What is the recommended volume of water for an air flush?

Air Flush Volume for Dental Unit Waterlines

The recommended volume for an air flush is a minimum of 20-30 seconds of air and water discharge after each patient from any device connected to the dental water system that enters the patient's mouth.

Recommended Air Flush Protocol

According to the CDC guidelines for infection control in dental healthcare settings, proper maintenance of dental unit waterlines is essential to prevent biofilm formation and bacterial contamination 1. The specific recommendations for air flush include:

• Duration: Discharge water and air for a minimum of 20-30 seconds after each patient 1
• Applicable devices: This applies to any device connected to the dental water system that enters the patient's mouth, including:
  • Handpieces
  • Ultrasonic scalers
  • Air/water syringes 1

Rationale and Importance

The purpose of this air flush procedure is to:

1. Remove potentially contaminated water that may have been drawn back into the waterline during treatment
2. Reduce biofilm formation in dental unit waterlines
3. Help maintain water quality below the EPA standard of <500 CFU/mL of heterotrophic water bacteria 1

Additional Water Quality Considerations

Beyond the air flush procedure, dental professionals should also:

• Use water that meets EPA regulatory standards for drinking water (<500 CFU/mL of heterotrophic water bacteria) for routine dental treatment 1
• Consult with dental unit manufacturers for:
  • Appropriate methods and equipment to maintain recommended water quality
  • Guidance on monitoring water quality
  • Periodic maintenance of antiretraction mechanisms 1

Special Circumstances: Boil-Water Advisories

During boil-water advisories, special precautions must be taken:

• Do not deliver water from the public water system to patients through dental equipment
• After the advisory is lifted, flush dental waterlines and faucets for 1-5 minutes before patient care
• Disinfect dental waterlines as recommended by the manufacturer 1

Common Pitfalls to Avoid

1. Insufficient flushing time: Flushing for less than the recommended 20-30 seconds may not adequately clear contaminated water from the lines
2. Inconsistent application: Failing to flush all devices that enter the patient's mouth
3. Neglecting manufacturer recommendations: Different dental units may have specific maintenance requirements that should be followed
4. Inadequate monitoring: Regular water quality testing should be performed according to manufacturer recommendations

The 20-30 second air flush procedure is a simple yet critical infection control measure that should be incorporated into routine practice between all patients to ensure patient safety and maintain proper dental unit water quality.