OP 87. OSSI- an in-Vivo Model for Experimental Evaluation of Bone-Titanium Contact

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T. Harangozó, G. Hriczó-Koperdák, S. Farkasdi, S. Koncz, D. Pammer, A Kocsis, G. Varga, J. Blazsek, M. Berardini

Chair(s): Norbert Németh, Ivo Post & Thomas Hubert

10:30 - 10:40h at Buda Room (B)

Categories: Innovative Surgical Research, Novel Techniques and Product, Oral Session

Session: Oral Session X - Innovative Surgical Research

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Background
Osseointegration is a direct, rigid fixation of titanium implants within the bone. Non-invasive and invasive methods are available to measure implant stability. A new experimental model was developed at our department to evaluate osseointegration and new bone formation, named OSSI. Up till now, only tangentional fixation force could be measured, but in the past few months we succeeded in the adaptation of our model to a non-invasive method - Resonance Frequency Analysis (RFA).

Material and Methods
51 female Wistar rats were used in our study (ethical permission No. 1799/003/2009). Screw type titanium implants were fabricated what enabled us to measure implant stability by RFA. An axial cavity (diameter 1.3 mm) for implant placement was drilled into the exposed joint surface of rat tail vertebrae. 4, 8 and 16 weeks after surgery, rats were sacrificed under Nembutal anesthesia and caudal vertebrae were harvested. Implant stability was measured using a non-invasive system utilizing RFA (Osstell, Sweden). Stability was displayed in ISQ (Implant Stability Quotient). Biomechanical properties were further characterized by measuring the maximum extraction force.

Result
The average values of RFA were 23.98, 34.66 and 52.85 ISQ. The outcome of the pull-out test has shown 24, 56.16 and 116.125 Newtons in average.

Conclusion
We established to calculate the value of titanium implant fixation with bone surface. Our study
may provide such results to the clinics of orthopedic traumatology as well as dentistry, which are essential in validating the bone-implant contact, and designing implantological procedures.