Relationship between Mineral Distributions in Dentine Lesions and Subsequent Remineralization in vitro

Abstract

Though the mineral distribution of the dentine carious lesion varies largely from tooth to tooth and from patient to patient, there are two main distribution profiles that characterize natural carious lesions in dentine. These profiles include softened and subsurface lesion types. The mineral distribution relationship between the starting profile and the profile after remineralization is not known. In order to study the relational aspects, we have produced demineralized dentine samples in vitro with mineral profiles similar to those of typical natural carious lesions, and subsequently remineralized the samples in a remineralizing solution with various fluoride concentrations (0, 2 and 10 ppm F). The mineral distributions were obtained by using an improved microradiographic technique. In addition, the nature of deposited mineral was analyzed by diamond–coupled total internal reflectance spectroscopy. Definite relationship was observed between the original lesion mineral distribution and the mineral distributions following remineralization. The amount of mineral present in approximately the first 50 μm of the lesion influenced the overall mineral profile after remineralization, possibly through influencing ion transport. If the amount was high (> approximately 10 vol%), the deposited mineral was confined to the surface (0–50 μm). The original mineral at those depths acted like a nucleus of mineral regrowth when the amount of residual mineral was intermediate, and like a transport barrier when the surface layer was well mineralized. If a surface barrier was not present, mineral was deposited at deeper depths in the lesion. Fluoride effect on dentine remineralization was dependent on the original mineral content and its distribution in the lesion. Although a high concentration of fluoride was very effective in low–mineral lesions, it produced hyperremineralization on well–mineralized subsurface lesions so that it prevented effective remineralization especially in deeper lesions.

Remineralization of Advanced Root Dentin Lesions in vitro

“…Arends et al, 1990]. Also, Kawasaki et al [2000] showed an effect of fluoride on remineralization of shallow (!165 Ìm) dentinal lesions with various mineral distributions. With an in situ model Nyvad et al [1997] showed -in comparison with non-treatment -that daily plaque removal and application of 2% NaF could inhibit progression and even result in partial remineralization of dentinal lesions Intra-oral fluoride levels between 0.04 and 0.1 ppm may be found in saliva and plaque fluid when a fluoride toothpaste or rinse is being used [Duckworth and Morgan, 1991;Leverett et al, 1993].…”

Dentine Remineralisation by Simulated Saliva Formulations with Different Ca and P_i Contents

“…1, formulation C, 14 days; data not quantified). This would allow only partial remineralisation, as observed for carious dentine remineralisation, with high mineral concentration on the surface layer preventing mineral diffusion to the subsurface [Kawasaki et al, 2000]. Accelerating the in vitro remineralisation time and allowing complete remineralisation may be an initial goal when developing products intending to prevent or reduce erosion progression in dentine.…”

Different Protocols to Produce Artificial Dentine Carious Lesions in vitro and in situ: Hardness and Mineral Content Correlation

“…It is important to point out that the kind of lesion influences the behavior to further de-or remineralization, as the surface layer, porosity and lesion depth can play an important role in the mineral diffusion [ten Cate, 1994;Kawasaki et al, 2000;Preston et al, 2008;Bertassoni et al, 2010].…”