Roughness and Bonding Strength of Bioactive Apatite Layer on Dental Implants

Roughness and Bonding Strength of Bioactive Apatite Layer on Dental Implants
June 2004
Nogueras-Bayona, Joaquim PhD*; Gil, Francesc Javier PhDÇƒÜ; Salsench, Joan PhDÇƒ?; Martinez-Gomis, Jordi PhD¨?
Implant Dentistry: Volume 13(2) June 2004 pp 185-189
Lippincott Williams & Wilkins
*Associate Professor, Section of Prosthodontics, Faculty of Dentistry, University of Barcelona, Barcelona, Spain.
ÇƒÜProfessor, Department of Materials Science and Metallurgy, ETSEIB, Technical University of Catalonia, Barcelona, Spain. Çƒ?Professor, Section of Prosthodontics, Faculty of Dentistry, University of Barcelona, Barcelona, Spain.
¨?Associate Professor, Section of Prosthodontics, Faculty of Dentistry, University of Barcelona, Barcelona, Spain.
Reprint requests and correspondence to: Joaquim Nogueras-Bayona, PhD, Universitat de Barcelona, Facultat d'Odontologia Campus de Bellvitge, C/Feixa Llarga s/n, 08907 L'Hospitalet de Llobregat, Barcelona, Spain, E-mail: quimnogueras@ub.edu
Abstract TOP
This study examined the roughness and bonding strength of the chemical-made apatite layer in comparison with the titanium surface and the plasma-sprayed apatite. Commercially pure titanium plates were heated and chemically treated to deposit crystalline apatite on their surface. The roughness of the titanium surface of the original samples and the apatite surface was analyzed by a roughness surface tester. A scratch test was used to compare the adhesion of the chemical apatite layer to the titanium with the adhesion of a plasma-sprayed layer. A dense bone-like apatite layer was formed on the surface of the titanium by a simple chemical method. The surface roughness test showed that the chemical apatite coating increased the roughness of the samples. The scratch test showed that the bonding strength of the chemical-made apatite coatings to the titanium substrate was higher than the plasma-sprayed apatite coatings. The apatite layer produced by chemical treatment did not show a lower roughness than the titanium substrate. This chemical apatite layer also bonded tighter to the titanium than the plasma-sprayed apatite. This chemically made apatite coating is expected to provide a long-term implant-bone fixation.
The commercially pure titanium implants coated with a plasma-sprayed hydroxyapatite layer are provided with bioactive surface properties and bone-bonding ability. 1 However, the plasma-sprayed technique does not allow accurate control of the chemical composition and the crystallographic structure of the coating. As a result, the apatite layer is mechanically and chemically unstable, and it bonds weakly to the substrate. 2
It was recently demonstrated by Kokubo 3 that an in vitro bone-like apatite deposited on cp Ti could be induced by a chemical treatment. This apatite layer was integrated with the metallic substrates, and it did not have the problems associated with the plasma-spray technique. Kokubo's method showed that chemical treatment produced a uniform bioactive apatite layer on the surface of the titanium. 4 The first purpose of this study was to evaluate how this new apatite layer changed the roughness of the implant surface.
The second purpose of this study was to examine the bonding strength of the hydroxyapatite layer obtained by chemical treatment to the Ti substrate. The results are discussed in comparison with those of plasma-sprayed hydroxyapatite.
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