Proposal #00-03

"A Comparison Study of Aerosol Particle Contamination During Ultrasonic Instrumentation using Hands-Free, Mechanically Stabilized High Volume Evacuation (HVE) with either Standard or Funnel Shaped Attachment to HVE"

Purpose:
Aerosols produced during ultrasonic instrumentation are a potential health concern for dental hygienists. Irrigant solutions, which produce the healing effects of lavage also, combine with blood, saliva and bacteria to produce aerosolized particles. The CDCP recommends utilization of high volume evacuation (HVE), rubber dam, and patient positioning for aerosol control. These recommendations are difficult for the nonassisted dental hygienist to manage during patient care. Further study is required to find a method of evacuation that is easily managed and adapted to current practice settings.

Design:
This laboratory study will compare the degree and duration of aerosol particle contamination from ultrasonic scaling using three different evacuation techniques: a standard infraoral saliva ejector, mechanically stabilized extra-oral standard high volume evacuation (HVE) and mechanically stabilized extra-oral funnel shaped attachment to HVE. A Bobcat 25K Ultrasonic instrument will be operated at medium power for oneminute on mandibular anterior teeth in a DENTOFORM® model covered with a "Fletcher" plassein head. Air samples will be collected during and post procedure in a Zefon AIR-O-CELL Air Sampling Cassette©, specifically designed for rapid collection of a wide range of airborne aerosols. Collection will be followed by a blind evaluation of the cassettes.

Statistical Analysis
Data will be analyzed by repeated measures analysis of variance. The exposures (5), averaged over the times of observations (during, post) will be tested against a between trials error. The time of observation and the interaction of exposure will be tested against a within trials error. The observation taken before will be examined to ensure that the baseline is comparable from trial to trial. Residual analysis will be carried out to ensure that the assumptions underlying the statistical analysis are reasonably well satisfied.