This study evaluated the capability of hydroxyapatite fiber (HAF) as a carrier and the bone formation by blending simvastatin. The mixture of HAF and simvastatin (0.15, 0.45, 0.75 mg) was placed in 1 ml of tris-buffer...This study evaluated the capability of hydroxyapatite fiber (HAF) as a carrier and the bone formation by blending simvastatin. The mixture of HAF and simvastatin (0.15, 0.45, 0.75 mg) was placed in 1 ml of tris-buffer and the release of simvastatin from HAF was calculated per 24 hours for 10 days. Bilateral 5 mm-diameter and 3 mm-hight Teflon chambers were fixed on calvaria of adult Japanese white rabbits and filled with 40 mg HAF which containing simvastatin (0, 0.15, 0.45, 0.75 mg). The animals were sacrificed at 4 and 8 weeks and calculated radiologically by Micro-CT. After dyeing by toluidine blue the samples were analyzed histologically. In all of the study groups approximately 25% of simvastatin was released until 10 days. The new bone volume ratio measured by Micro-CT of 4 and 8 weeks group was (22.4%, 21.3%, 41.6%, 26.3%) and (20.2%, 11.7%, 42.1%, 31.2%) in different doses respectively. The 0.45 mg group showed significantly higher new bone volume ratio than 0 mg group and 0.15 mg group. The histological measurement and observations also supported these results. In conclusion, the HAF could be used as a carrier for simvastatin. Combinations of HAF and simvastatin have the potentiality to stimulate new bone formation and approximately 0.45 mg simvastatin in 40 mg HAF is the optimal dose in rabbit chamber model.展开更多
Soft tissues are important for aesthetic considerations in implant therapy. The purpose of this study was to investigate soft tissue augmentation by using porous poly-DL-lactic acid (PDLLA)shaped as a tablet, with a d...Soft tissues are important for aesthetic considerations in implant therapy. The purpose of this study was to investigate soft tissue augmentation by using porous poly-DL-lactic acid (PDLLA)shaped as a tablet, with a diameter of5.0 mmand a height of2.0 mm. Porous PDLLA was implanted between the periosteal and epithelial tissues in 25 rats that were sacrificed at 1, 2, 4, 12, and 24 weeks. The average height of the PDLLA scaffolds at approximately 24 weeks was 1.85 ±0.08 mm, and the molecular weight decreased with time. Sinusoidal capillaries at 1 week, connective tissues at 4 weeks, and necrotic tissues at 24 weeks were observed more than other periods. At 24 weeks, the connective tissue surviving in the pores was confirmed to contain blood vessels;therefore, blood vessels are considered to be critical for the survival of soft tissue in scaffold pores. In this study, PDLLA was found to be useful for soft tissue augmentation in the long term. Although the molecular weight of PDLLA decreased with time, the height of the PDLLA scaffolds was preserved. The connective tissue surviving in the pores of the scaffolds at 24 weeks were associated with blood vessels. Further studies are necessary to investigate the optimal scaffold shape and surface characteristics to improve the penetration of blood vessels.展开更多
文摘This study evaluated the capability of hydroxyapatite fiber (HAF) as a carrier and the bone formation by blending simvastatin. The mixture of HAF and simvastatin (0.15, 0.45, 0.75 mg) was placed in 1 ml of tris-buffer and the release of simvastatin from HAF was calculated per 24 hours for 10 days. Bilateral 5 mm-diameter and 3 mm-hight Teflon chambers were fixed on calvaria of adult Japanese white rabbits and filled with 40 mg HAF which containing simvastatin (0, 0.15, 0.45, 0.75 mg). The animals were sacrificed at 4 and 8 weeks and calculated radiologically by Micro-CT. After dyeing by toluidine blue the samples were analyzed histologically. In all of the study groups approximately 25% of simvastatin was released until 10 days. The new bone volume ratio measured by Micro-CT of 4 and 8 weeks group was (22.4%, 21.3%, 41.6%, 26.3%) and (20.2%, 11.7%, 42.1%, 31.2%) in different doses respectively. The 0.45 mg group showed significantly higher new bone volume ratio than 0 mg group and 0.15 mg group. The histological measurement and observations also supported these results. In conclusion, the HAF could be used as a carrier for simvastatin. Combinations of HAF and simvastatin have the potentiality to stimulate new bone formation and approximately 0.45 mg simvastatin in 40 mg HAF is the optimal dose in rabbit chamber model.
文摘Soft tissues are important for aesthetic considerations in implant therapy. The purpose of this study was to investigate soft tissue augmentation by using porous poly-DL-lactic acid (PDLLA)shaped as a tablet, with a diameter of5.0 mmand a height of2.0 mm. Porous PDLLA was implanted between the periosteal and epithelial tissues in 25 rats that were sacrificed at 1, 2, 4, 12, and 24 weeks. The average height of the PDLLA scaffolds at approximately 24 weeks was 1.85 ±0.08 mm, and the molecular weight decreased with time. Sinusoidal capillaries at 1 week, connective tissues at 4 weeks, and necrotic tissues at 24 weeks were observed more than other periods. At 24 weeks, the connective tissue surviving in the pores was confirmed to contain blood vessels;therefore, blood vessels are considered to be critical for the survival of soft tissue in scaffold pores. In this study, PDLLA was found to be useful for soft tissue augmentation in the long term. Although the molecular weight of PDLLA decreased with time, the height of the PDLLA scaffolds was preserved. The connective tissue surviving in the pores of the scaffolds at 24 weeks were associated with blood vessels. Further studies are necessary to investigate the optimal scaffold shape and surface characteristics to improve the penetration of blood vessels.
