RESUMO
Nowadays the reconstruction of craniofacial defects can be performed with different kinds of materials, which include the bone and the so-called biomaterials, which have the advantage of not needing a surgical site donor. Among these materials, great attention is given to polymers. In this large group, current attention is focused on the castor oil polymer, since this polymer is biocompatible, low cost, and has adequate strength for reconstruction of the craniomaxillofacial complex. This study aims to report the use of a prosthetic castor oil polymer for reconstruction of extensive defect, caused by a trauma, in the temporoparietal region.
RESUMO
OBJECTIVE: The purpose of this study was to evaluate the sealing ability of castor oil polymer (COP), mineral trioxide aggregate (MTA) and glass ionomer cement (GIC) as root-end filling materials. Forty-five single-rooted human teeth were cleaned and prepared using a step-back technique. The apical third of each root was resected perpendicularly to the long axis direction. All teeth were obturated with gutta-percha and an endodontic sealer. After, a root-end cavity with 1.25-mm depth was prepared using a diamond bur. The specimens were randomly divided into three experimental groups (n=15), according to the root-end filling material used: G1) COP; G2) MTA; G3) GIC. The external surfaces of the specimens were covered with epoxy adhesive, except the root-end filling. The teeth were immersed in rhodamine B dye for 24 hours. Then, the roots were sectioned longitudinally and the linear dye penetration at the dentin/material interface was determined using a stereomicroscope. ANOVA and Tukey's tests were used to compare the three groups. The G1 group (COP) presented smaller dye penetration, statistically different than the G2 (MTA) and G3 (GIC) groups (p<0.05). No statistically significant difference in microleakage was observed between G2 and G3 groups (p>0.05). The results of this study indicate that the COP presented efficient sealing ability when used as a root-end filling material showing results significantly better than MTA and GIC.
Assuntos
Humanos , Biopolímeros , Óleo de Rícino , Infiltração Dentária/prevenção & controle , Obturação Retrógrada , Materiais Restauradores do Canal Radicular , Compostos de Alumínio , Compostos de Cálcio , Adaptação Marginal Dentária , Combinação de Medicamentos , Cimentos de Ionômeros de Vidro , Óxidos , SilicatosRESUMO
Avaliou-se o comportamento mecânico do polímero de mamona, tendo por variáveis o tempo de produção e a presença de catalisador, e utilizando como padrão comparativo o cimento ósseo (polimetilmetacrilato). Foram estabelecidos três grupos experimentais, de acordo com o tipo de corpo de prova (cilindro ou barra) e polímero utilizado, que foram posteriormente subdivididos em subgrupos conforme o tempo após produção, ou seja, 24, 48 e 72 horas. O ensaio de compressão analisou a carga máxima e a tensão e o ensaio de dobramento estudou o módulo de dobramento e a resistência. Estatisticamente não houve diferenças nos valores de resistência à compressão ou ao dobramento às 24, 48 e 72 horas após a produção do polimetilmetacrilato e da poliuretana, com ou sem catalisador. A poliuretana com catalisador foi a mais resistente nos ensaios de compressão, apresentando módulo de dobramento semelhante ao do polimetilmetacrilato e resistência ao dobramento superior à da poliuretana sem catalisador. Conclui-se que: o tempo não alterou as propriedades mecânicas dos compósitos avaliados; o catalisador melhorou o desempenho mecânico da poliuretana de mamona; na resistência mecânica à compressão, a poliuretana com catalisador suportou mais carga que o polimetilmetacrilato.
The mechanical properties of castor oil-based polyurethane was evaluated considering post-production time and the presence of a catalyst as variables and using bone cement (polymethylmetacrylate) as a comparative pattern. According to proof body type (cylinders or bars) and the used polymer, three experimental groups were established. Such groups were later subdivided according to post-production time, namely, 24, 48, and 72 hours. A compression assay analyzed maximum load and tension, and a folding assay evaluated the folding module and resistance. There were no statistical differences in the values for resistance to compression or folding at 24, 48, and 72 hours after the production of polymethylmetacrylate and polyurethane with or without a catalyst. Castor oil-based polyurethane with a catalyst showed to be the most resistant during the compression assays as its folding module was similar to that of polymethylmetacrylate, and its folding resistance was higher than that of polyurethane without a catalyst. In conclusion, time did not change the mechanical properties of the evaluated composites; the catalyst improved the mechanical performance of castor oil-based polyurethane; castor oil-based polyurethane with a catalyst supported more load during the assay for mechanical resistance to compression than did polymethylmetacrylate.
Assuntos
Materiais Biocompatíveis/química , Poliuretanos/uso terapêutico , Resinas Acrílicas/uso terapêutico , Ricinus/química , Substitutos Ósseos/uso terapêuticoRESUMO
PURPOSE: Comparative morphologic study of utilization of castor oil polymer in dogs joints, as an alternative technique to autogenous graft, in surgical correction of medial patella luxation. METHODS:Twelve adult dogs, of both sexes, were randomly allocated to two different groups of six animals each. Group I (biopolymer) consisted of the deepening of the right femoral troclea, with the implantation of the biopolymer prothesis, and compared to group II (control) which consisted of the conventional trocleoplastia technique with wedged cut of the left femoral troclea. The dogs were sacrified after 30 or 90 days and the anathomic peaces were analyzed macro and microscopically. Qui square and Wilcoxon tests were used for the statistic analyses of the results, considering probability of 5 percent. RESULTS: It was not observed bony integration on the castor oil polymer group. There was resorption of the graft along experimental period and absence of inflammatory cells in the studied periods. CONCLUSION: Castor oil polymer assisted cicatrisation process, was biocompatible without inflammation, and it can be used in joints as an alternative for bony filling.(AU)
OBJETIVO: Estudo morfológico do implante da prótese de polímero de mamona em articulações de cães, como técnica alternativa ao enxerto ósseo autógeno na correção cirúrgica da luxação medial de patela. MÉTODOS: Doze cães adultos, de ambos os sexos, foram distribuídos aleatoriamente em dois grupos de 6 animais. No grupo I (poliuretano) foi feito o aprofundamento da tróclea femoral direita com prótese de polímero de mamona, que foi comparado com o grupo II (controle) sendo feita a trocleoplastia por ressecção em cunha da tróclea femoral esquerda. Os animais foram sacrificados após 30 e 90 dias e as peças anatômicas foram avaliadas macro e microscopicamente. O teste do quiquadrado e o teste não-paramétrico de Wilcoxon foram utilizados para a análise estatística dos resultados. Fixou-se em 5 por cento, o nível de rejeição da hipótese de nulidade. RESULTADOS: Não foi observada interação óssea (osteointegração) no grupo polímero de mamona. Houve reabsorção do enxerto ao longo do período experimental e ausência de células inflamatórias nos períodos analisados. CONCLUSÃO: O polímero de mamona auxiliou no processo cicatricial, foi biocompatível sem presença de inflamação, podendo ser usado em articulações como uma alternativa para o preenchimento ósseo.(AU)