Histomorphometric analysis of the repair process of autogenous bone grafts fixed at rat calvaria with cyanoacrylate

OBJECTIVE: The purpose of this study was to perform histological and histometric analyses of the repair process of autogenous bone grafts fixed at rat calvaria with ethyl-cyanoacrylate adhesive. MATERIAL AND METHODS: Thirty-two rats were divided into two groups (n=16), Group I - Control and Group II - Adhesive. Osteotomies were made at the right parietal bone for graft obtainment using a 4-mm-diameter trephine drill. Then, the bone segments were fixed with the adhesive in the parietal region of the opposite side to the donor site. After 10 and 30 days, 8 animals of each group were euthanized and the calvarias were laboratorially processed for obtaining hematoxylin and eosin-stained slides for histological and histometric analyses. RESULTS: An intense inflammatory reaction was observed at the 10-day period. At 30 days, this reaction was less intense, despite the presence of adhesive at the recipient-site/graft interface. Graft incorporation to the recipient site was observed only at the control group, which maintained the highest graft size at 10 and 30 days. CONCLUSIONS: Although the fragment was stable, the presence of adhesive in Group II did not allow graft incorporation to the recipient site, determining a localized, discrete and persistent inflammatory reaction.

Análise do processo de reparo ósseo de cavidades cirúrgicas preenchidas com osso autógeno e recobertas por membrana de matriz óssea homógena e de politetrafluoretileno em ratos / Process of bone repair of surgical cavities filled out with autogenous bone and covered by a membrane of homogenous bone matrix and polytetrafluoroethylene in rats

Proposição: O objetivo deste trabalho foi avaliar, qualitativa e quantitativamente, o comportamento da membrana de matriz óssea homógena desmineralizada e conservada em glicerinae e membrana de Ptfe no processo de reparo ósseo de cavidades cirúrgicas preenchidas com osso autógeno realizadas em tíbias de ratos Material e Métodos: Foram utilizados 60 ratos (Rattus norvegicus albinus, Wistar) machos, com aproximadamente 250 gramas divididos em três grupos: o grupo I (Controle-sem membrana), grupo II (membrana homógena) e grupo III (membrana de ptfe). Após tricotomia, anestesia e antissepsia foi realizada uma incisão longitudinal nas regiões antero-laterais de cada tibia. Após exposição das tíbias, duas cavidades cirúrgicas de 2mm de diâmetro foram preparadas com trefina em baixa-rotação refrigerada, uma no membro posterior esquerdo e outra no membro posterior direito, sendo a primeira preenchida com o osso autógeno particulado coletado durante a realização das duas cavidades e recobertas pelas membranas utilizadas no estudo. Aos 10 e 60 dias pós-operatórios os animais foram eutanaziados e as peças obtidas foram processadas laboratorialmente para a realização de cortes semi-seriados com seis micrômetros de espessura e corados pela hematoxilina e eosina para análise histomorfométrica. Resultados e Conclusão: A membrana homógena mostrou-se biocompatível e cumpriu sua função e em termos de área óssea neoformada as membranas obtiveram desempenho semelhantes.

Purpose: The aim of this study was to evaluate the behavior of membrane of a demineralized homogenous bone matrix and preserved in glycerin and the Ptfe membrane in the process of bony repair of surgical cavities filled out with autogenous bone accomplished in tibias rats. Materials and Methods: Sixty male rats weighing approximately 250 g were selected and assigned to two groups, as follows. Group I (without membrane), Group II (homogenous membrane) and Group III ( Ptfe membrane). After anesthesia, shaving and antisepsis, a longitudinal incision was made in the anterolateral areas of each tibia. After exhibition of the tibias, two surgical cavities of 2mm of diameter were prepared with trefina in refrigerated low-rotation, one in the left posterior member, other in the right subsequent member, being the first filled out with particulate autogenous bone collected during the accomplishment of the two cavities and covered with the membrane. Ten and sixty days postoperatively, the animals were euthanized and the anatomical pieces were submitted to routine laboratorial processing and serially sectioned to obtain 6-μm-thick sections, which were stained by hematoxylin and eosin for histomorphometric analysis. Results and Conclusions: The homogenous membrane proved to be biocompatible and fulfilled its function and in terms of bone area formation membranes had similar performance.

Repair process of surgical defects filled with autogenous bone grafts in tibiae of diabetic rats

From a biological standpoint, the best material for reconstruction of bone defects is the autogenous bone graft. However, as tissue healing is affected under diabetic conditions, major changes might take place in the revascularization, incorporation, replacement and remodeling phases of the grafted area. The purpose of this study was to assess the bone healing process in surgical wounds prepared in tibiae of diabetic rats and filled with autogenous bone. Forty male rats (Rattus norvegicus albinus, Wistar) were randomly assigned to receive an endovenous injection (penile vein) of either citrate buffer solution (Group 1 - control; n=20) or streptozotocin dissolved in citrate buffer solution (35 mg/kg) to induce diabetes (Group 2 - diabetic; n=20). After determination of glycemia, the animals were anesthetized and the anterolateral regions of the tibiae of both limbs were shaved, antisepsis was performed and longitudinal incisions were made in each limb. The tibiae were exposed and two 2mm-diameter surgical cavities were prepared: one in the right limb, filled with particulate autogenous bone and the other in the left limb, filled with blood clot. The animals were euthanized at 10 and 30 postoperative days. The anatomic pieces were obtained, submitted to laboratory processing and sections were stained by hematoxylin and eosin and Masson's Trichrome for histomorphologic and histometric analyses. In both groups, the wounds filled with autogenous bone graft showed better results than those filled with blood clot. The control group showed higher new bone formation in wounds filled with autogenous bone graft at 30 days than the diabetic group, but without statistical significance. It may be concluded that, in general, the new bone formation occurred with autogenous graft was quantitatively similar between control and diabetic groups and qualitatively better in the control group.

Carcinoma espinocelular de língua e assoalho de boca em paciente jovem / Squamous cell carcinoma of tongue and floor of mouth in a young patient

Os autores apresentam um caso clínico de carcinoma espinocelular em paciente leucoderma do sexo feminino com 22 anos de idade, fumante há 4 anos, com lesão ulcerada crateriforme em borda lateral de língua e assoalho bucal esquerdo. O exame clínico evidenciou atraso do diagnóstico e erros terapêuticos de vários cirurgiões-dentistas. O objetivo dos autores é abordar aspectos clínico-patológicos, possíveis tratamentos e prognóstico dessa lesão, enfatizando a importância de um melhor preparo do CD em relação aos conhecimentos de câncer bucal e à conduta diante de uma lesão que sugere malignidade.