Intermittent administration of parathyroid hormone improves bone quality and quantity around implants in rat tibiae

Abstract

Objectives: Intermittent injection of parathyroid hormone (PTH) is used to treat osteoporosis. The concept of bone quality was updated 20 years ago; however, these updates have not been adopted in implant dentistry. This study aimed to investigate the effects of intermittent administration of PTH on bone quality around implants in rat tibiae. Methods: Grade IV-titanium-threaded implants that were 3.5 mm long and 2.0 mm wide were placed in a randomly selected side of the proximal tibiae of 12-week-old female Wistar rats. Three weeks after implant placement, the rats were randomly divided into PTH-administration and saline-injection groups (PTH and VC, respectively; n ¼ 7 per group). Micro-computed tomographical, histomorphometric, and immunohistochemical analyses were performed to evaluate bone quality and quantity surrounding the implants. Results: PTH significantly increased bone volume and bone mineral density in bones not associated with the implants as compared to these values in the VC group. PTH significantly increased bone area and the amount of collagen within the total inside areas of all implant threads compared to that observed in VC. Moreover, PTH significantly increased the number of osteoblasts, osteocytes, and osteoclasts in the total inside and/or outside areas of all implant threads and altered the ratio of type I and III collagen to total collagen fibers. Conclusions: Within the limitations of this study, intermittent administration of PTH improved both bone quantity and bone quality based on the types and numbers of bone cells and the types of collagen fibers surrounding implants placed into rat tibiae.

Effect of intraoral administration of parathyroid hormone on osseous and soft tissue healing around implants in ovariectomized rat maxillae

“…Each q-value associated with the assessment parameters related to soft tissue corresponded to the respective p-value (Table 4). Several animal studies showed increases in bone formation or trabecular bone thickness around implants with systemic intermittent PTH administration (Gao et al, 2022;Mair et al, 2009;Skripitz et al, 2005;Uchida et al, 2020). In those studies, implants were inserted in long bones and in non-osteoporosis conditions.…”

“…According to our previous investigations, bone cells, collagen fibers, and biological apatite have been proven to potentially become determinant factors of bone quality (Kuroshima et al, 2015;Sasaki et al, 2015;Suzue et al, 2022;Uto et al, 2017). Our previous study demonstrated that subcutaneous intermittent PTH administration significantly increased bone volume and BMD, in addition to improved bone quality around implants placed into rat tibiae (Uchida et al, 2020). Moreover, intraoral intermittent PTH administration has been shown to accelerate the osseous and soft tissue healing of tooth extraction sockets in rats (Kuroshima et al, 2013).…”

Progress of Signaling Pathways, Stress Pathways and Epigenetics in the Pathogenesis of Skeletal Fluorosis

“…High doses of PTH promote bone resorption, while at low doses, it stimulates bone formation. Furthermore, animal and clinical studies have revealed that when PTH is given intermittently subcutaneously, it stimulates bone formation, increases bone density in long bones and vertebrae, and improves the bone quality [ 53 , 54 ]. It follows that the use of PTH in the treatment of osteoporosis has been approved by the US Food and Drug Administration and other organizations [ 54 ].…”

The effect of Nanocrystalline Hydroxyapatite -parathyroid hormone mixture on bone defect healing: Experimental Study in Dogs

“…PTH appears to be effective in the treatment of fractures because it speeds up the healing and regeneration processes. (15)(16)(17)(18)(19) Although there was positive effect of PTH, continuous elevation of PTH serum level may lead to catabolic effect in bone. That direct a researchers to provide PTH to the local site to induce the optimum PTH anabolic action and preserve the PTH bioactivity.…”

“…That direct a researchers to provide PTH to the local site to induce the optimum PTH anabolic action and preserve the PTH bioactivity. (18,19) There are few studies evaluating the effect of parathyroid hormone local application as a therapeutic agent for bone healing. This study was conducted to evaluate the histological effect of nanocrystalline hydroxyl apatite mixed with parathyroid hormone on the healing of mandibular bone defect.…”