title: Microbiology and cytokine levels around healthy dental implants and teeth.
abstract: BACKGROUND
  Elicitation of the relationship of periodontopathogens and pro-inflammatory cytokines to bone resorption and formation is significant to a growing body of research known as osteoimmunology. It is essential that clinically healthy peri-implant and periodontal sites are studied to contribute comparison data for investigations that are addressing diseased sites.
  
  
  OBJECTIVE
  The purpose of this study was to describe levels of selected pro-inflammatory cytokines in clinically healthy peri-implant and periodontal sites, and to examine whether cytokine levels may be related to specific bacterial/viral pathogens.
  
  
  METHODS
  Eleven subjects (mean age 56.2 +/- 10) participated in the study. Subgingival microbial samples were cultured for periodontopathic bacteria. Gingival crevicular fluid samples were analyzed by nested polymerase chain reaction for Cytomegalovirus (HCMV) and were tested for the quantification of Interleukin (IL)-8, IL-1beta, IL-6, IL-10, Tumor Necrosis Factor (TNF)-alpha, and IL-12p70 using flow cytometry (FACS). Findings for microbiota composition and cytokine levels were compared between implants and teeth (chi square, Kruskall-Wallis, Mann-Whitney; p < or = .05).
  
  
  RESULTS
  Both the frequency (%) and levels (%) of periodontopathic bacteria were higher around teeth than implants. The concentration (picogram per milliliter) of cytokines was more prominent around implants than teeth, reaching nearly twofold differences in some instances. Cytokine levels were higher when the sites analyzed were positive for any bacteria tested. HCMV was not detected.
  
  
  CONCLUSIONS
  Pro-inflammatory cytokine production was unrelated to heavy bacterial challenge. Nevertheless, when periodontopathic bacteria were detected by culture, cytokine levels were increased around both implants and teeth. Studies are needed to investigate the pro-inflammatory cytokines (especially IL-1beta and TNF-alpha) produced in spite of minimal bacterial accumulation.
authors.affiliation: University of Southern California School of Dentistry, Dental Science Center-DEN, Los Angeles, CA 90089-0641, USA. nowzari@usc.edu
authors.forename: Hessam
authors.initials: H
authors.lastname: Nowzari
authors.forename: Javier Enrique
authors.initials: JE
authors.lastname: Botero
authors.forename: Marina
authors.initials: M
authors.lastname: DeGiacomo
authors.forename: Maria C
authors.initials: MC
authors.lastname: Villacres
authors.forename: Sandra K
authors.initials: SK
authors.lastname: Rich
mesh_terms: D001421:Bacteria, Anaerobic / Q000302:isolation & purification; D016207:Cytokines / Q000032:analysis*; D003587:Cytomegalovirus / Q000302:isolation & purification; D004269:DNA, Bacterial / Q000032:analysis; D004279:DNA, Viral / Q000032:analysis; D003758:Dental Implantation, Endosseous; D015921:Dental Implants; D003773:Dental Plaque / Q000276:immunology / Q000382:microbiology*; D005260:Female; D005883:Gingival Crevicular Fluid / Q000276:immunology* / Q000382:microbiology* / Q000821:virology; D006801:Humans; D007378:Interleukins / Q000032:analysis; D008297:Male; D008875:Middle Aged; D010519:Periodontium / Q000276:immunology / Q000382:microbiology; D016133:Polymerase Chain Reaction; D014409:Tumor Necrosis Factor-alpha / Q000032:analysis
chemical_list: D016207:Cytokines; D004269:DNA, Bacterial; D004279:DNA, Viral; D015921:Dental Implants; D007378:Interleukins; D014409:Tumor Necrosis Factor-alpha