The removal of implant coatings may be necessary if rough implant surfaces
are exposed subgingivally due to progressive peri-implant bone loss or if t
hey are also supragingivally exposed because of progressive gingival recess
ion, thus facilitating plaque formation and impairing tooth cleaning done a
t home. The aim of this experimental study was to develop diamond-coated fi
les and rubberized polishers for machine-driven instrumentation of implant
cylinders, and present an instrumentation concept for the complete removal
of rough titanium plasma spray (TPS) and hydroxylapatite (HA) layers and po
lishing exposed titanium surfaces. The surface structure and its possible c
ontamination by the instrumentation process was investigated using laser pr
ofilometry, scanning electron microscopy, and x-ray fluorescence analysis.
The effect of impurities on the growth of human fibroblasts was tested in c
ell culture. The results show that TPS and HA implant coatings can be remov
ed with the modified implant files. After polishing the exposed titanium su
rfaces, roughness depths of Rz= 4.6 mum (TPS) and Rz=5.7 mum (HA) and, for
implant cylinders, 3.4 mum were found. During the instrumentation of implan
t surfaces, contamination with the material of the instrument must be expec
ted. It was shown that, in principle, growth of human gingival fibroblasts
on the instrumented surfaces is possible. The cells were intimately associa
ted with one another and, compared to culture controls, demonstrated good a
dhesion with strict orientation to the microstructure of the scoring left b
y instrumentation. The biological consequences and mechanisms of cell adhes
ion on instrumented surfaces require further investigation.