Effect of Biomimetic Remineralization on the Dynamic Nanomechanical Properties of Dentin Hybrid Layers

• Published in: Journal of dental research Vol. 90; no. 9; pp. 1122 - 1128
• Main Authors: Ryou, H., Niu, L.-N., Dai, L., Pucci, C.R., Arola, D.D., Pashley, D.H., Tay, F.R.
• Format: Journal Article
• Language: English
• Published: Los Angeles, CA SAGE Publications 01-09-2011; International Association for Dental Research; SAGE PUBLICATIONS, INC
• Subjects: Aging; Apatite; Biological and medical sciences; Dental Bonding; Dental Etching; Dental Stress Analysis - methods; Dentin; Dentin - chemistry; Dentin Permeability; Dentin-Bonding Agents; Dentistry; Elastic Modulus; Head and neck surgery. Maxillofacial surgery. Dental surgery. Orthodontics; Humans; Materials Testing; Maxillofacial surgery. Dental surgery. Orthodontics; Mechanical properties; Medical sciences; Methacrylates; Nanotechnology; Remineralization; Research Reports; Statistics, Nonparametric; Surgery (general aspects). Transplantations, organ and tissue grafts. Graft diseases; Tooth Remineralization - methods; remineralization; hybrid layer; dynamic mechanical behavior; scanning probe microscopy; dentin bonding; biomimetics; Dentin; Human; Scanning probe microscopy; Mechanical properties; Adhesive bonding; Etching; Dynamic mechanical properties; Tooth; Nanotechnology; Remineralization
• ISSN: 0022-0345; 1544-0591
• DOI: 10.1177/0022034511414059

The mineral and organic phases of mineralized dentin contribute co-operatively to its strength and toughness. This study tested the null hypothesis that there is no difference in nano-dynamic mechanical behavior (complex modulus-E*; loss modulus-E′′; storage modulus-E′; in GPa) of dentin hybrid layers (baseline: E*, 3.86 ± 0.24; E′′, 0.23 ± 0.05; E′, 3.85 ± 0.24) created by an etch-and-rinse adhesive in the presence or absence of biomimetic remineralization after in vitro aging. Using scanning probe microscopy and nano-dynamic mechanical analysis, we demonstrated that biomimetic remineralization restored the nano-dynamic mechanical behavior of heavily remineralized, resin-sparse regions of dentin hybrid layers (E*, 19.73 ± 3.85; E′′, 8.75 ± 3.97; E′, 16.02 ± 2.58) to those of the mineralized dentin base (E*, 19.20 ± 2.42; E′′, 6.57 ± 1.96; E′, 17.39 ± 2.0) [p > 0.05]. Conversely, those resin-sparse, water-rich regions degraded in the absence of biomimetic remineralization, with significant decline [p < 0.05] in their complex and storage moduli (E*, 0.83 ± 0.35; E′′, 0.88 ± 0.24; E′, 0.62 ± 0.32). Intrafibrillar apatite deposition preserves the integrity of resin-sparse regions of hybrid layers by restoring their nanomechanical properties to those exhibited by mineralized dentin.