Adhesivos de cianoacrilato en cirugía oral y maxilofacial / Cyanoacrylate adhesives in oral and maxillofacial surgery

RESUMEN: Los adhesivos de cianoacrilatos (ACA) son materiales sintéticos con propiedades adhesivas. Al ser aplicados en los tejidos polimerizan uniéndose con el tejido subyacente. Desde la década de los 70' se han explorado sus aplicaciones quirúrgicas para el cierre de heridas y fístulas, control de sangrado y fijación de injertos, entre otros, siendo su uso como alternativa para el cierre de heridas en piel y mucosas uno de los más estudiados. Los ACA presentan un limitado grado de absorción, sin evidencia de efectos tóxicos sistémicos. Tienen la ventaja de ser aplicados de forma rápida, indolora, con efecto antibacteriano y hemostático según los reportes de la literatura, pero presentan una reducida fuerza de tensión. El objetivo de esta revisión de la literatura es describir los usos y aplicaciones de los ACA, con enfoque en la cirugía oral y maxilofacial, evaluando de forma crítica sus aplicaciones.

ABSTRACT: The cyanoacrylate adhesives (ACA) are synthetic materials with adhesive properties. When is applied in tissues, it polymerizes and bonds with the underlying tissue. Since the 70s' have been explored their surgical applications for closing wounds, fistulas, bleeding control, and graft fixation, among others. Its use as an alternative for closing wounds in skin and mucous is one of the most studied. The ACA have a limited absorption degree, with no evidence of systemic toxic effects. They have the advantage of being applied quickly, painlessly, with antibacterial effect and hemostatic according to the report of literature, but with reduced tensile strength. The objective of this literature review is to describe the use and applications of ACA, with focus on oral and maxillofacial surgery, with a critically evaluation of their applications.

Evaluación de la histotoxicidad del 2-octyl-cyanoacrilato en el cerebro del conejo / Histotoxicity evaluation of 2-octyl-cyanoacrylate on the rabbit's brain

The aim of the present study was to evaluate the effect of the 2-octyl-cyanoacrylate, on a rabbit's brain. The study was undertaken to investigate the histological behavior of the brain with this synthetic tissue adhesive. We evaluated a total of 12 rabbits, wich were randomized into 2 groups of 6 rabbits each. Following fronto-temporo-parietal craniectomy, 1 cm of the cranium was removed and the dura mater was 0,5 cm sectioned. In the control group, dura mater was sutured with 6-0 polypropylene interrupted sutures. In the study group, the brains were covered by using 2-octyl-cyanoacrylate (high viscosity), before closurewith 6-0 polypropylene suture. Rabbits were sacrificed on day 7 following operation. Integrity of the sutures, existence of abscess, wound infection and adhesion formation were recorded. The heads were removed including the site of operation and then, the specimens were sent for histological examination. Mean weights of each study group increased. The body temperatures of the animals were normal in the two groups. The histopathological evaluation of the brains treated with the synthetic glue revealed 50 per cent of inflammatory response with focal necrosis in the cortex. Only one rabbit had a normal brain. Results under experimental conditions, indicate that this new substance, 2-octyl-cyanoacrylate, can not be considered as safe supportive material for intradural procedures directly involving the brain tissue.

Avaliação da genotoxicidade do etil-cianoacrilato, quando usado junto ao isolamenmto absoluto, através do teste do micronúcleo: um estudo in vivo / Micronucleus test evaluation of the genotoxicity of ethyl-cyanoacrylate when used in conjunction with rubber dam isolation: an in vivo study

Esta pesquisa avaliou a genotoxicidade do etil-cianoacrilato (ECA), através do teste de micronúcleos, em dez pacientes que necessitavam de tratamento endodôntico em dentes sem coroa clínica ou com esta severamente destruída e comparou seus resultados aos do grupo controle, que não recebeu ECA. Os dentes escolhidos eram incisivos, caninos e pré-molares, superiores ou inferiores. Cada sessão endodôntica, das duas que foram realizadas, variou de 90 a 120 minutos. Foram usadas, aproximadamente, quatro gotas de ECA em cada sessão, cobrindo uma área gengival de aproximadamente 13 mm em torno de todas as faces dentárias. O grupo controle, que apresentava coroa dentária, era isolado convencionalmente com grampos endodônticos, e os demais procedimentos eram iguais aos do grupo experimental. Decorridos 15 dias do tratamento endodôntico concluído, as áreas gengivais de ambos os grupos eram submetidas a três coletas de células, com intervalos de 15 dias, com uma espátula de madeira modificada (biselada). Essas amostras eram corodas através dos reagentes Schiff-Fast-Green e eram analisadas 2.000 células por indivíduo a cada coleta, pelo teste de micronúcleos. A análise estatística usando o teste t de Student ao nível de p > 0,05 não detectou diferenças estatísticas significantes para a presença de células micronucleadas (CMN) quando se compararam os resultados do grupo experimental com os do grupo controle. Concluímos que o ECA, quando aplicado nessas condições e quantidades diretamente sobre a mucosa gengival, nas duas sessões endodônticas, com propósitos de fixar o dique de borracha, não causou genotoxicidade sobre esse tecido epitelial, quando avaliado pelo teste de micronúcleos

Cytotoxic effects of cyanoacrylates used as retrograde filling materials: an in vitro analysis

Cyanoacrylate has been used in medicine and dentistry for many years. It has been used as a postextraction dressing and retrograde filling material in endodontic surgery. The aim of this study was to evaluate the cytotoxic effects of Histoacryl and other two homologue ethyl cyanoacrylates, Super Bonder and Ultrabond, on cultured fibroblasts, using the Trypan blue dye exclusion assay. The cyanoacrylates were applied to round glass coverslips, which were placed in contact with NIH 3T3 cells. After 0, 6, 12 and 24 h (short-term assay; viability) and 1, 3, 5 and 7 days (long-term assay; survival), the cells were examined under phase light microscopy and counted. The data were compared by the Kruskal-Wallis test. In the short-term experiments, only the cultures of the Ultrabond group (GIV) presented significant smaller percentages of cell viability than the cultures of the other groups (GI: control; GII: Super Bonder; GIII: Histoacryl). Although the cultures of the Super Bonder group (GII) presented smaller percentages of cell viability than cultures of the other groups (GI, GIII, GIV) at the long-term assay, this group was the only experimental group presenting a continuous and progressive cell growth. Our results have shown an in vitro biocompatibility of Histoacryl and ethyl cyanoacrylate homologues. These cyanoacrylates could therefore be of importance for endodontic purposes