Evaluation of sodium diclofenac release using natural rubber latex as carrier

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Biological compatibility of some types of endodontic calcium hydroxide and glass ionomer cements

The purpose of this work was to evaluate the biological compatibility of the Sealapex, Apexit, Sealer 26 and Ketac Endo endodontic cements. Polyethylene tubes containing these cements were implanted in the subcutaneous tissue of 40 (forty) rats. The animals were sacrificed after 14 and 90 days. A descriptive analysis of the reactions found in the connective tissue by contact with the cements was performed. The magnitude of inflammatory infiltrate, the presence and predominance of cell types and their distribution as to the filling material and reparative phenomena, such as fibroblastic and angioblastic proliferation and formation of fibrous capsules, were subjectively measured. After 90 days, all cements presented statistically significant reduction of the inflammatory reaction, presence of a fibrous tissue capsule in contact with the opening of the tubes containing the filling materials, and reduction of fibroblastic proliferation. Angioblastic proliferation decreased only for the Sealer 26 and Ketac Endo groups. All cements tested were either partially or totally phagocyted, and the mildest inflammatory response was found for the Sealer 26 group at both evaluation periods.

An esthetics rehabilitation with computer-aided design/ computer-aided manufacturing technology

This paper describes a case of a rehabilitation involving Computer Aided Design/Computer Aided Manufacturing (CAD-CAM) system in implant supported and dental supported prostheses using zirconia as framework. The CAD-CAM technology has developed considerably over last few years, becoming a reality in dental practice. Among the widely used systems are the systems based on zirconia which demonstrate important physical and mechanical properties of high strength, adequate fracture toughness, biocompatibility and esthetics, and are indicated for unitary prosthetic restorations and posterior and anterior framework. All the modeling was performed by using CAD-CAM system and prostheses were cemented using resin cement best suited for each situation. The rehabilitation of the maxillary arch using zirconia framework demonstrated satisfactory esthetic and functional results after a 12-month control and revealed no biological and technical complications. This article shows the important of use technology CAD/CAM in the manufacture of dental prosthesis and implant-supported.

Acrylic resin cytotoxicity for denture base - Literature review

Acrylic resin is a widely used material in clinical practice, and a satisfactory biocompatibility is essential. When the resin polymerization reaction is incomplete, residual monomers are released into the oral cavity. The aim of this study was to evaluate, through a literature review, the cytotoxicity caused by the denture base acrylic resin used, and its components. The selection of published studies was performed on the Pubmed database from January 2008 to July 2013. The keywords used were: cytotoxicity and acrylic resins, cytotoxicity and denture base resins and cytotoxicity and oral prosthesis. Inclusion criteria were: in vitro studies and literature reviews published in English that evaluated the acrylic resin cytotoxicity for denture base and its components. Studies with no reference to the search strategy were excluded. A total of 182 articles were found. Among these, only 13 were included for writing this review. The MTT test is the most common test used to evaluate acrylic resin cytotoxicity. Auto-polymerized resin is more cytotoxic than heat-polymerized resin because of its higher quantity of residual monomers which cause cell and tissue changes in the oral mucosa. However, more studies are necessary for the development of biocompatible materials.

Osteoblast response to porous titanium and biomimetic surface: In vitro analysis

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Incorporation of Ca, P, and Si on bioactive coatings produced by plasma electrolytic oxidation: The role of electrolyte concentration and treatment duration

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Titanium-35niobium alloy as a potential material for biomedical implants: in vitro study

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação da biocompatibilidade de dois adesivos dentinários pelo estudo das reações teciduais em conjuntivo de ratos

The biocompatibility of two dentin adhesives (Scotchbond MultiPurpose- 3M and Optibond Multi-Use - Kerr) was evaluated in rats subcutaneous connective tissue implants. Polyethylene tubes filled with the adhesives were surgically implanted into the dorsal subcutaneous tissues of rats. The tubes were left implanted for periods of 14, 30, 60 and 84 days, following wich the animais were killed and the implants, together with the surrounding tissue, were excised. The specimens were then fixed in 10 per cent formalin, sectioned serially and stained with hematoxylin and eosin and then, examined by light microscopy. After 14 and 30 days the tubes were surrounded by a mild to moderate inflammatory infiltration. After 60 and 84 days microscopic examination revealed the formation of a connective tissue capsule around each tube. The microscopic examination of the biopsy specimens allowed to conclude that: a) both dentin adhesives are considered biologically acceptable when placed in contact with rats subcutaneous connective tissue; b) in the observation period of 30 days there were moderate tissue reaction to the Optibond Multi-Use -light cure- (Kerr); c) after 60 and 84 days the use of both dentine adhesives did not interfere in the healing of the surrounding connective tissue

Análise da biocompatibilidade de cones de biovidro e biovitrocerâmico (Biosilicato®) em cavidade eviscerada de coelho

OBJETIVO: Avaliar experimentalmente a biocompatibilidade de cones de biovidro e biovitrocerâmico em cavidades evisceradas de coelhos. MÉTODOS: Foram utilizados 45 coelhos albinos submetidos à cirurgia de evisceração do olho direito, seguida da inclusão de cones de biovidro e dois tipos de biovitrocerâmicos (chamados de FI e FII) na cavidade escleral. Os animais foram sacrificados em três momentos (7, 90 e 180 dias). Os parâmetros avaliados foram: peso, exame clínico diário, exames bioquímicos, avaliação histológica, exame morfométrico. RESULTADOS: Os animais mantiveram-se saudáveis durante o experimento, não tendo ocorrido extrusão do implante em nenhum animal. O exame morfológico mostrou que houve a formação de pseudocápsula ao redor dos cones, com superioridade dos cones de biovidro e biovitrocerâmico FI, os quais apresentaram menor reação inflamatória e menor formação da pseudocápsula ao redor dos cones que os demais. A reação inflamatória foi mais intensa após 7 dias da colocação dos cones, diminuindo em direção aos 180 dias, sendo menos intensa nos coelhos que receberam cones de biovidro. CONCLUSÃO: Os cones de biovidro e biovitrocerâmico FI e FII podem ser úteis para a reparação da cavidade anoftálmica, com melhor resposta quando se usa cones de biovidro e de biovitrocerâmico FI.

Biomateriais aplicados à implantodontia

There are many ways in which materials and tissues can be brought into contact such that this co-existence may be compromised, and the search for biomaterials that are able to provide for the best performance in devices has been based upon the understanding of all interactions within biocompatibility phenomena. In this paper, the authors related the biomaterials properties applied in Implantology and their clinical indications.

Regeneração óssea guiada com o uso de matriz óssea bovina desmineralizada em defeitos ósseos experimentais em cães

Background: The principles of tissue regeneration to repair alveolar bone defects are based on the fabrication of a biologic barrier with different biomaterials. Therefore, the present study aimed to investigate the guided bone regeneration (GBR) by using membrane of demineralized bovine bone matrix (DBBM) on experimental defects in tibia of dogs. Methods: Four dogs were used and after anesthesia, shaving and antisepsis, two standardized bone defects were created on the right tibia of each animal with trephine drill. In the Control Group, the defects were filled with blood coagulum, while in the Treated Group, a membrane of DBBM was used to cover the defects. After 90 days, animals were sacrificed. Results: In the Treated Group, 67.4% of new bone formation was observed and, in the Control Group, 32.6% of the bone tissue reabsorbed when compared with initial bone volume. The membrane remained intact and no inflammatory tissue was observed on membrane/ bone interface. Conclusion: It was concluded that the use of DBBM is an osteoconductive material, presents biocompatibility and may be promise option to repair bone defects.

Adesivo tecidual de fibrina e sua aplicação na implantodontia

The purpose of this literature review was to evaluate the use of fibrin tissue adhesive in implant dentistry. Materials and Methods: A literature search of Medline-PubMed for articles published, describing the use of fibrin tissue adhesive in implant dentistry was performed and articles were critically reviewed. Results: The literature review reveals clinical trials and experimental studies with regard to the use of fibrin tissue adhesive in implant dentistry. This material consists of 2 components: highly purified, freeze-dried human fibrinogen with factor XIII and a starter solution containing human thrombin. Clotting factor XIII is admitted for reinforcement of the fibrin network. The components are reconstituted before use and when mixed form a clot by mimicking the terminal phase of the physiological clotting cascade. Several studies showed that fibrin tissue adhesive is fully absorbed by macrophages within 2 weeks of application. Adhesive fibrin tissue may be used for to prevent bone loss, to create contour in the periimplant soft tissue and osseous tissue, to sculpt emergence profile for prosthetic components and to mimic tissue architecture. In the last years fibrin tissue adhesive also find use as material for the controlled delivery of drugs and biologics. Conclusions: The fibrin tissue adhesive presents good properties such as biocompatibility, hemostatic properties and ability to break down like the physiologic clot. This material, alone or associated with other materials, can be used with the implants immediately after extraction. In this condition it brings the necessary anchoring and efficient maintenance of osseous/mucosal contour, which it is important for the clinical success.

Avaliação da biocompatibilidade de implantes de silicone gel em subcutâneo de ratos: estudo histomorfométrico

Objective: Histomorphometric study to evaluate the biological tissue compatibility of silicone implants suitable for plastic surgery. Methods: Thirty Wistar white rats received subcutaneous implants ande the revestiment of silicone gel Silimed, and randomized into six groups of five animals each, according to the type of implanted material and the time of sacrifice. Eight areas of 60.11 mm2 corresponding to the obtained surgical pieces were analyzed, counting mesenchymal cells, eosinophils, and foreign body giant cells, observing an acceptable biocompatibility in all implants, for subsequent statistical analysis by Tukey test. Results: Silicone gel showed inflammation slightly greater than for other groups, with tissue reactions varying from light to moderate, whose result was the formation of a fibrous capsule around the material, recognized by the organism as a foreign body. Conclusion: In general, it is possible to affirm that silicone gel had acceptable levels of biocompatibility, confirmed the rare presence of foreign body giant cells, and when of the rupture, formed a fibrous capsule around the material, separating the material of the organism.

Avaliação da incorporação de enxerto osseo homogeno fresco congelado em humanos: análise histologica e imuno-histoquímica

Allogeneic, fresh-frozen bone has been used in order to replace bone autografts. However, its osteoinduction and osteoconduction properties are not well-defined in the scientific literature. This work aimed to evaluate samples of homogenous bone grafts in humans by qualitative histological and immunohistochemical analysis. For this, ten pre-selected patients underwent surgical augmentation of bone defects. The homogenous fresh frozen block bone graft was stabilized and fixed by bicortical screws. After six months, the reopening procedure was performed for installation of osseointegrated implants. At this time surgical bone graft samples were removed by means of drill trephine. The samples were fixed in 10% formalin, processed with decalcified paraffin, and stained with hematoxylin and eosin. Immunohistochemistry was performed for the expression of Caspase 3 enzyme. The slides were brought to light microscopy for qualitative histology and immunohistochemistry. The results showed non-vital bone tissue, with few areas of deposition of new bone formation on the amorphous matrix, presence of chronic inflammatory infiltrate with areas of osteomyelitis, and expressive immunolabeling of Caspase 3. Given the methods employed and the results it was concluded that the allograft fresh-frozen block is not incorporated into the recipient bed after a healing period of six months.

Reabilitação de maxila atrófica com tecido ósseo homógeno e prótese fixa implantossuportada

The techniques of bone reconstruction for atrophic maxillae have been improved in order to promote bone tissue growth in both height and thickness. The grafts performed with use of autogenous bone is considered the gold standard by most researchers, for demonstrating osteogenic capacity and not to promote antigenic response. However, this type of grafting is not possible to get bone tissue in large quantity for extensive renovations. In recent years, alternatives have been researched to overcome the limitations of autogenous bone. Several alternatives have been investigated to supply the disadvantages of autogenous bone grafts. In such studies, allogeneic bone grafts which are obtained from individuals with different genetic load, but from the same species have been extensively used. They can be indicated in cases of arthrosplasty, surgical knee reconstruction, and large bone defects as well as in oral and maxillofacial reconstruction. Besides showing great applicability and biocompatibility, this type of bone is available in unlimited quantities. To rehabilitate atrophic maxillae an option that has been performed with high success rate is the reconstruction with bone graft followed by osseointegrated dental implants to rehabilitate the patient aesthetics and functionally. This paper aims to show the feasibility of allogenic bone as material for reconstruction of atrophic maxilla, and subsequent rehabilitation with metal ceramic fixed prosthesis implant and dental restoration with accompanying three years through literature review and clinical case report.