Antimicrobial resistance of aerobes and facultative anaerobes isolated from the oral cavity

OBJECTIVES: This study evaluated the resistance to antimicrobials of aerobes and facultative anaerobes isolated from patients wearing complete dentures, patients with gingivitis and periodontitis, and periodontally health subjects. MATERIAL AND METHODS: Three hundred and four isolates were tested. The minimal inhibitory concentrations of the drugs were evaluated through the agar dilution method using Mueller-Hinton agar. RESULTS: The most active antimicrobial drugs were the carbapenems (meropenem and imipenem), and resistance to these drugs was restrict to 1.6-2.3% of the isolates, as well as ciprofloxacin and rifampin. Microbial resistance to ampicillin, amoxicillin/clavulanic acid, cefoxitin, cephalothin, amikacin, chloramphenicol and nalidixic acid was particularly high. In most cases, the resistance to β-lactams was mediated by the production of hydrolytic enzymes, especially in gram-negative enteric rods, while enterococci did not evidence production of these enzymes. The association amoxicillin/clavulanic acid was not effective in 28.3% of the tested isolates. CONCLUSIONS: The results of this investigation confirmed that the oral cavity of patients with periodontitis and gingivitis, and particularly edentulous patients wearing complete dentures could harbor microorganisms with several antimicrobial resistance markers, and these microorganisms are frequently implicated in multiresistant, systemic, oral or nosocomial infections

Evaluation of sealing between abutment and inner connection of cone morse dental implant: microgaps between implant and abutment

Introdução: Aspectos biomecânicos relacionados à adaptação de próteses fixas sobre implantes estão diretamente asso­ciados ao sucesso do tratamento. Objetivo: Avaliar in vitro a presença de microgaps na união formada pelo pilar e a conexão interna do implante dentário Cone Morse. Materiais e método: Dois grupos de implantes foram analisados. O primeiro grupo (n = 16) utilizou materiais (implantes e pilares) do mesmo fabricante, enquanto o segundo grupo (n = 16) utilizou materiais de diferentes fabricantes. Os conjuntos foram enviados para o microscópio eletrônico de varredura, onde foram tomadas as medidas dos microgaps formados entre a conexão do implante e o pilar. Resultados: Os resultados obtidos foram submetidos à avaliação estatística (Mann-Whitney-U) das medidas de dispersão e à tendência central dos valores (desvio padrão e médio). No grupo 1, a média encontrada foi de 5,69 μm e o desvio padrão (SD) foi de 8,46 μm. O grupo 2 apresentou média de 1,24 μm e SD: 0,44 μm. A diferença encontrada foi estatistica­mente significativa (p = 0,002). Conclusão: Dentro da limitação deste estudo, os resultados indicam que o grupo formado por implante e abutment de diferentes fabricantes oferece menores valores de microgaps e, portanto, uma melhor adaptação in vitro de componentes. DESCRITORES | Implantes Dentários; Dente Suporte; Microscopia Eletrônica de Varredura.Introduction: The adaptation of prostheses fixed over implants involves biomechanical aspects that are directly associated with treatment success. Objective: The aim of this in vitro study was to evaluate the presence of microgaps in the abutment/inner connection interface of cone morse dental implants. Materials and methods: Two groups of implants were analyzed. The first group (n = 16) employed single-manufacturer dental implants and abutments, whereas the second group (n = 16) combined multi-manufacturer materials. The sets were analyzed through scanning electron mi­croscopy, wherein microgaps between the implant connection and the abutment were observed. Results: Group 1 had an average microgap of 5.69 μm (SD ± 8.46 μm). Group 2 had an average microgap of 1.24 μm (SD ± 0.44 μm). A significant difference was found between the two groups (p = 0.002). Conclusion: Within the limitations of this study, results suggest that the group formed by multi-manufacturer implants and abutments (group 2) had smaller microgap values, and, therefore, a higher in vitro adaptation of components. DESCRIPTORS | Dental Implants; Dental Abutments; Scanning Electron Microscopy

Antimicrobial resistance of aerobes and facultative anaerobes isolated from the oral cavity

OBJECTIVES: This study evaluated the resistance to antimicrobials of aerobes and facultative anaerobes isolated from patients wearing complete dentures, patients with gingivitis and periodontitis, and periodontally health subjects. MATERIAL AND METHODS: Three hundred and four isolates were tested. The minimal inhibitory concentrations of the drugs were evaluated through the agar dilution method using Mueller-Hinton agar. RESULTS: The most active antimicrobial drugs were the carbapenems (meropenem and imipenem), and resistance to these drugs was restrict to 1.6-2.3% of the isolates, as well as ciprofloxacin and rifampin. Microbial resistance to ampicillin, amoxicillin/clavulanic acid, cefoxitin, cephalothin, amikacin, chloramphenicol and nalidixic acid was particularly high. In most cases, the resistance to β-lactams was mediated by the production of hydrolytic enzymes, especially in gram-negative enteric rods, while enterococci did not evidence production of these enzymes. The association amoxicillin/clavulanic acid was not effective in 28.3% of the tested isolates. CONCLUSIONS: The results of this investigation confirmed that the oral cavity of patients with periodontitis and gingivitis, and particularly edentulous patients wearing complete dentures could harbor microorganisms with several antimicrobial resistance markers, and these microorganisms are frequently implicated in multiresistant, systemic, oral or nosocomial infections