The aim of the investigation was to evaluate the effect of implant topography and chemistry on osseointegration in poor quality bone. The study also evaluated a novel ovine mandible model to simulate poor quality trabecular bone.
Method:
36 implants, consisting of two commercially pure (cp) titanium implants (Ti) with different topography (Sand-blasted Large-grit and Acid-etched (SLA) and SLA-modified surface (SLA-mod)) and one titanium-zirconia-alloy (Ti-Zr-alloy) implant with SLA-modified surface, were implanted bilaterally into the angle of the mandible of six sheep. The implants and surrounding tissue were collected at 2,5 and 10 weeks and was analyzed with micro-computed tomography (Micro-CT) analysis, histological/ histomorphmetrical analysis and Scanning electron microscopy (SEM). Statistics analysis consisted of 2-way ANOVA (P≤0.05).
Result:
The quantitative Bone-To-Implant contact (BIC) analysis (mean±standard deviation) of the central 4 threads of the implants at 2/5/10 weeks were as follows: cp-Ti SLA 19.02 ±16.68/ 45.43±381/ 49.58±5.88, cp-Ti SLA-mod 35.57±9.52/ 50.54±13.48/ 74.70±10.35, Ti-Zr-alloy SLA-mod 29.31±10.46/ 52.65±15.29/ 66.51±13.81. There were statistically significant increases in BIC for all surfaces between 2 and 10 weeks, however no statistically significant differences were found between BIC values for the different implant types at any time point. The trend however was for higher BIC values with SLA -mod surfaces for both the cp-Ti and Ti-Zr-alloy implants compared to cp-Ti SLA surface implants. The BIC results were supported by qualitative SEM and Micro-Ct assessment of new bone formation. Histological assessment indicated poor quality trabecular bone in the retro-molar region of the ovine mandible.
Conclusion:
Our results show that the change in core material from cp-Ti to Ti-Zr-alloy had no effect on implant osseointegration in poor quality bone.