, Klont revealed that there was no influence on lesion remineralization in-vitro when removing demineralized collagen by enzyme 16) . Present authors hypothesized that inhibiting collagen degradation leads to anti-demineralization in dentin.…”

Fluorine analysis of human dentin surrounding resin composite after fluoride application by μ-PIGE/PIXE analysis

“…Because high concentration of fluorine was detected into hybrid layer, we guessed deposits of fluoroapatite in the collagen network of the hybrid layer; this remineralization of dentin occurs by precipitation onto residual crystals [25]. Thus, the hybrid layer might be reinforced by the remineralization process.…”

Adhesive Materials with Bioprotective/Biopromoting Functions

“…Apart from the functions mentioned above, fluoride ions penetrating into the dentin have been shown to enhance mineralization of the dentin [61][62][63]. This applies especially to the improved dissolution resistance initiated by epitaxial deposition of fluorapatite over remnant apatite crystallites in the hybrid layer [64]. In this conventional remineralization strategy, fluoride requires the presence of some apatite crystals in the partially demineralized dentin to initiate deposition of new mineral [65].…”