Osseointegration of titanium alloy and HA-coated implants in healthy and ovariectomized animals: a histomorphometric study

Objectives The objective of the present study is to evaluate the response to dental implants in healthy and osteoporotic bone. Materials and methods Ten ovariectomized (OVX) New Zealand rabbits submitted to a hypocalcic diet and 10 sham-aged rabbits were used. All animals were submitted to bone mineral density (BMD) measurements before ovariectomy, and also 4 months afterwards, using dual energy X-ray absorptiometry. The BMD measurements showed a significant loss of bone mass, between the first and second examinations, only in the experimental group (P < 0.05). After the bone mass loss induction period, three different implants were installed in the proximal tibia metaphisis of each animal: a titanium alloy implant (Ti), a plasma-spray hydroxyapatite-coated implant (HA-PS), and another implant coated with hydroxyapatite with the biomimetic process (HA-B). Results After 3 months, histomorphometry showed a bone-to-implant contact (BIC) for Ti implants of 73.09 +/- 13.74% in healthy and 66.09 +/- 30.01% in OVX animals. The BIC for the HA-PS was 64.83 +/- 15.65% and 90.17 +/- 8.14% for healthy and OVX animals, respectively, and 88.66 +/- 5.30% and 87.96 +/- 10.71% for the HA-B implants placed in the same conditions. The differences between the implants in healthy and OVX conditions were not statistically significant (P > 0.05). The only significant difference within groups was observed in the healthy animals between HA-B and Ti implants (P < 0.06). Conclusion Within the parameters used in this animal model it was not possible to observe BIC differences between osteoporotic and healthy animals. To cite this article:Vidigal GM Jr, Groisman M, Gregorio LH, Soares GA.Osseointegration of titanium alloy and HA-coated implants in healthy and ovariectomized animals: a histomorphometric study.Clin. Oral Impl. Res. 20, 2009; 1272-1277doi: 10.1111/j.1600-0501.2009.01739.x.