Inflammation associated with implants with different surface types

The aim of this study was to determine the nature of the inflammatory infiltrate associated with different transmucosal implant surfaces in dogs. Three experimental and one control single-stage implants were randomly placed on each side of the jaw in eight dogs. The transmucosal portion of the test implants consisted of an acid-etched surface (type A), a machined surface with a circumferential groove (type C) and a surface prepared by mild anodic oxidation (type D). The control was a standard machined surface (type B). In order to determine the response to the different surfaces, plaque control was carried out twice weekly following placement of the implants for the entire period of the experiment. At 6 months, gingival biopsies and plaque samples were obtained. The area of inflammatory infiltrate and the nature of the infiltrating cell types were determined using immunohistology. Real-time polymerase chain reaction was used to identify putative periodontal pathogens. Inflammatory infiltrates were associated with all implant surfaces and were commonly found subepithelially and perivascularly. T cells were the predominant infiltrating cell type in all lesions, associated with the different surfaces. In all lesions the CD4 : CD8 ratio was approximately 2 : 1. Statistical analysis showed that the type C surface (machined surface with a groove) had significantly larger inflammatory infiltrates than the type B surface (machined surface without a groove; P < 0.05). No statistically significant differences were found with respect to the size of the inflammatory infiltrates or in terms of the nature of infiltrating cells. However, despite the intensive plaque control regime, plaque was present on all implant surfaces at the time of biopsy 6 months after placement. All implants had similar numbers of Tannerella forsythia, Fusobacterium nucleatum and Porphyromonas gingivalis. Actinobacillus actinomycetemcomitans, was not detected in any sample. These results suggest that the development of inflammation associated with implants is independent of surface type, but is nevertheless associated with the presence of plaque. The different surfaces had no influence on the nature of the infiltrate, with T cells being the predominant cell type in all lesions. Finally, the different implant surface types seemed not to influence the peri-implant microbiota. However, the presence of the circumferential groove tended to be associated with larger infiltrates. Whether this is due to increased plaque accumulation remains to be determined

Isolamento e identificação da microbiota periodontal de cães da raça Pastor Alemão Isolate and identify of periodontal microbiota of German Shepherd dogs

A microbiota indígena gengival de cães não está totalmente descrita, sendo sua identificação uma etapa importante no estabelecimento da etiopatogenia e terapia da doença periodontal. O objetivo deste trabalho foi isolar e identificar a microbiota periodontal de cães da raça Pastor Alemão, considerando sítios saudáveis e com doença periodontal. Foram utilizados 29 cães, com idade variando de três a seis anos, sendo analisados espécimes clínicos de sítios periodontais saudáveis de 12 cães e sítios com periodontite de outros 17. Foram isoladas 672 amostras microbianas, com predomínio dos gêneros Pasteurella, Staphylococcus, Porphyromonas e Fusobacterium. A microbiota dos sítios saudáveis equiparou-se à dos sítios doentes, tratando-se de uma microbiota indígena. A microbiota dos sítios doentes apresentou-se aumentada em relação a dos sítios saudáveis, indicando mudança do ambiente do sítio periodontal.<br>The indigenous gingival microbiota of dogs is not totally described, although such identification is an important step to establish the etiopathogenesis and adequate therapy for the periodontal disease. The aims of this study were to isolate and identify the periodontal microbiota of German Shepherd dogs from healthy and with periodontal desease sites. Twenty nine German Shepherd dogs from three to six years of age were used in this study. Clinical specimens were analysed from healthy periodontal sites of 12 dogs and sites presenting gingivitis of 17 dogs. A total amount of 672 microbial samples, were isolated where the predominant genera were Pasteurella spp., Staphylococcus spp., Porphyromonas spp. and Fusobacterium spp. The microbiological population of the affected sites was similar to the healthy sites, consisting on an indigenous microbiota. The microbiota on the affecteded sites was higher in number than on the healthy sites, showing change in the environment of the periodontal sites