Intermittent administration of parathyroid hormone improves the repairing process of rat calvaria defects: a histomorphometric and radiodensitometric study

• Eduardo-de-Paula Silva ^[4] ; Daniel-Fernando-Pereira Vasconcelos ^[5] ; Marcelo-Rocha Marques ^[4] ; Marco-Antônio Dias da Silva ^[1] ; Flávio-Ricardo Manzi ^[2] ; Silvana-Pereira Barros ^[3]
  1. [1] Universidade Federal de Campina Grande

     Universidade Federal de Campina Grande

     Brasil

     
  2. [2] Pontifícia Universidade Católica de Minas Gerais

     Pontifícia Universidade Católica de Minas Gerais

     Brasil

     
  3. [3] University of North Carolina at Chapel Hill

     University of North Carolina at Chapel Hill

     Township of Chapel Hill, Estados Unidos

     
  4. [4] University of Campinas, Brasil
  5. [5] Federal University of Piauí, Brazil

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• Localización: Medicina oral, patología oral y cirugía bucal. Ed. inglesa, ISSN-e 1698-6946, Vol. 20, Nº. 4 (julio), 2015
• Idioma: inglés
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• Resumen

  • Background: The aim of this study was to evaluate the effects of intermittent treatment of parathyroid hormone (PTH (1-34)) on the bone regeneration of critically-sized rat calvarial bone defects.

    Material and Methods: Thirty-two male rats were trephined (4mm fullthickness diameter), in the central part of the parietal bones and divided into 2 groups of 16. The PTH group received subcutaneous injections of PTH (1-34) at 40μg/kg, 3 times a week and the control (CTL) group received the vehicle in the same regimen. The rats were sacrificed at 4 weeks post-treatment regimen, the parietal bones were extracted and samples were evaluated through histomorphometry and radiodensitometry.

    Results: The histological observations showed that the PTH group presented more “island-like” new bone between the defect margins with fibrous tissues than did the CTL group. The PTH group significantly exhibited greater histologic bone formation than did the CTL group (1.5mm ±0.7; 1.9 mm ± 0.6, p <0.05/ for residual bone defect). The radiodensitometry analysis revealed significant differences among the PTH and CTL groups (2.1 Al eq. ±0.04;

    1.8Al eq. ±0.06, p <0.05), demonstrating an increase in bone mineral density. The PTH treatment contributed to the bone formation with a higher amount of mineral and/or fibrous tissue when compared with the CTL group.

    Conclusions: The results suggest that it was possible to increase the process of bone regeneration by accelerating the healing process in rat calvarial defects through intermittent administration of the PTH treatment.