title: PTH [1-34] enhances bone response around titanium implants in a rabbit model of osteoporosis.
abstract: BACKGROUND
  Dental implant osseointegration can be impaired in medical conditions with low bone mass, such as glucocorticoid-induced osteoporosis. Intermittent human parathyroid hormone (PTH) [1-34] administration has shown relevant anabolic bone activity in various animal models of osteoporosis. Therefore, we studied the effects of intermittent PTH [1-34] on bone response around titanium implants in experimental osteoporosis induced by ovariectomy and glucocorticoid administration.
  
  
  METHODS
  Titanium dental implants were placed in the proximal tibia metaphysis in 38 animals. Twenty-eight rabbits had undergone bilateral ovariectomy and further methylprednisolone administration for 4 weeks to induce osteoporosis. Ten healthy rabbits were used as controls. At week 8, osteoporotic rabbits started saline vehicle or intermittent PTH administration for 12 weeks. Bone mineral density (BMD) was assessed in peri-implant area, lumbar spine, and global and subchondral knee bone at baseline, and weeks 6 and 20. Animal sacrifice was carried out at week 21. Afterward, tibiae were removed for μCT morphometry and undecalcified sections were evaluated by light and scanning electron microscopy.
  
  
  RESULTS
  PTH increased bone-to-implant contact compared with control rabbits or vehicle administration in osteoporotic rabbits (P < 0.005). PTH-induced new bone formation around external and internal surfaces of titanium implants led to a significant increase of BMD at peri-implant area in osteoporotic rabbits at week 20, when compared with vehicle (P < 0.005). Likewise, PTH increased BMD in other analysed regions.
  
  
  CONCLUSIONS
  Intermittent administration of PTH [1-34] enhances the bone response around titanium implants in a rabbit model of ovariectomy and glucocorticoid-induced osteoporosis.
authors.affiliation: Department of Dentistry, IIS Fundación Jiménez Díaz, Universidad Autónoma, Madrid, Spain.
authors.forename: M Isabel
authors.initials: MI
authors.lastname: Almagro
authors.forename: Jorge A
authors.initials: JA
authors.lastname: Roman-Blas
authors.forename: Miriam
authors.initials: M
authors.lastname: Bellido
authors.forename: Santos
authors.initials: S
authors.lastname: Castañeda
authors.forename: Raul
authors.initials: R
authors.lastname: Cortez
authors.forename: Gabriel
authors.initials: G
authors.lastname: Herrero-Beaumont
mesh_terms: D000818:Animals; D015519:Bone Density / Q000187:drug effects*; D004195:Disease Models, Animal; D005260:Female; D005938:Glucocorticoids; D020007:Implants, Experimental; D008775:Methylprednisolone; D016348:Osseointegration / Q000187:drug effects*; D010024:Osteoporosis / Q000188:drug therapy* / Q000209:etiology; D010052:Ovariectomy; D010281:Parathyroid Hormone / Q000494:pharmacology*; D011817:Rabbits; D013499:Surface Properties; D013977:Tibia / Q000000981:diagnostic imaging / Q000601:surgery; D014025:Titanium / Q000737:chemistry; D055114:X-Ray Microtomography
chemical_list: D005938:Glucocorticoids; D010281:Parathyroid Hormone; D014025:Titanium; D008775:Methylprednisolone