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1.
Braz Oral Res ; 33: e079, 2019 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-31531565

RESUMO

Cell therapy associated with guided bone regeneration (GBR) can be used to treat bone defects under challenging conditions such as osteoporosis. This study aimed to evaluate the effect of mesenchymal stem cells (MSCs) in combination with a poly(vinylidene-trifluoroethylene)/barium titanate (PVDF-TrFE/BT) membrane on bone repair in osteoporotic rats. Osteoporosis was induced in female rats by bilateral removal of the ovaries (OVX) or sham surgery (SHAM), and the osteoporotic condition was characterized after 5 months by microtomographic and morphometric analyses. Calvarial defects were created in osteoporotic rats that immediately received the PVDF-TrFE/BT membrane. After 2 weeks, bone marrow-derived MSCs from healthy rats, characterized by the expression of surface markers using flow cytometry, or phosphate-buffered saline (PBS) (Control) were injected into the defects and bone formation was evaluated 4 weeks post-injection by microtomographic, morphometric, and histological analyses. A reduction in the amount of bone tissue in the femurs of OVX compared with SHAM rats confirmed the osteoporotic condition of the experimental model. More bone formation was observed when the defects were injected with MSCs compared to that with PBS. The modification that we are proposing in this study for the classical GBR approach where cells are locally injected after a membrane implantation may be a promising therapeutic strategy to increase bone formation under osteoporotic condition.


Assuntos
Compostos de Bário/farmacologia , Regeneração Tecidual Guiada/métodos , Células-Tronco Mesenquimais/fisiologia , Osteogênese/efeitos dos fármacos , Osteoporose/terapia , Polivinil/farmacologia , Titânio/farmacologia , Animais , Compostos de Bário/química , Densidade Óssea , Regeneração Óssea/efeitos dos fármacos , Regeneração Óssea/fisiologia , Feminino , Citometria de Fluxo , Imagem Tridimensional , Células-Tronco Mesenquimais/química , Osteogênese/fisiologia , Osteoporose/fisiopatologia , Ovariectomia , Polivinil/química , Distribuição Aleatória , Ratos Wistar , Reprodutibilidade dos Testes , Fatores de Tempo , Titânio/química , Resultado do Tratamento
2.
Braz. oral res. (Online) ; 33: e079, 2019. graf
Artigo em Inglês | LILACS-Express | ID: biblio-1019604

RESUMO

Abstract Cell therapy associated with guided bone regeneration (GBR) can be used to treat bone defects under challenging conditions such as osteoporosis. This study aimed to evaluate the effect of mesenchymal stem cells (MSCs) in combination with a poly(vinylidene-trifluoroethylene)/barium titanate (PVDF-TrFE/BT) membrane on bone repair in osteoporotic rats. Osteoporosis was induced in female rats by bilateral removal of the ovaries (OVX) or sham surgery (SHAM), and the osteoporotic condition was characterized after 5 months by microtomographic and morphometric analyses. Calvarial defects were created in osteoporotic rats that immediately received the PVDF-TrFE/BT membrane. After 2 weeks, bone marrow-derived MSCs from healthy rats, characterized by the expression of surface markers using flow cytometry, or phosphate-buffered saline (PBS) (Control) were injected into the defects and bone formation was evaluated 4 weeks post-injection by microtomographic, morphometric, and histological analyses. A reduction in the amount of bone tissue in the femurs of OVX compared with SHAM rats confirmed the osteoporotic condition of the experimental model. More bone formation was observed when the defects were injected with MSCs compared to that with PBS. The modification that we are proposing in this study for the classical GBR approach where cells are locally injected after a membrane implantation may be a promising therapeutic strategy to increase bone formation under osteoporotic condition.

3.
Clin Oral Implants Res ; 28(8): 938-945, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27311365

RESUMO

OBJECTIVES: This study evaluated buccal bone crest remodeling, socket composition after healing, and dimensional ridge preservation after flapless tooth extraction procedures with or without a xenograft comparing histomorphometric and microcomputed tomographic (micro-CT) data. MATERIAL AND METHODS: The mandibular premolars of eight dogs were extracted without flaps. One socket on each side received a grafting material (test group), and the other remained only with a blood clot (control group). Twelve weeks after treatment, buccal bone crest, alveolar ridge dimensions, and composition were analyzed by histomorphometry and micro-CT. RESULTS: Two- and three-dimensional evaluations showed better results for the grafted group when compared to the non-grafted group. CONCLUSION: The flapless alveolar ridge preservation procedure with deproteinized bovine bone material enhanced buccal bone crest, alveolar ridge dimensions and bone formation when compared to sockets with the blood clot only, as observed by histomorphometric and micro-CT analysis.


Assuntos
Processo Alveolar/patologia , Remodelação Óssea , Extração Dentária/efeitos adversos , Processo Alveolar/diagnóstico por imagem , Processo Alveolar/cirurgia , Animais , Dente Pré-Molar/cirurgia , Substitutos Ósseos/uso terapêutico , Cães , Alvéolo Dental/diagnóstico por imagem , Alvéolo Dental/patologia , Microtomografia por Raio-X
4.
J. appl. oral sci ; 23(6): 623-628, Nov.-Dec. 2015. graf
Artigo em Inglês | LILACS | ID: lil-769815

RESUMO

ABSTRACT The ability of hemostatic agents to promote bone repair has been investigated using in vitro and in vivo models but, up to now, the results are inconclusive. Objective In this context, the aim of this study was to compare the potential of bone repair of collagen sponge with fibrin glue in a rat calvarial defect model. Material and Methods Defects of 5 mm in diameter were created in rat calvariae and treated with either collagen sponge or fibrin glue; untreated defects were used as control. At 4 and 8 weeks, histological analysis and micro-CT-based histomorphometry were carried out and data were compared by two-way ANOVA followed by Student-Newman-Keuls test when appropriated (p≤0.05). Results Three-dimensional reconstructions showed increased bone formation in defects treated with either collagen sponge or fibrin glue compared with untreated defects, which was confirmed by the histological analysis. Morphometric parameters indicated the progression of bone formation from 4 to 8 weeks. Additionally, fibrin glue displayed slightly higher bone formation rate when compared with collagen sponge. Conclusion Our results have shown the benefits of using collagen sponge and fibrin glue to promote new bone formation in rat calvarial bone defects, the latter being discreetly more advantageous.


Assuntos
Animais , Masculino , Regeneração Óssea/efeitos dos fármacos , Colágeno/farmacologia , Adesivo Tecidual de Fibrina/farmacologia , Hemostáticos/farmacologia , Osteogênese/efeitos dos fármacos , Modelos Animais de Doenças , Consolidação da Fratura/efeitos dos fármacos , Ratos Wistar , Reprodutibilidade dos Testes , Suínos , Crânio/efeitos dos fármacos , Crânio/lesões , Fatores de Tempo , Resultado do Tratamento , Microtomografia por Raio-X
5.
J Appl Oral Sci ; 23(6): 623-8, 2015 Nov-Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26814464

RESUMO

UNLABELLED: The ability of hemostatic agents to promote bone repair has been investigated using in vitro and in vivo models but, up to now, the results are inconclusive. Objective In this context, the aim of this study was to compare the potential of bone repair of collagen sponge with fibrin glue in a rat calvarial defect model. MATERIAL AND METHODS: Defects of 5 mm in diameter were created in rat calvariae and treated with either collagen sponge or fibrin glue; untreated defects were used as control. At 4 and 8 weeks, histological analysis and micro-CT-based histomorphometry were carried out and data were compared by two-way ANOVA followed by Student-Newman-Keuls test when appropriated (p≤0.05). RESULTS: Three-dimensional reconstructions showed increased bone formation in defects treated with either collagen sponge or fibrin glue compared with untreated defects, which was confirmed by the histological analysis. Morphometric parameters indicated the progression of bone formation from 4 to 8 weeks. Additionally, fibrin glue displayed slightly higher bone formation rate when compared with collagen sponge. CONCLUSION: Our results have shown the benefits of using collagen sponge and fibrin glue to promote new bone formation in rat calvarial bone defects, the latter being discreetly more advantageous.


Assuntos
Regeneração Óssea/efeitos dos fármacos , Colágeno/farmacologia , Adesivo Tecidual de Fibrina/farmacologia , Hemostáticos/farmacologia , Osteogênese/efeitos dos fármacos , Animais , Modelos Animais de Doenças , Consolidação da Fratura/efeitos dos fármacos , Masculino , Ratos Wistar , Reprodutibilidade dos Testes , Crânio/efeitos dos fármacos , Crânio/lesões , Suínos , Fatores de Tempo , Resultado do Tratamento , Microtomografia por Raio-X
6.
Clin Implant Dent Relat Res ; 17 Suppl 1: e202-20, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24283568

RESUMO

BACKGROUND: Finding the most effective method of minimizing the gap effect in alveolar crest remodeling constitutes a clinical challenge for immediate implant technique. PURPOSE: To evaluate the effectiveness of osseoconductive xenografts with different porosities in the crestal bone region, with and without guided bone regeneration, over immediate implant installation. MATERIALS AND METHODS: Five bone defects (6 mm in diameter/4 mm depth) were prepared on one side of the mandibles of twelve dogs. Implants of 3.3 × 10 mm were installed on the mesial side of each defect, providing a 2.7-mm distal gap. Defects were randomly filled with autogenous bone, coagulum, a deproteinized bovine bone mineral (DBBM) block, a DBBM sponge, or DBBM granules. The same procedures were performed on the opposite side after 8 weeks. Collagen membranes were used to cover the defects on half of the sides. The animals were sacrificed after 8 weeks. The outcomes were evaluated by histology, histomorphometric analysis, resonance frequency analysis, and micro-CT analysis. RESULTS: The histomorphometry showed the DBBM sponge to provide similar bone formation to autogenous bone at 8 weeks without a membrane. The coagulum rendered better bone formation at 16 weeks (membrane) (p < .05). The DBBM block exhibited the poorest results between treatments (8 and 16 weeks, with or without membrane). Micro-CT analysis revealed increasing bone surface values in sites with DBBM granules, followed by the DBBM sponge (8 weeks without membrane) and autogenous bone at 8 weeks with membrane (p < .05). Porosity analysis of the biomaterials showed the highest number, volume, and surface area of closed pores in DBBM granules. The DBBM block presented the highest volume of open pores, open porosity, and total porosity. CONCLUSIONS: The high-porosity block (DBBM block) failed to provide greater bone repair within the defect. Biomaterials with lower porosity (DBBM sponge and granules) showed similar or higher bone formation when compared with autogenous bone.


Assuntos
Perda do Osso Alveolar/prevenção & controle , Processo Alveolar/cirurgia , Remodelação Óssea , Transplante Ósseo/métodos , Implantação Dentária Endo-Óssea/métodos , Xenoenxertos , Perda do Osso Alveolar/diagnóstico por imagem , Perda do Osso Alveolar/patologia , Animais , Substitutos Ósseos/farmacologia , Colágeno/farmacologia , Implantes Dentários , Cães , Mandíbula , Membranas Artificiais , Porosidade , Cicatrização , Microtomografia por Raio-X
7.
Clin Oral Implants Res ; 23(12): 1340-51, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22093078

RESUMO

OBJECTIVE: Several implant surfaces are being developed, some in the nanoscale level. In this study, two different surfaces had their early healing properties compared in context of circumferential defects of various widths. MATERIAL AND METHODS: Six dogs had the mandibular premolars extracted. After 8 weeks, four implants were placed equicrestally in each side. One acted as control, while the others were inserted into sites with circumferential defects of 1.0, 1.5 and 2.0 mm wide and 5 mm deep. A nano-modified surface was used on one side and a micro-rough on the other. Bone markers were administered on the third day after implant placement and then after 1, 2, 4 weeks to investigate the bone formation dynamic through fluorescence analysis. Ground sections were prepared from 8-week healing biopsies and histomorphometry was performed. RESULTS: The fluorescence evaluation of the early healing showed numerically better results for the nano-modified group; however this trend was not followed by the histomorphometric evaluation. A non-significant numerical superiority of the micro-rough group was observed in terms of vertical bone apposition, defect bone fill, bone-to-implant contact and bone density. In the intra-group analysis, the wider defects showed the worse results while the control sites showed the best results for the different parameters, but without statistical relevance. CONCLUSION: Both surfaces may lead to complete fill of circumferential defects, but the gap width has to be considered as a challenge. The nano-scale modification was beneficial in the early stages of bone healing, but the micro-rough surface showed numerical better outcomes at the 8-week final period.


Assuntos
Implantação Dentária Endo-Óssea/métodos , Implantes Dentários , Mandíbula/cirurgia , Cicatrização , Animais , Dente Pré-Molar/cirurgia , Densidade Óssea , Cães , Masculino , Microscopia de Fluorescência , Propriedades de Superfície , Retalhos Cirúrgicos , Gravação em Vídeo
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