RESUMO
OBJECTIVE: Information about the spectrum of microorganisms in the intraimplant cavities of two-piece dental implants is scarce. The purpose of this study was to assess the intraimplant microflora of two-piece dental implants by conventional biochemical testing, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), and 16 s rDNA gene sequencing. MATERIALS AND METHODS: Ten patients (six men and four women; average age = 66.7 years; age range = 58-78 years) received 35 two-piece titanium implants carrying ball attachments. Biofilm sampling was performed with sterile microbrushes, and nonadherent microbial samples were obtained by injection and reuptake of predefined volumes of NaCl solution. The samples were cultured and analyzed by conventional biochemical testing, MALDI-TOF MS, and 16 s rDNA gene sequencing. RESULTS: Of the 103 species detected, 27 and 33 were identified only in the biofilm and nonadherent microbial samples, respectively. Forty-three species were identified in both types of samples. CONCLUSIONS: Two-piece dental implants harbored a broad spectrum of gram-positive and gram-negative aerobes and anaerobes, especially rods and cocci. CLINICAL RELEVANCE: These findings confirm bacterial translocation from the oral cavity to intraimplant cavities. Microbiological methods as used in this study are necessary to reveal the complete vital microflora of intraimplant cavities.
Assuntos
Projeto do Implante Dentário-Pivô , Implantes Dentários/microbiologia , Microbiota , Alvéolo Dental/microbiologia , Idoso , Bactérias Aeróbias/genética , Bactérias Anaeróbias/genética , Biofilmes , Contagem de Colônia Microbiana , DNA Bacteriano/análise , DNA Bacteriano/genética , Feminino , Bacilos e Cocos Aeróbios Gram-Negativos/genética , Cocos Anaeróbios Gram-Negativos/genética , Bacilos Gram-Negativos Anaeróbios Retos, Helicoidais e Curvos/genética , Cocos Gram-Positivos/genética , Bacilos Gram-Positivos/genética , Humanos , Masculino , Pessoa de Meia-Idade , Análise de Sequência de DNA , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por MatrizRESUMO
OBJECTIVES: To study the morphological changes of the regenerating synovium in two-stage revision arthroplasty, which is the gold standard for treatment of periprosthetic joint infection. DESIGN: The authors analysed a series of synovial biopsies to examine morphological changes in healing periprosthetic tissues damaged by previous surgery and infection. METHODS: Synovial tissues from 19 patients (10 knees and 9 hips) who underwent a two-stage exchange surgery for periprosthetic infection were reviewed and correlated with clinical and laboratory findings. SETTING: Retrospective morphological study. PARTICIPANTS: Archival tissues from 19 two-stage revision arthroplasties in adult patients. RESULTS: Healing synovial tissue obtained at the reimplantation surgery showed characteristic layering: superficial fibrin exudate, immature richly vascularised granulation tissue and deeper maturing granulation tissue and fibrosis. Although increased neutrophil counts were found in the majority of cases, 2 of 19 cases showed dense infiltrates indicative of persistent infection, which correlated with positive microbiology in one case. One of the cases failed due to acetabular loosening and two cases failed due to late superinfection. One case showed a dense infiltration of eosinophils suggestive of a hypersensitivity reaction, which was subsequently proven by cutaneous tests. Foci of extramedullary haematopoiesis were detected in two cases. CONCLUSIONS: We observed characteristic morphological changes in the healing synovial tissue during reimplantation surgery for periprosthetic infection in serologically and microbiologically sterile tissues. Substantial increased counts of synovial neutrophils (>200 cells/10 high-power fields) seem to be indicative of persistent infection of the joint; therefore, prolonged antibiotic therapy should be considered in positive cases.