Teriparatide improves alveolar bone modelling after tooth extraction in orchiectomized rats.

OBJECTIVE: The aim of this study was to evaluate bone metabolism in the alveolar repair process in orchiectomized male rats treated with teriparatide. MATERIALS AND METHODS: A total of 78 rats were divided into three groups: 26 oriectomized rats treated with teriparatide (ORQTRAT), 26 untreated orchiectomized rats (ORQ), and 26 rats which had undergone sham surgical procedures (SHAM), all these animals underwent extraction of the central incisor tooth. Thus, a histological analysis was performed (42 days). Real Time PCR (14 and 42 days) and immunohistochemical (42 days) analyses were performed based on the expression of RANK-L and osteoprotegerin (OPG). The calcein and alizarin were analyzed via laser confocal microscopy to verify alveolar bone turnover, and microtomographic analysis was performed to determine volume and bone quality (calcified tissues). In this analysis, the euthanasia period was 60 days post-extraction. The quantitative data were submitted to the statistical test and the significance level of 5% was adopted. RESULTS: Teriparatide increased bone turnover with a higher relative gene expression of RANKL and OPG at 14 days, and at 42 days, there was a significant decrease of RANKL and an increase of OPG, this standard can also be evaluated in the ratio of RANKL to OPG. Greater values of area and bone mineral deposition were found for the ORQTRAT group (p < 0.05), along with higher bone volume values (p < 0.05). The immunolabels revealed greater intensity in the relationship of RANKL and OPG, which led to intense remodeling aiding in the process of bone formation. CONCLUSION: The teriparatide treatment in orchiectomized rats increases bone volume and decreases the porosity, in addition to promoting greater intensity in bone turnover during alveolar repair.

Short term sodium alendronate administration improves the peri-implant bone quality in osteoporotic animals.

OBJECTIVE: The aim of this study was to evaluate the bone repair process at the bone/implant interface of osteoporotic rats treated with sodium alendronate through the analysis of microtomography, real time polymerase chain reactions and immunohistochemistry (RUNX2 protein, bone sialoprotein (BSP), alkaline phosphatase, osteopontin and osteocalcin). MATERIAL AND METHODS: A total of 42 rats were used and divided in to the following experimental groups: CTL: control group (rats submitted to fictitious surgery and fed with a balanced diet), OST: osteoporosis group (rats submitted to a bilateral ovariectomy and fed with a low calcium diet) and ALE: alendronate group (rats submitted to a bilateral ovariectomy, fed with a low calcium diet and treated with sodium alendronate). A surface treated implant was installed in both tibial metaphyses of each rat. Euthanasia of the animals was conducted at 14 (immunhostochemistry) and 42 days (immunohistochemistry, micro CT and PCR). Data were subjected to statistical analysis with a 5% significance level. RESULTS: Bone volume (BV) and total pore volume were higher for ALE group (P<0.05). Molecular data for RUNX2 and BSP proteins were significantly expressed in the ALE group (P<0.05), in comparison with the other groups. ALP expression was higher in the CTL group (P<0.05). The immunostaining for RUNX2 and osteopontin was positive in the osteoblastic lineage cells of neoformed bone for the CTL and ALE groups in both periods (14 and 42 days). Alkaline phosphatase presented a lower staining area in the OST group compared to the CTL in both periods and the ALE at 42 days. CONCLUSION: There was a decrease of osteocalcin precipitation at 42 days for the ALE and OST groups. Therefore, treatment with short-term sodium alendronate improved bone repair around the implants installed in the tibia of osteoporotic rats.

Short term sodium alendronate administration improves the peri-implant bone quality in osteoporotic animals

Abstract Sodium alendronate is a bisphosphonate drug that exerts antiresorptive action and is used to treat osteoporosis. Objective The aim of this study was to evaluate the bone repair process at the bone/implant interface of osteoporotic rats treated with sodium alendronate through the analysis of microtomography, real time polymerase chain reactions and immunohistochemistry (RUNX2 protein, bone sialoprotein (BSP), alkaline phosphatase, osteopontin and osteocalcin). Material and Methods A total of 42 rats were used and divided in to the following experimental groups: CTL: control group (rats submitted to fictitious surgery and fed with a balanced diet), OST: osteoporosis group (rats submitted to a bilateral ovariectomy and fed with a low calcium diet) and ALE: alendronate group (rats submitted to a bilateral ovariectomy, fed with a low calcium diet and treated with sodium alendronate). A surface treated implant was installed in both tibial metaphyses of each rat. Euthanasia of the animals was conducted at 14 (immunhostochemistry) and 42 days (immunohistochemistry, micro CT and PCR). Data were subjected to statistical analysis with a 5% significance level. Results Bone volume (BV) and total pore volume were higher for ALE group (P<0.05). Molecular data for RUNX2 and BSP proteins were significantly expressed in the ALE group (P<0.05), in comparison with the other groups. ALP expression was higher in the CTL group (P<0.05). The immunostaining for RUNX2 and osteopontin was positive in the osteoblastic lineage cells of neoformed bone for the CTL and ALE groups in both periods (14 and 42 days). Alkaline phosphatase presented a lower staining area in the OST group compared to the CTL in both periods and the ALE at 42 days. Conclusion There was a decrease of osteocalcin precipitation at 42 days for the ALE and OST groups. Therefore, treatment with short-term sodium alendronate improved bone repair around the implants installed in the tibia of osteoporotic rats.