Efeito da isotretinoína no reparo de defeitos ósseos em calota craniana: estudo em ratos

• Ano de defesa: 2009
• Autor(a) principal: Oliveira, Henrique Telles Ramos de
• Orientador(a): Silva, Daniela Nascimento
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Pontifícia Universidade Católica do Rio Grande do Sul; Porto Alegre
• Palavras-chave em Português: ODONTOLOGIA; TRAUMATOLOGIA BUCOMAXILOFACIAL; REPARAÇÃO ÓSSEA (ODONTOLOGIA); VITAMINA A; ISOTRETINOÍNA; ANIMAIS - EXPERIÊNCIAS; TECIDO ÓSSEO
• Link de acesso: http://hdl.handle.net/10923/522

Isotretinoin is a vitamin A derivative that is indicated for dermatologic treatment in patients with severe acne, which shows various side effects on bone metabolism. The aim of the present study was to evaluate the bone repair process in cavities made in the calvarial bone of rats, submitted to oral administration of 7. 5 mg/kg/day isotretinoin, and to determine the serum calcium level in blood samples of the retro-orbital plexus before drug administration and on day of euthanasia. Thirty-three male albino rats (Rattus novergicus albinus, Wistar) were used, which were approximately 60 days old and weighed 250 to 500 g; they were distributed randomly into two groups, control (n=15) and experimental (n=18). A cavity of 2 mm in diameter was made in the calvarial bone of each animal. The animals were killed at 21, 28 and 90 days postoperative. The parietal bone, containing the cavity previously made, was removed and the surgical pieces were submitted to histological processing, followed by H&E staining. Computerized histomorphometric analysis was performed to determine the area of neoformed bone relative to the total defect area at different times of observation. The results expressed as mean percent of neoformed bone in the experimental group were: 25. 37% (± 9. 14) at 21 days, 41. 78% (±7. 00) at 28 days, and 57. 51% (±11. 62) at 90 days. In the control group the results were 17. 10% (±9. 23) at 21 days, 34. 42% (±7. 70) at 28 days, and 48. 49% (±16. 40) at 90 days. Therefore, bone neoformation was greater in the experimental group, but the difference versus control was not statistically significant (p≤0. 05). The serum calcium level showed a statistically significant decrease between the first and second blood sampling in all groups. Based on the results of this study, it was concluded that, despite not being statistically significant, isotretinoin promoted acceleration in the process of bone neoformation in the calvarial bone of rats, along with a reduction in serum calcium levels.