Cross-infection risks associated with current procedures for using high-speed dental handpieces

Area of Science:

• Dentistry
• Infection Control
• Biomedical Engineering

Background:

• Dental handpieces (drills) have internal components not typically disinfected.
• Simulated patient materials can contaminate these internal chambers.
• Contaminated material can be aerosolized during dental procedures.

Purpose of the Study:

• To investigate the potential for contamination of high-speed dental handpiece internal air turbine chambers.
• To assess the risk of cross-infection from inadequately reprocessed dental handpieces.
• To evaluate the effectiveness of current reprocessing methods in preventing contamination.

Main Methods:

• A dye solution simulating patient material was injected into or applied externally to dental handpiece waterlines.
• Internal air turbine chambers were examined for contamination.
• The dislodging of contaminated material by air and water spray was observed.

Main Results:

• Internal air turbine chambers of dental handpieces became contaminated.
• Contaminated material was retained in internal chambers, acting as a reservoir.
• Subsequent handpiece operation expelled contaminated material, diluted by water spray.

Conclusions:

• Current reprocessing methods (external wiping and flushing) may pose significant cross-infection risks.
• Patient materials can reside in non-disinfected internal handpiece parts.
• Heat-treatment of high-speed dental handpieces between patients should be considered essential for universal precautions.