EFFECT OF IMPLANT MATERIAL AND SURFACE CHARACTERISTICS ON THE SURFACE AND MECHANICAL PROPERTIES OF DENTAL IMPLANTS

UoM administered thesis: Phd

  • Authors:
  • Eman Abuhajar

Abstract

Implant material and surface properties are critical factors that determine implant success. Commercially pure titanium and its alloys are considered the gold standard. However, they still have some limitations. Different approaches have been used to improve and accelerate healing through modifying the implant surfaces. Surface modifications will render the implant with different surface topographies and chemical composition compared to the underlying material, and bioceramic treatments are known to enhance the bioactivity of implant surfaces. The aim of this study was to investigate the effect of the implant material and surface modifications on selected surface and mechanical properties. The surface roughness of commercially pure titanium (CpTi) and titanium-zirconia (TiZr) alloy with different surfaces were investigated. The results revealed that implant material and surface modification had a significant effect on the mean roughness parameters Sa and Ra (p = 0.002 and 0.002, respectively). Nanoindentation and micro–nanoindentation testing was used to assess the effect of manufacturing processes on the bulk material sub-surface hardness and elastic modulus. It was found that the manufacturing process had a significant effect on material sub-surface elastic modulus at both nano and micro-nano levels (p= 0.006, and 0.001, respectively), and nano and micro-nano hardness (p= 0.002, and 0.010, respectively). In the TiZr alloy group there was a general tendency for increased hardness and decreased elastic modulus compared to CpTi. Air abrasion treatment of the CpTi and TiZr surfaces with calcium phosphate abrasives resulted in a non-uniform distributed coating. Surface analysis using optical profilometry, (SEM-EDS) confirmed the incorporation of CaP powders and the change of surface properties. Surface characterisation revealed no significant differences in Ca/P weight percentages, Sa and Ra parameters between different implant materials, or surfaces using different powder compositions. Dissolution of the deposited CaP powders from different implant materials and surfaces in deionised water were examined. The calcium and phosphorous ions continued to release for 3 weeks. More investigations of different alloys and treatments are needed before considering the optimum implant material and surface.

Details

Original languageEnglish
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Award date3 Jan 2020