Non-conventional cement-based composites reinforced with vegetable fibers: a review of strategies to improve durability

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

Supercritical carbonation treatment on extruded fibre-cement reinforced with vegetable fibres

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

Effect of the particle size of maize, rice, and sorghum in extruded diets for dogs on starch gelatinization, digestibility, and the fecal concentration of fermentation products

The influence of rice, maize, and sorghum raw material particle size in extruded dry dog food on the digestibility of nutrients and energy and the fecal concentration of fermentation products was investigated. Three diets with similar nutrient compositions were formulated, each with 1 starch source. Before incorporation into diets, the cereals were ground into 3 different particle sizes (approximately 300, 450, and 600 mu m); therefore, a total of 9 diets were in a 3 x 3 factorial arrangement (3 cereals and 3 particle sizes). Fifty-four beagle dogs (12.0 +/- 0.1 kg BW) were randomly assigned to the diets, with 6 dogs per diet. The digestibility was measured with the chromium oxide method. The data were evaluated with ANOVA considering the carbohydrate source, grinding effect, and interactions. The means were compared with the Tukey test and polynomial contrasts (P < 0.05). With the same grinding procedure, rice was reduced to smaller particles than other cereals. The cereal mean geometric diameter (MGD) was directly related to starch gelatini-zation (SG) during extrusion. For rice diets, the MGD and SG did not change nutrient digestibility (P > 0.05); only GE digestibility was reduced at the largest MGD (P < 0.01). For maize and sorghum diets, the total tract apparent nutrient digestibility was reduced for foods with greater MGD and less SG (P < 0.01). A linear reduction in nutrient digestibility according to cereal particle size was observed for sorghum (r(2) < 0.72; P < 0.01). Higher concentrations of fecal total shortchain fatty acids (SCFA) were observed for sorghum diets (P < 0.05) than for other diets. The rice diets led to the production of feces with less lactate (P < 0.05). The increase in raw material MGD did not influence fecal SCFA for rice diets, but for the dogs fed maize and sorghum foods, an increase in propionate and butyrate concentrations were observed as MGD increased (P < 0.05). In conclusion, for dogs fed different particle sizes of the cereal starches in the extruded diets, the digestibility and fecal characteristics were affected, and this effect was ingredient dependent.

Effect of crown-to-implant ratio on peri-implant stress: a finite element analysis

The aim of this study was to evaluate stress distribution in the fixation screws and bone tissue around implants in single-implant supported prostheses with crowns of different heights (10,12.5, 15 mm crown-to-implant ratio 1:1, 1.25:1, 1.5:1, respectively). It was designed using three 3-Dmodels. Each model was developed with a mandibular segment of bone block including an internal hexagon implant supporting a screw-retained, single metalceramic crown. The crown height was set at 10, 12.5, and 15 mm with crown-to-implant ratio of 1:1, 1.25:1, 1.5:1, respectively. The applied forces were 200 N (axial) and 100 N (oblique). The increase of crown height showed differences with the oblique load in some situations. By von Mises'criterion, a high stress area was concentrated at the implant/fixation screw and abutment/implant interfaces at crown-to-implant ratio of 1:1, 1.25:1, 1.5:1, respectively. Using the maxiinum principal criteria, the buccal regions showed higher traction stress intensity, whereas the distal regions showed the largest compressive stress in all models. The increase of C/I ratio must be carefully evaluated by the dentist since the increase of this C/I ratio is proportional to the increase of average stress for both screw fixation (C/I 1:1 to 1:1.25 ratio = 30.1% and C/I 1:1 to 1 :1.5 ratio = 46.3%) and bone tissue (C/I 1:1 to 1:1.25 ratio = 30% and C/I 1:1 to 1:1.5 ratio = 51.5%). (C) 2014 Elsevier B.V. All rights reserved.

Bladder augmentation in rabbits with anionic collagen membrane, with or without urotelial preservation. Cistometric and hystologic evaluation

The use of bowel segments to perform bladder augmentation is associated with several metabolic and surgical complications. A great variety of synthetic materials, biodegradable or not, have been tested. Collagen-based biomaterials have shown effectiveness for the regeneration and obtainment of a functional bladder. Assess the functional and histological response of the rabbit bladder to anionic collagen membrane (ACM), either when it is anastomosed to the bladder or it is placed onto bladder after vesicomyectomy. In 15 male rabbit a partial cystectomy was performed. After 4 weeks they were divided in 3 groups. Group 1 (G1) - bladder augmentation with ACM. Group 2 (G2) ACM is placed onto bladder after vesicomyectomy. Group 3 (G3) control group. Maximal bladder capacity (MBC) and weight were assessed with 4 (M1), 8 (M2) and 12 (M3) weeks after partial cystectomy. In M3 was performed the sacrifice and extraction of the bladder and kidneys for anatomopathologic study. There were neither bladder stones, nor implant extrusion in M3. There was a significant increase in MBC in G1 and G2 (p<0.05), but no statistical differences in G3 (p=0.35). There is no significant difference comparing G1 and G2. In M3, both groups have shown a bigger MBC than G3 (p<0.05). The microscopic assessment showed an inflammatory reaction in the bladder augmented, with urothelium preserved. The ACM was effective for the increase of MBC. The bladders with preservation of the urothelium have shown an extensive inflammatory process.

A 3-D finite element study of the influence of crown-implant ratio on stress distribution

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

Effect of the parafunctional occlusal loading and crown height on stress distribution

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

Regeneração óssea vertical usando barreira não-porosa de politetrafluoretileno em implantes osteointegrados inseridos parcialmente na tíbia de coelhos

The purpose of this study was to evaluate the possibility to obtaining guided bone regeneration utilizing a nonporous PTFE barrier in the osseointegrated implants, protruding from the bone level of the rabbit tíbia. The histologic characteristics of the interface between titanium implants, one group titanium-plasma coated, another group with acid-treated surfaces and the regenerated bone were also studied Twenty Screw-Vent implants were placed in tibias of five rabbits, two at the right side and two at the left side, protruding 3 mm from the bone level, to create a horizontal bone defect. ln the experimental side, the implants and adjacent bone were protected with a nonporous PTFE barrier. Histologic analysis after three months showed that all implants were in direct contact with the bane. Histologic measurements showed an average gain in bone height of the 2.15 and 2.42 mm for the barrier group and 1.95 and 0.43 mm for the control defects, in the titanium plasma-spray and acid-treated implant surfaces, respectively. The results suggest that the placement of implants protruding 3 mm from crestal bone defects may result in vertical bone augmentation and the regenerated bone is able to osseointegrate implants. lt seems to be critical the use of the PTFE barrier when acid-treated surface implants are inserted

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.

Caracterização físico-mecânica de painéis de partículas de bambu com adição de casca de café

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Características químico-mineralógicas e cerâmicas da matéria-prima utilizada pelo polo cerâmico de Rio Verde de Mato Grosso, MG

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Uso do amido resistente na promoção da saúde intestinal de cães idosos: formação de produtos de fermentação e características histológicas da mucosa intestinal

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Fibra para cães: efeitos sobre o processo de extrusão, digestibilidade, fermentação microbiana, tempo de retenção intestinal e palatabilidade de rações para cães

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Multidisciplinary approach for crown-root fracture treatment after trauma: case report

The development of an accurate diagnosis and appropriate treatment plan can be a complex task, especially in cases of dentoalveolar trauma. The authors present a case report of crown-root fracture caused by trauma and highlight the importance of a multidisciplinary approach for the treatment. An eighteen year-old boy had a bicycle accident resulting in dental trauma. The upper right first molar showed a complicated crownroot fracture and the lower left second pre-molar showed an uncomplicated crown-root fracture. Endodontic treatment, controlled tooth extrusion, periodontal surgery for recovery of biological width, and porcelain crown and onlay restorations were performed. Esthetic and functional results were achieved. At the two-year follow-up it was observed that the tooth/onlay interface of the upper right first molar was stained and the onlay of the left lower second pre-molar was fractured. Therefore, the interface stained was repaired and a porcelain crown was made for the lower second premolar. The clinical case presented herein leads to the conclusion that a multidisciplinary treatment plan is extremely important for a proper resolution in cases of dentoalveolar trauma.

Reconstrução imediata de fenestração peri-implantar com enxerto autógeno em bloco de ramo mandibular

Alveolar wall fenestrations are common during implant placement. The aim of this paper is to report a case where a peri-implant bone fenestration was reconstructed immediately after implant placement by an autogenous mandibular bone block. A male patient was referred to the Department of Surgical and Integrated Clinics to substitute his Kennedy´s Class IV removable partial denture for an implantsupported fixed prosthesis. A peri-implant bone fenestration at the buccal wall was seen at the region of 12, being reconstructed by a mandibular bone block secured by a bicortical screw. Six months later the surgical procedures, an implant-supported complete fixed partial prosthesis was developed. The autogenous bone block harvested from the mandibular ramus was a safe alternative to reconstruct the peri-implant bone defect such as fenestration types.