Treatment of cranial bone defect with demineralized allogeneic matrix and post-extraction tooth socket with heterologous fibrin biopolymer in streptozotocin-induced type 1 diabetic rats

• Ano de defesa: 2023
• Autor(a) principal: Paini, Suelen
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: eng
• Instituição de defesa: Biblioteca Digitais de Teses e Dissertações da USP
• Palavras-chave em Português: Adesivo tecidual de fibrina; Biopolímeros; Biopolymers; Bone matrix; Diabetes mellitus experimental; Fibrin tissue adhesive; Matriz ossea; ratos; Rats
• Link de acesso: https://www.teses.usp.br/teses/disponiveis/25/25149/tde-10112023-170835/

Bone tissue has the ability to regenerate. However, in cases of extensive bone regeneration, bone repair is still a challenge in clinical routine, especially in diabetic patients. This clinical condition may compromise the bone microenvironment/metabolism, resulting in delay/complications during the healing process. Biopolymers have gained great prominence in regenerative medicine due to their biocompatibility, slow degradation, structural similarity with native tissues and bioactivity, which can enhance the repair process and tissue growth. Therefore, the aim of this study was to evaluate the effectiveness of demineralized allogeneic matrix (MAD) and heterologous fibrin biopolymer (HFB) in the treatment of bone defects in an experimental model of type I diabetic rats (DM1) induced by streptozotocin (STZ). In article 1, 8mm diameter cranial defects were performed in the calvaria of 40 normoglycemic (NG) rats and 40 DM1 rats induced by an intraperitoneal injection of 47 mg/kg of STZ. In the NG/MAD and DM1/MAD groups, the defects were filled with MAD and in the NG/BC and DM1/BC groups with a blood clot. After periods of 7, 14, 21 and 42 days, the calvaria were collected and evaluated by histomorphometry. The results showed that in all groups bone formation gradually increased between 7 and 42 days. However, at 42 days, bone formation was higher in the NG/MAD group (3.67 mm2), followed by the NG/BC (1.91 mm2), DM1/MAD (1.16 mm2) and DM1/BC (0.81mm2). In article 2, after extraction of the right incisor of 48 DM1 rats induced with 52 mg/kg of STZ, the alveoli of the DM1/HFB group were filled with HFB and the DM1/BC group with blood clot. After 7, 14, 42 days, the tooth sockets were collected and analyzed under microtomography, histomorphometry, histochemistry (picrosirius red). In animals with blood glucose above 300mg/dL, in both groups, the alveoli showed an inflammatory process at 7 to 14 days, accompanied by a marked reduction in alveolar volume at 42 days. In animals with blood glucose below 280 mg/dL, few inflammatory cells were observed at 7 days and the alveolar reduction was smaller in the DM1/HFB group compared to the DM1/BC group. In conclusion, MAD promotes greater bone gain in cranial defects in both NG and DM1 animals when compared to natural repair (BC). Regarding post-extraction tooth socket healing, HFB leads to greater socket preservation compared to natural repair when glycemic indices are less than 280 mg/dL. Biopolymers show promise in the treatment of craniomaxillofacial bone defect in diabetic patients with poor glycemic control.