Local effect of simvastatin combined with different osteoconductive biomaterials and collagen sponge on new bone formation in critical defects in rat calvaria

Abstract Purpose To evaluate the local effect of simvastatin (SVT) combined with deproteinized bovine bone (DBB) with hydroxyapatite/β-tricalcium phosphate biphasic ceramics (HA/TCP) and with collagen sponge (CS) on bone repair in critical size defects (CSDs) in rat calvaria. Methods Forty-two 5-mm diameter CSDs were made bilaterally in the calvaria of 18 rats. The animals were allocated according to the type of biomaterial and associations used to fill the CSD. After 8 weeks, the animals were euthanized, and their calvaria were evaluated for repaired tissue composition using histologic and histometric analyses. Results In the histometric analysis, the use of SVT showed to increase bone formation in the CSDs when combined with all the bone substitutes tested in this study (p<0.05). Greater bone formation was observed in the groups with SVT compared to the groups without SVT. Conclusions The use of SVT without the need for a vehicle and combined with a commercially available biomaterial may be a cheaper way to potentiate the formation of bone tissue without the need to produce new biomaterials. Therefore, SVT combined with DBB induced significantly greater new bone formation than did the other treatments.

Simvastatin and biphasic calcium phosphate affects bone formation in critical-sized rat calvarial defects

ABSTRACT PURPOSE: To investigate the effects of locally applied simvastatin plus biphasic calcium phosphate (BoneCeramic(r)) or collagen sponge on bone formation in critical-sized bone defects. METHODS: Thirty defects of 5mm in diameter were created bilaterally with a trephine bur in the calvariae of fifteen Wistar rats. The defects were divided into five groups: group 1 - control, no treatment; group 2 (BoneCeramic(r)); group 3 (BoneCeramic(r) + 0.1mg simvastatin); group 4 (collagen sponge); and group 5 (collagen sponge + 0.1mg simvastatin). After eight weeks the animals were euthanized and their calvariae were histologically processed. Hematoxylin and eosin-stained sections were subjected to histological and histomorphometrical analyses. The area of newly formed bone was calculated and compared between groups. RESULTS: The greater amount of a bone-like tissue was formed around the carrier in group 3 (BoneCeramic(r) + 0.1mg simvastatin) followed by group 2 (BoneCeramic(r)), and almost no bone was formed in the other groups. Group 3 was significantly different compared to group 2, and both groups were significantly different compared to the other groups. CONCLUSION: Simvastatin combined with BoneCeramic(r) induced significantly greater amounts of newly formed bone and has great potential for the healing of bone defects.

Behavioural and cognitive effects of simvastatin dose used in stimulation of bone regeneration in rats

To analyze the effects of simvastatin (SVT) in the locomotion, anxiety and memory of rats, as a reflection of the administration of a minimum dose capable of stimulating bone regeneration in defects in the calvariae. METHODS: Surgical procedures were performed in 15 female Wistar rats, 2-month old, to insert the grafting material regenerator (Bone-ceramic(r)) and/or SVT, followed by behavioural and cognitive assessments in the 7th, 30th and 60th days post surgery. RESULTS: The SVT locally applied with the goal of bone regeneration in defects created in rat calvariae does not interfere with locomotion, anxiety levels and/or memories of rats, except for the first week following surgery, when an anxiolytic effect was observed, as a result of a possible central action. CONCLUSION: Failure to provoke any response within 30 and 60 days post surgical procedures suggests that SVT may constitute a good choice in stimulating bone regeneration without affecting the long term neural functions.

Dimensão e composição das distâncias biológicas em dentes e implantes / Dimension and composition of biological width around natural teeth and osseointegrated implants: a review

Atualmente, a Implantodontia é uma opção de tratamento de caráter inegável, com efetiva comprovação técnica e científica. Por ser considerado um excelente substituto artificial da raiz dentária, o implante merece abranger o máximo de pesquisas, a fim de oferecer esclarecimentos e otimizar os resultados com esta terapia. Objetivos: este artigo objetivou revisar a literatura atual relacionada à composição e a dimensão do espaço biológico ao redor dos dentes naturais e implantes osseointegrados, bem como identificar os fatores que podem influenciar o desenvolvimento e a estabilidade desta dimensão biológica ao redor dos implantes. Métodos: artigos de língua inglesa relacionados ao tema, publicados entre 1961 e 2009, foram identificados utilizando-se o Medline e os seguintes unitermos: peri-implant sulcus, periodontal parameters, vertical and horizontal distances teeth implants, papilla. Os mesmos foram relacionados e discutidos considerando-se cada um dos possíveis fatores que interferem na dimensão e composição das distâncias biológicas em dentes e implantes osseointegrados. Conclusão: a literatura revisada aponta a existência de um espaço biológico ao redor dos implantes, e este constitui uma unidade fisiológica estável semelhante àquela encontrada ao redor dos dentes. O tecido gengival e a mucosa peri-implantar apresentam algumas características comuns, sendo diferentes em aspectos como composição do tecido conjuntivo, direcionamento das fibras colágenas e número de vasos sanguíneos.

Currently, dental implants are a treatment option with scientific and technical evidence. To be considered an excellent substitute of the artificial dental root, the implant deserves to enclose maximum of research in order to offer greater clarification and better results. Objectives: The aim of this study was to make a literature review on the composition and dimensions of biological width around natural teeth and osseointegrated implants, and to identify the factors which may influence the development and stability of these distances as well. Methods: articles in the English language published between 1961 and 2009 were electronically identified at Medline using the following uniterms: "peri-implant sulcus", "periodontal parameters", "vertical and horizontal distances", "teeth", "implants", and "papilla". They were related and discussed considering the factors which influence biological distances around teeth and implants. Conclusions: This literature review concluded that: 1) there is a biological width around implants and this constitutes a stable physiological unit similar to that found around teeth; 2) the gingival tissue and the peri-implant mucosa present some common characteristics, but they differ in some aspects, such as composition of connective tissue, direction of collagen fibers and number of blood vessels.