The use of sodium trimetaphosphate as a biomimetic analog of matrix phosphoproteins for remineralization of artificial caries-like dentin

Abstract

Objectives-This study examined the use of sodium trimetaphosphate (STMP) as a biomimetic analog of matrix phosphoproteins for remineralization of artificial carious-affected dentin.Methods-Artificial carious lesions with lesion depths of 300±30 µm were created by pHcycling. 2.5% hydrolyzed STMP was applied to the artificial carious lesions to phosphorylate the partially-demineralized collagen matrix. Half of the STMP-treated specimens were bonded with One-Step. The adhesive and non-adhesive infiltrated specimens were remineralized in a Portland cement-simulated body fluid system containing polyacrylic acid (PAA) to stabilize amorphous calcium phosphate as nanoprecursors. Micro-computed tomography (micro-CT) and transmission electron microscopy (TEM) were used to evaluate the results of remineralization after a 4-month period.Results-In absence of PAA and STMP as biomimetic analogs (control groups), there was no remineralization irrespective of whether the lesions were infiltrated with adhesive. For the STMPtreated experimental groups immersed in PAA-containing simulated body fluid, specimens without adhesive infiltration were more heavily remineralized than those infiltrated with adhesive. Statistical analysis of the 4-month micro-CT data revealed significant differences in the lesion Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. NIH Public AccessAuthor Manuscript Dent Mater. Author manuscript; available in PMC 2012 May 1. NIH-PA Author ManuscriptNIH-PA Author Manuscript NIH-PA Author Manuscript depth, relative mineral content along the lesion surface and changes in ΔZ between the nonadhesive and adhesive experimental groups (p<0.05 for all the three parameters). TEM examination indicated that collagen degradation occurred in both the non-adhesive and adhesive control and experimental groups after 4 months of remineralization.Significance-Biomimetic remineralization using STMP is a promising method to remineralize artificial carious lesions particularly in areas devoid of seed crystallites. Future studies should consider the incorporation of MMP-inhibitors within the partially-demineralized collagen matrix to prevent collagen degradation during remineralization.

Dentine bonding agents comprising calcium-silicates to support proactive dental care: Origins, development and future

“…The infiltration of hydrophilic resin monomers into demineralized collagen matrix, to produce a hybrid layer (HL) that couples adhesives/ resin composites to the underlying mineralized dentine, provides ample opportunity for nano-leakage to occur beneath the restoration: oral fluids penetrate any poorly infiltrated area and serve as functional medium for the functioning of host-derived, collagen degrading matrix metalloproteinases (MMPs) 3) . While each experimental strategy that attempted to overcome these problems has its own benefits and reciprocal limitations 4) , progressive water replacement by hydroxyapatite generated during dentine remineralization may be a suitable strategy for extending the service life of resin-based dentine bonding procedures and its actualization has been a source of conjecture until now 5) . In this case, nano-leakage might only be a temporary phenomenon that could be solved by new hard-tissue formation 6) .…”

“…As remineralization proceeds, free and loosely bound water becomes less readily available to MMPs to initiate autolytic phenomena. Moreover, catalytic and allosteric domains of these enzymes may be fossilized and inactivated by the deposition of hydroxyapatite crystallites between polymer matrices and exposed collagen fibrils 5) . It has been suggested that molecular immobilization of the functional activity of collagenolytic enzymes could be accomplished in dental restorations with a guided tissue approach 7) .…”

Evaluation of Different Fluoride Concentrations Supplemented with Trimetaphosphate on Enamel De- and Remineralization in vitro

“…If TMP thereby replaced dissolved phosphate groups, the stronger adsorbing TMP groups would protect the surface against dissolution during a subsequent caries attack [McGaughey and Stowell, 1977]. Recently, a renewed interest in TMP has been shown for its role as a biomimetic analog of matrix phosphoproteins in the enhancement of carious dentine remineralization [Liu et al, 2011].…”

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].…”