Please use this identifier to cite or link to this item: http://repositorio.unicamp.br/jspui/handle/REPOSIP/69395
Type: Artigo de periódico
Title: In vitro load-induced dentin collagen-stabilization against MMPs degradation
Author: Toledano, M
Aguilera, FS
Yamauti, M
Ruiz-Requena, ME
Osorio, R
Abstract: Introduction: Teeth are continuously subjected to stresses during mastication, swallowing and parafunctional habits, producing a significant reduction of the bonding efficacy in adhesive restorations. The purpose of this study was to evaluate the metalloproteinases (MMPs)-mediated dentin collagen degradation of hybrid layers created by using different demineralization processes, previous resin infiltration, and in vitro mechanical loading. Methods: Human dentin beams (0.75 x 0.75 x 5.0 mm) were subjected to different treatments: (1) untreated dentin; (2) demineralization by 37% phosphoric acid (PA) or by 0.5% M ethylenediaminetetraacetic acid (EDTA); (3) demineralization by PA, followed by application of Adper (TM) Single Bond (SB); (4) demineralization by EDTA, followed by application of SB. In half of the specimens, mechanical loadings (100,000 cycles, 2 Hz, 49 N) were applied to dentin beams. Specimens were stored in artificial saliva. C-terminal telopeptide (ICTP), determinations (which indicates the amount of collagen degradation) (radioimmunoassay) were performed after 24 h, 1 week and 4 weeks. Results: Load cycling decreased collagen degradation when dentin was untreated or PA-demineralized and EDTA-treated. ICTP values increased when both PA-demineralized and EDTA-treated and infiltrated with SB dentin beams were loaded, except in samples that were subjected to EDTA treatment and SB infiltration after 4 w of storage, which showed similar values of collagenolytic activity than the non loaded specimens. Load cycling preserved the initial (24 h) ICTP determination at any time point, in all groups of the study, except in PA-demineralized and SB infiltrated dentin which showed an increased of collagen degradation values, over time. This same trend was observed in all groups without loading. Interpretation: Mechanical loading enhances collagen's resistance to enzymatic degradation in natural and demineralized dentin. Mild acids (EDTA) lead to a lower volume of demineralized/unprotected collagen to be cleaved by MMPs. Load cycling produced an increase of collagen degradation when PA-demineralized dentin and EDTA-treated dentinwere infiltrated with resin, but EDTA-treated dentin showed a constant collagenolytic degradation, over time. (C) 2013 Elsevier Ltd. All rights reserved.
Subject: Dentin
Load cycling
Collagen degradation
Resin infiltration
Longevity
Restoration
Adhesion
Country: Holanda
Editor: Elsevier Science Bv
Rights: fechado
Identifier DOI: 10.1016/j.jmbbm.2013.06.002
Date Issue: 2013
Appears in Collections:Artigos e Materiais de Revistas Científicas - Unicamp

Files in This Item:
There are no files associated with this item.


Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.