Examination of the bone-metal interface of titanium implants coated by the microwave plasma chemical vapor deposition method.
OBJECTIVE
Diamond layers can be plated with microwave plasma chemical vapor deposition (MWP-CVD) treatment on metal bases such as titanium-aluminum-vanadium alloy (Ti-6Al-4V). The bonding strength of the diamond layer to the metal base is very high, so that no fissures and partial loss of coating take place-well known phenomena that may occur with other coatings in tribologic material testing. In an experimental study using 40 New Zealand White rabbits, a new method for coating implant material was tested for stability of the bone-metal interface.


METHODS
The results of histomorphometric and biomechanical evaluation of coated and uncoated probes implanted in the distal femur of 40 rabbits were compared. The animals were divided into 3 groups, with observation times of 42, 84, and 168 days.


RESULTS
The bone-implant contact was 5% to 18% less in coated than in uncoated probes. Only the early group, with 42 days healing time showed significant differences. Values for the pull-off force of uncoated material were about 3 to 4 times higher than coated material (diamond layer = 2.7 microm). The force increased 2 to 3 times when 200-nm coatings were tested. Electron microscopy detected undercuts of the rough surface that were obturated by diamond when the coating was too thick.


CONCLUSIONS
Diamond-coated material seems to have no corrosion problems in contrast to all other known implant material.


CONCLUSIONS
An inert diamond layer on a metal base can become osseointegrated. Biomechanical stability increased by thinning the diamond coating.
Rupprecht
Stephan
S
Department of Oral & Craniomaxillofacial Surgery, Friedrich-Alexander-University of Erlangen-Nuremberg, Erlangen, Germany. stephan.rupprecht@mkg.imed.uni-erlangen.de
Bloch
Alexandra
A
Rosiwal
Stefan
S
Neukam
Friedrich W
FW
Wiltfang
Joerg
J
D000497:Alloys; D000818:Animals; D020099:Coated Materials, Biocompatible; D003343:Corrosion; D003722:Dental Alloys; D015921:Dental Implants; D020878:Device Removal; D018130:Diamond; D005260:Female; D005269:Femur; D020007:Implants, Experimental; D008422:Materials Testing; D008872:Microwaves; D023421:Models, Animal; D016348:Osseointegration; D011817:Rabbits; D018709:Statistics, Nonparametric; D013499:Surface Properties; D014025:Titanium
D000497:Alloys; D020099:Coated Materials, Biocompatible; D003722:Dental Alloys; D015921:Dental Implants; C031462:titanium alloy (TiAl6V4); D018130:Diamond; D014025:Titanium