Remineralization of artificial dentinal caries lesions by biomimetically modified mineral trioxide aggregate

Abstract

Fluoride-releasing restorative materials are available for remineralization of enamel and root caries. However, dentin remineralization is more difficult than enamel remineralization due to the paucity of apatite seed crystallites along the lesion surface for heterogeneous crystal growth. Extracellular matrix proteins play critical roles in controlling apatite nucleation/growth in collagenous tissues. This study examined the remineralization efficacy of mineral trioxide aggregate (MTA) in phosphate-containing simulated body fluid (SBF) by incorporating polyacrylic acid and sodium tripolyphosphate as biomimetic analogs of matrix proteins for remineralizing caries-like dentin. Artificial caries-like dentin lesions incubated in SBF were remineralized over a 6-week period using MTA or MTA containing biomimetic analogs in the absence or presence of dentin adhesive application. Lesion depths and integrated mineral loss were monitored with micro-computed tomography. Ultrastructure of baseline and remineralized lesions were examined by transmission electron microscopy. Dentin remineralization was best achieved using MTA containing biomimetic analogs regardless of whether an adhesive was applied; dentinal tubules within the remineralized dentin were occluded by apatite. It is concluded that the MTA version employed in the study may be doped with biomimetic analogs for remineralization of unbonded and bonded artificial caries-like lesions in the presence of SBF.

Surface pre-conditioning with bioactive glass air-abrasion can enhance enamel white spot lesion remineralization

“…Polyacrylic acid (PAA) altered the hydroxycarbonate apatite (HCA) induced by BAG 45S5, with smaller structures deposited on the surfaces of enamel WSLs, remineralized using PAA-BAG slurry and assessed using Raman micro-spectroscopy and SEM [7]. The ( COOH) functional group of PAA may bind the calcium and phosphate ions to form nano-precursors small enough to penetrate the carious lesion more effectively [19,20].…”

Effect of Lesion Baseline Severity and Mineral Distribution on Remineralization and Progression of Human and Bovine Dentin Caries Lesions

“…However, comparatively few such studies were conducted on root caries lesions as researchers have generally focused on lesion creation under different conditions [Shellis, 2010;Moron et al, 2013] or the study of fluoride and/or potentially cariostatic agents on de-and remineralization of one particular lesion type in situ [Wefel et al, 1995[Wefel et al, , 2002 and in vitro [Xie et al, 2008;Qia et al, 2012]. Nonetheless, a series of mechanistic studies [Kawasaki et al, 2000;Smith et al, 2005;Preston et al, 2008] found that lesion baseline mineral distribution affects fluoride response under subsequent remineralization, that smaller lesions are more prone to remineralization and that, as shown for enamel [ten Cate and Duijsters, 1982], the mineral and fluoride content of the surface layer determines the rate of remineralization.…”

Adhesive Materials with Bioprotective/Biopromoting Functions

“…This strategy reproduced both intrafibrillar and interfibrillar minerals and recapitulated the dimension and order of the apatite crystallites that are found in natural dentin [70][71][72][73]. Using this biomimetic remineralization strategy, both hybrid layers created by etch-and-rinse adhesives [68,74,75] and moderately aggressive self-etch adhesives [65,74,76], as well as 250-to 300-μm-thick completely demineralized dentin lesions, can be remineralized [77][78][79]. This bottom-up remineralization strategy does not rely on seed crystallites, and may be considered as a potentially useful mechanism in extending the longevity of resin-dentin bonds [80] via restoring the dynamic mechanical properties of the denuded collagen within the hybrid layer to approximate those of mineralized dentin [81].…”