TY - JOUR
T1 - Selective demineralisation of dentine extrafibrillar minerals—A potential method to eliminate water-wet bonding in the etch-and-rinse technique
AU - Li, Bingqing
AU - Zhu, Xiaoming
AU - Ma, Lin
AU - Wang, Fangping
AU - Liu, Xiaoqiang
AU - Yang, Xu
AU - Zhou, Jianfeng
AU - Tan, Jianguo
AU - Pashley, David Henry
AU - Tay, Franklin Chi Meng
N1 - Funding Information:
This study was supported by the National Natural Science Foundation of China (No. 81200807 ), Beijing Natural Science Foundation (No. 7162204 ), and Science Foundation of Chinese Stomatological Association ( CSA-B2015-08 ). The authors are grateful to Jianguo Zhang (Centre for Biological Imaging, Institute of Biophysics, Chinese Academy of Science, Beijing, P.R. China) for his help on scanning electron microscopy and Huiling Li (State Key Laboratory of Nonlinear Mechanics, Institute of Mechanics, Chinese Academy of Sciences, Beijing, P.R. China) for his assistance in atomic force microscopy-based nanoindentation.
Publisher Copyright:
© 2016
PY - 2016/9/1
Y1 - 2016/9/1
N2 - Objective The present study tested the central hypothesis that selective demineralisation of dentine extrafibrillar minerals by lowering the phosphoric acid concentration improves the quality of the resin-dentine interface. Methods Dentine surfaces were etched with different concentrations of phosphoric acid (1, 5, 10, 20, 30 or 40 wt%). Scanning electron microscopy was used to observe the micromorphology of the etched dentine surfaces. Energy dispersive X-ray analysis was performed to determine the residual Ca-content of the demineralised dentine matrix. Atomic force microscopy-based nanoindentation was used to analyse the nanomechanical properties of the treated dentine surfaces. The influence of H3PO4 concentration on resin-dentine bond strength was evaluated by microtensile bond strength testing. One-way ANOVA was used to compare the residual Ca-content ratio, reduced elastic modulus (Er) of the treated dentine surfaces and microtensile bond strength among groups. Results Collagen fibrils appeared to be wider in diameter after etching with 5% and 10% H3PO4. The partially-demineralized collagen scaffold retained part of its rigidity to maintain an uncollapsed three-dimensional structure. Etching with 1% H3PO4 resulted in the highest residual Ca-content ratio and Er of demineralised dentine matrix, followed by 5% H3PO4. Those values were all significantly higher than values derived from the other groups. Etching with 30% H3PO4 resulted in the lowest Ca-content ratio and Er. Using 5% H3PO4 as etchant resulted in the highest resin-dentine bond strength. Conclusions Selective demineralisation of the dentine matrix may be achieved by lowering the H3PO4 concentration to 5 wt%, to achieve better bonding performance. Clinical relevance By retaining intrafibrillar minerals, more through air-drying of the partially demineralised collagen matrix may be accomplished without the need to worry about collapsing a mineral-free collagen matrix during air-drying. This may result in the elimination of water-wet bonding during the application of etch-and-rinse adhesives.
AB - Objective The present study tested the central hypothesis that selective demineralisation of dentine extrafibrillar minerals by lowering the phosphoric acid concentration improves the quality of the resin-dentine interface. Methods Dentine surfaces were etched with different concentrations of phosphoric acid (1, 5, 10, 20, 30 or 40 wt%). Scanning electron microscopy was used to observe the micromorphology of the etched dentine surfaces. Energy dispersive X-ray analysis was performed to determine the residual Ca-content of the demineralised dentine matrix. Atomic force microscopy-based nanoindentation was used to analyse the nanomechanical properties of the treated dentine surfaces. The influence of H3PO4 concentration on resin-dentine bond strength was evaluated by microtensile bond strength testing. One-way ANOVA was used to compare the residual Ca-content ratio, reduced elastic modulus (Er) of the treated dentine surfaces and microtensile bond strength among groups. Results Collagen fibrils appeared to be wider in diameter after etching with 5% and 10% H3PO4. The partially-demineralized collagen scaffold retained part of its rigidity to maintain an uncollapsed three-dimensional structure. Etching with 1% H3PO4 resulted in the highest residual Ca-content ratio and Er of demineralised dentine matrix, followed by 5% H3PO4. Those values were all significantly higher than values derived from the other groups. Etching with 30% H3PO4 resulted in the lowest Ca-content ratio and Er. Using 5% H3PO4 as etchant resulted in the highest resin-dentine bond strength. Conclusions Selective demineralisation of the dentine matrix may be achieved by lowering the H3PO4 concentration to 5 wt%, to achieve better bonding performance. Clinical relevance By retaining intrafibrillar minerals, more through air-drying of the partially demineralised collagen matrix may be accomplished without the need to worry about collapsing a mineral-free collagen matrix during air-drying. This may result in the elimination of water-wet bonding during the application of etch-and-rinse adhesives.
KW - Collagen matrix
KW - Etch-and-rinse
KW - Interfibrillar space
KW - Intrafibrillar mineral
KW - Selective demineralisation
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U2 - 10.1016/j.jdent.2016.07.008
DO - 10.1016/j.jdent.2016.07.008
M3 - Article
C2 - 27443240
AN - SCOPUS:84979276996
SN - 0300-5712
VL - 52
SP - 55
EP - 62
JO - Journal of Dentistry
JF - Journal of Dentistry
ER -