title: Long-term follow-up of turned single implants placed in periodontally healthy patients after 16 to 22 years: microbiologic outcome.
abstract: BACKGROUND
  Survival rates in implant dentistry today are high, although late failures do occur for many reasons, including peri-implant infections. The primary objective of this study is to investigate microbiota around single turned implants after 16 to 22 years. Secondary objectives are to compare teeth and implants and to correlate microbiologic, radiographic, and clinical parameters.
  
  
  METHODS
  A total of 46 patients with single implants were invited for a clinical examination. Clinical data were collected from implants and contralateral natural teeth. Radiographic bone level was measured around implants. Microbiologic samples were taken from implants, contralateral teeth, and the deepest pocket per quadrant. Samples were analyzed with DNA-DNA hybridization including 40 species. Statistical analysis was performed using Wilcoxon signed-rank tests, McNemar tests, and Spearman correlation coefficients with a 0.05 significance level.
  
  
  RESULTS
  Mean follow-up was 18.5 years (range 16 to 22 years). Tannerella forsythia (1.5 × 10(5)) and Veillonella parvula (1.02 × 10(5)) showed the highest concentrations around implants and teeth, respectively. Porphyromonas gingivalis, Prevotella intermedia, and T. forsythia were significantly more present around implants than teeth. Mean counts were significantly higher around implants than teeth for Parvimonas micra, P. gingivalis, P. intermedia, T. forsythia, and Treponema denticola. Total DNA count was correlated to interproximal bleeding index (r = 0.409) and interproximal probing depth (r = 0.307). No correlations were present with plaque index or radiographic bone level.
  
  
  CONCLUSIONS
  In the present study, bacterial counts around single implants in periodontally healthy patients are rather low. Although pathogenic bacteria are present, some in higher numbers around implants than teeth (five of 40), the majority of implants present with healthy peri-implant tissues without progressive bone loss.
authors.affiliation: Department of Periodontology and Oral Implantology, University of Ghent, Ghent, Belgium.
authors.forename: Melissa
authors.initials: M
authors.lastname: Dierens
authors.forename: Stefan
authors.initials: S
authors.lastname: Vandeweghe
authors.forename: Jenö
authors.initials: J
authors.lastname: Kisch
authors.forename: G Rutger
authors.initials: GR
authors.lastname: Persson
authors.forename: Jan
authors.initials: J
authors.lastname: Cosyn
authors.forename: Hugo
authors.initials: H
authors.lastname: De Bruyn
mesh_terms: D000293:Adolescent; D000328:Adult; D016301:Alveolar Bone Loss / Q000382:microbiology; D000539:Alveolar Process / Q000000981:diagnostic imaging; D058491:Bacterial Load; D001439:Bacteroides / Q000302:isolation & purification; D004269:DNA, Bacterial / Q000032:analysis; D019250:Dental Implants, Single-Tooth / Q000382:microbiology*; D003774:Dental Plaque Index; D017267:Dental Prosthesis Design; D005500:Follow-Up Studies; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D008137:Longitudinal Studies; D008875:Middle Aged; D009693:Nucleic Acid Hybridization; D010462:Peptostreptococcus / Q000302:isolation & purification; D010512:Periodontal Index; D010514:Periodontal Pocket / Q000382:microbiology; D016966:Porphyromonas gingivalis / Q000302:isolation & purification; D018713:Prevotella intermedia / Q000302:isolation & purification; D016300:Radiography, Bitewing / Q000379:methods; D012189:Retrospective Studies; D014070:Tooth / Q000000981:diagnostic imaging / Q000382:microbiology; D048373:Treponema denticola / Q000302:isolation & purification; D014678:Veillonella / Q000302:isolation & purification; D055815:Young Adult
chemical_list: D004269:DNA, Bacterial