Improved Titanium Implant Attachment in Cortical Bone by Application of rAmelin

Improved Titanium Implant Attachment in Cortical Bone by Application of rAmelin
26 June 2003
C.S. BERNTSEN1, E.A. RIKSEN1, J.E. ELLINGSEN1, I. SLABY2, H.J. R?ÚNOLD1, and S.P. LYNGSTADAAS1, 1 Faculty of Dentistry, University of Oslo, Norway, 2 Biora AB, Malm??, Sweden
IADR
Objective: Amelin is a protein involved in biomineralization of dental hard tissues, secreted by ameloblasts and odontoblasts during tooth formation. The aim of the present study was to investigate if amelin can be utilized to increase the bonding strength between titanium implants and bone in vivo. Methods: 48 coin-shaped grade2 titanium implants with machined surfaces were used. Amelin was dissolved in PGA to a final concentration of 0.2¨µg/¨µl. 24 tests and 24 control implants were placed in the proximal tibia of 12 NewZealandWhite adult female rabbits, two in each tibia,. 10¨µl of rAmelin in PGA or PGA alone were applied on the implant site in a randomised pattern, immediately followed by placement of implants. The implants were covered by a polytetrafluorethylene (PTF) cap and fixed to bone using a pre-shaped titanium band and screws. After eight weeks animals were sacrificed and the tibia with implants were immediately exposed and fixtures and PTF cap was carefully removed. The tibias were then placed in a pull-out test machine. During the pull out test implants were stressed with an increasing force perpendicular to the test surface, at constant speed, until detaching from the bone. A load versus time plot was recorded. After implant detachment, bone liquid from the implant site was collected and analyzed for cytotoxicity by ELISA detection of LDH activity. Results: Average attachment for rAmelin treated implants was 1,6N while controls gave a mean of 1,3 N. PGA showed a mean toxicity value of 2,2 whereas rAmelin produced a mean value of 1,8. Conclusion: Application of rAmelin increased the bonding strength between titanium implants and cortical bone. Moreover, rAmelin treatment was less cytotoxic than PGA alone. The results suggest that application of rAmelin can improve implant attachment in bone. Futher experiments are needed for optimizing conditions for rAmelin improved implant attachment.