Avaliação in vitro da infiltração bacteriana na vedação de diferentes sistemas de implantes dentários

Abstract

Resumo: O objetivo deste estudo foi investigar in vitro a capacidade de infiltracao bacteriana atraves da interface implante/conector protetico em sistemas de implantes dentarios de conformacao hexagonal. Para a obtencao dos isolados bacterianos, amostras de saliva e subgengivais foram coletadas de 4 pacientes voluntarios que apresentavam doenca periodontal, segundo aprovacao do Comite de Etica em Pesquisa responsavel. Apos o cultivo, os micro-organismos isolados foram caracterizados por meio de testes bioquimicos e selecionados para os ensaios in vitro. No estudo da infiltracao bacteriana in vitro foram utilizados um total de 34 modelos de implantes comerciais SYSTHEXR, com os respectivos conectores proteticos de conformacoes Hexagono Interno (HI) e Hexagono Externo (HE). Os implantes testados receberam 0,1 ƒÊL de inoculo contendo mistura dos micro-organismos previamente selecionados, Aggregatibacter actinomycetemcomitans e Streptococcus oralis, os quais foram introduzidos na regiao interna do implante. Os respectivos conectores proteticos foram adaptados e fechados seguindo as especificacoes do fabricante. As unidades foram incubadas em caldo BHI (Brain Heart Infusion) esterilizado durante periodo maximo de 20 dias, com amostragens diarias visando detectar a presenca de crescimento bacteriano por meio turbidez do meio de cultura. Quando na observacao de turbidez ou apos o periodo de incubacao, as amostras eram fixadas para observacao em Microscopia Eletronica de Varredura (MEV) com aumentos variando de 20X a 4000X. Ambos os modelos de conexoes apresentaram infiltracao bacteriana, em intensidades diferentes. Apos analise, houve correlacao estatisticamente significativa entre a media das maiores distancias na interface implante/conector protetico e o nivel infiltracao bacteriana. O melhor sistema de selamento entre as conformacoes estudadas, em relacao a infiltracao bacteriana, pareceu ser a conformacao Hexagono Externo.

Abstract: The aim of this study was to investigate the in vitro bacterial leakage through the interface implant / prosthetic connector in dental implant systems of hexagonal conformation. To obtain bacterial strains, saliva and subgingival samples were collected from four volunteer patients who had periodontal disease, with the approval of the Committee for Research Ethics in charge. After culture, the microorganisms isolated were characterized by biochemical tests and selected for testing in vitro. In the study of bacterial penetration in vitro, were used a total of 34 models of commercial SYSTHEX ® implants, with the respective prosthetic connectors conformations of Internal Hexagon (HI) and External Hexagon (HE). The implants tested received 0.1 mL inoculum containing a mixture of microorganisms previously selected, Aggregatibacter actinomycetemcomitans and Streptococcus oralis, which were introduced in the inner region of the implant. Their prosthetic connectors were adapted and closed following the manufacturer's specifications. The units were incubated in BHI (Brain Heart Infusion) sterile during a maximum period of 20 days with daily sampling to detect the presence of bacterial growth by turbidity of the culture medium. When the observation of turbidity or after the incubation period, samples were fixed for observation under scanning electron microscopy (SEM) with magnification ranging from 20X to 4000X. Both models showed bacterial leakage of connections, at different intensities. After analysis, there was a statistically significant correlation between the average longer distances at the interface implant / prosthetic connector level and bacterial infiltration. The best system for sealing between the conformations studied in relation to bacterial infiltration appeared to be conformation External Hexagon.