title: Effectiveness of two devices designed to prevent fluid retraction in a high-speed handpiece.
abstract: BACKGROUND
  Contaminated fluid can be retracted into the turbine air chamber of a high-speed handpiece when it stops rotating.
  
  
  OBJECTIVE
  This study attempted to evaluate 2 operating systems recently equipped with antiretraction devices installed inside the handpiece (Kavo) or inside the unit (Castellini) and to compare the results with those obtained from an operating system without any antisuction device (Bien Air).
  
  
  METHODS
  Two test conditions (bur immersed approximately 5 mm into a dye solution or completely immersed in dye solution) were conducted using potassium bichromate dye to simulate a fluid contaminant.
  
  
  RESULTS
  During the first procedure dye influx for the Kavo unit was 0.08 +/- 0.1 microL, 0.06 +/- 0.1 microL for the Castellini unit, and 12.4 +/- 5.2 microL for the Bien Air unit (F=28.3; P <.01). During the second procedure, the results of the dye influx were Kavo unit 2.52 +/- 1.3 microL, Castellini unit 0.1 +/- 0.1 microL, and Bien Air unit 22.22 +/- 4.0 microL (F=123; P <.01). Mean values were significantly different between Castellini and Kavo units during the second procedure.
  
  
  CONCLUSIONS
  Antisuction devices can reduce dye penetration into the air chamber of a high-speed handpiece. Better results may be obtained with devices installed inside the unit and designed to increase the air pressure in the air chamber when the turbine stops running.
authors.affiliation: University of Bologna, Bologna, Italy. montebu@alma.unibo.it
authors.forename: L
authors.initials: L
authors.lastname: Montebugnoli
authors.forename: G
authors.initials: G
authors.lastname: Dolci
mesh_terms: D016902:Air Pollution, Indoor / Q000517:prevention & control; D000704:Analysis of Variance; D003754:Dental High-Speed Equipment; D004866:Equipment Contamination / Q000517:prevention & control*; D019552:Infection Control, Dental / Q000295:instrumentation*; D013396:Suction / Q000295:instrumentation