INTRODUCTION: Micro-organism adhesion and plaque formation
is affected by surface free energy (SFE), surface roughness,
hydrophilicity, surface chemistry, surface charge and
the presence of proteins.
AIMS: The aim of this study was to assess and compare
surface characteristics of surgical grade cobalt chromium
alloy (CCM) and of commercially pure titanium (cpTi).
METHOD: Nine metallic cylinders were machined to precise
standards from each material. Surface roughness was
measured at four different points on each sample and the
average Ra value was calculated for each material. Contact
angles were obtained using the sessile-drop method and
applied in calculating the SFE. Surface hardness was evaluated
by means of a Vickers hardness micro-indentation.
RESULTS: Surface roughness was similar for both metals,but
total SFE values and Vickers surface hardness scores
showed significant differences (p<0.0001). CONCLUSION: SFE analysis showed CCM to be more hydrophobic
and that oral bacteria might therefore be less
adherent than to cpTi. The mean Vickers Hardness scores
of the cpTi were significantly lower (p<0.0001), suggesting
that CCM may be more resistant to surface modifications
and surface roughening, thus remaining smoother with less plaque accumulation than cpTi. This study demonstrated
that CCM might be a suitable alternative implant abutment