Local administration of growth hormone enhances periimplant bone reaction in an osteoporotic rabbit model.

OBJECTIVE: The purpose of this study was to determine whether rhGH administered locally during the surgical placement of an implant, in the tibia of an osteoporotic rabbit model, would induce qualitative and quantitative differences in peri-implant bone reaction.

MATERIALS AND METHODS: Eight New Zealand rabbits were ovariectomized and fed with a low-calcium diet (with 0.07% of calcium) to induce osteoporosis. After 6 weeks, an experimental titanium sheet was inserted into the rabbit tibiae. The rabbits were randomly divided into two groups. The experimental group was treated with 4 IU of rhGH added locally into the ostectomy as a lyophilized powder and the control group was left without any treatment. After 2 weeks, animals were sacrificed, tibial sections were prepared and bone-titanium interface was examined at light microscopy, using Masson, hematoxylin-eosin and Pichrosirius stains. Light microscopic morphometry and densitometry were used to comparatively quantitate bone reaction.

RESULTS/CONCLUSION: Local administration of rhGH during the surgical placement of titanium sheets on the tibiae of an osteoporotic rabbit model enhances periosteal and transcortical reaction and mineralization of osteoid 14 days later around titanium sheets, without increasing bone resorption.