Original Article
Nanomechanical properties and molecular structures of in vitro mineralized tissues on anodically-oxidized titanium surfaces

https://doi.org/10.1016/j.nano.2013.09.007Get rights and content

Abstract

The biomechanical stability of mineralized tissues at the interface between implant surface and bone tissue is of critical importance. Anodically oxidized titanium prepared in a chloride solution results in enhanced mineralization of adherent osteoblasts and has antimicrobial activity against oral microorganisms. We evaluated the nanomechanical properties and molecular structures of the in vitro mineralized tissues developing around anodically oxidized titanium surfaces with and without preparation in chloride solution. Anodically oxidized titanium surfaces showed superior osteogenic gene expressions than those of thermally oxidized and bare titanium surfaces. Preparation of anodically oxidized titanium in chloride enhanced the production of mineralized tissue around it. However, the mineralized tissue around anodically oxidized titanium prepared without chloride had increased mineral:matrix and cross-linking ratios, resulting in higher hardness and lower elasticity.

From the Clinical Editor

In this study anodically oxidized titanium was used to enhance the biomechanical stability of mineralized tissues at the implant surface -- bone tissue interface. The mineralized tissue around anodically oxidized titanium prepared without chloride had increased mineral:matrix and cross-linking ratios, resulting in higher hardness and lower elasticity.

Graphical Abstract

The surface morphology of anodically oxidized titanium examined using (A) a scanning electron microscope and (B) a laser microscope.

  1. Download : Download high-res image (141KB)
  2. Download : Download full-size image

Section snippets

Sample preparation

JIS grade 2 titanium (KS-50; Kobe Steel, Tokyo, Japan) was prepared with dimensions of 10 × 10 × 1.0 mm. The surface of each specimen was mechanically polished under running water using waterproof polishing papers (up to #1200 grit) before finishing with 0.3 μm diameter alumina particles. Prepared specimens were ultrasonically cleaned in acetone/detergent solution (7X; ICN Biomedicals, Aurora, OH, USA) and pure distilled water for 15 min, then dried and stored in a sealed desiccator for 1 week at

Surface topography

Pores with diameters in the micron or submicron scale were counted on Ao-Ti, whereas granular deposits forming on the Ti-Cl surface were quantitated. The mean surface roughness parameters are summarized in Table 2. The height parameters of both anodically oxidized Ao-Ti and Ti-Cl were higher than those of Ti and Ho-Ti.

XPS

The relative atomic concentration of each element on the titanium samples is shown in Table 3. The energy position of Cl2p on Ti–Cl was detected at 201.4 eV (not shown). Therefore,

Discussion

Both surface chemistry and topography have been advocated as critical indicators on anodically oxidized titanium.33, 34 The present study elucidates biological activities such as gene expression and mineralization of primary osteoblasts enhanced presumably by respective surface parameters on anodically oxidized titanium prepared with or without chloride solution.

We have demonstrated the developing thickness of a titanium oxide layer observed on thermally oxidized Ho-Ti and anodically oxidized

References (38)

  • X. Bi et al.

    Raman and mechanical properties correlate at whole bone- and tissue-levels in a genetic mouse model

    J Biomech

    (2011)
  • T. Suda et al.

    Role of 1α,25-dihydroxyvitamin D3 in osteoclast differentiation and function

    Methods Enzymol

    (1997)
  • L. Angker et al.

    Characterising the micro-mechanical behaviour of the carious dentine of primary teeth using nano-indentation

    J Biomech

    (2005)
  • O.M. Omar et al.

    The stimulation of an osteogenic response by classical monocyte activation

    Biomaterials

    (2011)
  • Y.T. Sul et al.

    Characteristics of the surface oxides on turned and electrochemically oxidized pure titanium implants up to dielectric breakdown: the oxide thickness, micropore configurations, surface roughness, crystal structure and chemical composition

    Biomaterials

    (2002)
  • S.R. Vora et al.

    Lysyl oxidase propeptide inhibits FGF-2-induced signaling and proliferation of osteoblasts

    J Biol Chem

    (2010)
  • H.M. Kim et al.

    Preparation of bioactive Ti and its alloys via simple chemical surface treatment

    J Biomed Mater Res

    (1996)
  • A. Nanci et al.

    Chemical modification of titanium surfaces for covalent attachment of biological molecules

    J Biomed Mater Res

    (1998)
  • Q. Cai et al.

    The effect of electrolyte composition on the fabrication of self-organized titanium oxide nanotube arrays by anodic oxidation

    J Mater Res

    (2005)
  • Cited by (0)

    Author contributions: Y.S. and I-K.J. performed project planning, experimental work, data interpretation and preparation of the manuscript. D.S., Wurihan, Y.T. and K.O. performed experimental work. R.T. and N.F. participated in data analysis. R.K. and T.M. supervised research and participated in project planning.

    Funding sources: This work was supported by a Grant-in-Aid for Scientific Research (B) and a Grant-in-Aid for Scientific Research (C) from the Ministry of Education, Culture, Sports, Science and Technology of Japan. None of the authors have any conflicts of interest to declare.

    View full text