title: Detection of oral streptococci in dental unit water lines after therapy with air turbine handpiece: biological fluid retraction more frequent than expected.
abstract: OBJECTIVE
  Oral streptococci detected in water from dental unit water lines (DUWLs) are a surrogate marker of patients' biological fluid retraction during therapy. We investigated oral streptococci detection rate in DUWLs in a representative sample of private offices in real-life conditions.
  
  
  METHODS
  Samples of nondisinfected water (100 ml) were collected from the DUWL designated for the air turbine handpiece in 81 dental units, immediately after dental treatment of patients with extensive air turbine handpiece use. Water was filtered and plated on a selective medium for oral streptococci and, morphologically, typical colonies of oral streptococci were counted. The lowest detection limit was 0.01 CFU/ml.
  
  
  RESULTS
  The oral streptococci detection rate was 72% (95% CI: 62-81%), with a mean level of 0.7 CFU/ml. Oral streptococci detection was not affected by handpiece age or dental treatment type, but was associated with dental unit age.
  
  
  CONCLUSIONS
  Biological fluid retraction into DUWLs during patient treatment and, possibly, the risk for patient-to-patient blood- or air-borne pathogen transmission are more frequent than expected.
authors: Department of Public Health & Infectious Diseases, Sapienza University, Piazzale Aldo Moro 5, 00185 Rome, Italy. stefano.petti@uniroma1.it
authors: Stefano
authors: S
authors: Petti
authors: Catia
authors: C
authors: Moroni
authors: Giuseppe Alessio
authors: GA
authors: Messano
authors: Antonella
authors: A
authors: Polimeni
mesh_terms: D003770:Dental Offices; D006801:Humans; D013291:Streptococcus / Q000302:isolation & purification*; D019246:Tooth Preparation / Q000379:methods; D014871:Water Microbiology; D014876:Water Pollution