title: Effect of Recombinant Human Growth Hormone on Osseointegration of Titanium Implants: A Histologic and Biomechanical Study in Rabbits.
abstract: To evaluate the action of recombinant human growth hormone (rhGH) on osseointegration of titanium implants in rabbits. Fourteen adult New Zealand rabbits, aged 30 weeks, were used in the study, and randomly divided into 2 groups. In each animal, 2 (2.2 mm × 6 mm) pure titanium implants were placed in the left tibia. In one group (test group), 1 IU (0.3 mg) of rhGH as a lyophilized powder was applied to each osteotomy site prior to implant placement. Only titanium implants were placed in osteotomy sites of the other group (control). Animals were humanely killed at 14 and 42 days after surgery, and samples were then prepared for histologic analysis and biomechanical test. The biomechanical test showed tensile pull-out stress values of 33.88 N/cm(2) for controls and 59.26 N/cm(2) for the rhGH group at 14 days and 25.99 N/cm(2) and 29.69 N/cm(2) for the control and the test group, respectively, at 42 days. Scanning electron microscope analysis showed more uniform and abundant bone tissue in contact with the implants for the test group at 14 days, and no differences between groups at 42 days. Furthermore, histologic analysis also showed accelerated bone repair in 14 days and a more advanced stage of bone remodeling for the rhGH-treated group when compared to controls after 42 days of repair. Such results show that the topical use of rhGH induces new bone formation in the early stages of bone repair and hence accelerates osseointegration of titanium dental implants.
authors.affiliation: 1  Private practice, Porto Alegre, Brazil.
authors.forename: Marcelo Emir Requia
authors.initials: ME
authors.lastname: Abreu
authors.affiliation: 2  Universidade do Planalto Catarinense, Lages, Brazil.
authors.forename: Renato
authors.initials: R
authors.lastname: Valiati
authors.affiliation: 3  Department of Physics, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: Roberto
authors.initials: R
authors.lastname: Hubler
authors.affiliation: 4  School of Veterinary Medicine, Universidade do Estado de Santa Catarina, Lages, Brazil.
authors.forename: Aury Nunes
authors.initials: AN
authors.lastname: Moraes
authors.affiliation: 5  Oral and Maxillofacial Surgery Department, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: Fernando
authors.initials: F
authors.lastname: Antonini
authors.affiliation: 5  Oral and Maxillofacial Surgery Department, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: Henrique do Couto
authors.initials: Hdo C
authors.lastname: de Oliveira
authors.affiliation: 5  Oral and Maxillofacial Surgery Department, Pontifícia Universidade Católica do Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: Rogério Miranda
authors.initials: RM
authors.lastname: Pagnoncelli
mesh_terms: D000818:Animals; D016723:Bone Remodeling; D015921:Dental Implants; D019382:Human Growth Hormone; D016348:Osseointegration; D011817:Rabbits; D011897:Random Allocation; D013499:Surface Properties; D013977:Tibia; D014025:Titanium
chemical_list: D015921:Dental Implants; D019382:Human Growth Hormone; D014025:Titanium
keywords: bone repair; growth hormone; osseointegration