Effect of Different Doses of Synthetic Parathyroid Hormone (1-34) on Bone around Implants: a Preclinical Rat Model

Abstract

The aim of this study was to evaluate the effect of a lower dose of parathyroid hormone- PTH (1-34) on osteogenic potential of bone healing around titanium implants inserted into the tibia of rats. A blind parallel study was conducted in 45 adult male Wistar rats. Each rat received one titanium implant (4.5 x 2.2 mm) and was randomly assigned to receive subcutaneous injections, three times/week for 30 days, of the following treatments: group 1 - 40 µg/kg of PTH (1-34) (n=15); group 2 - 2 µg/kg of PTH (1-34) (n=15) and; group 3 - only the vehicle required for hormone dissolution (n=15). Thirty days after surgery, the animals were sacrificed and specimens containing the implant and the surrounding bone were removed and processed for non-decalcified sections. The sections were evaluated according to the following histometric parameters: proportion of mineralized tissue (PMT) adjacent to the implant threads (500 µm band); bone filling within the limits of the threads (BF) and; bone-to-implant contact (BIC). For the cortical region, both hormone dosages (groups 1 and 2) promoted better results, for all parameters, when compared to control group (p<0.05). Similar results were observed for the BF parameter in the cancellous region (p=0.0394). Therefore, systemic administration of PTH (1-34) stimulates bone formation around titanium implants, even at low doses.

Development of a Novel Nanotextured Titanium Implant. An Experimental Study in Rats

“…We have modified the morphological nanostructure of the implant surface to improve the bioactivity of the materials to develop better osseointegration. In this animal study, the osseointegration level (i.e., bone to implant contact and bone area fraction occupancy) of our novel nanotextured titanium implant was evaluated using micro implants installed in Wistar rats’ tibia, which is commonly used for the bone to implant contact evaluation [21,22].…”