Prevacuum steam sterilizer

A prevacuum sterilizer has a vacuum pump that removes the air from the chamber first, so steam reaches every part of the load faster, even inside wrapped packs. Because air left in the chamber would block the steam, these units need an air-removal test called a Bowie-Dick test. CDC guidance says to run it each day the sterilizer is used, before the first load, in an empty chamber. A common minimum cycle is 132 C (270 F) for 4 minutes for wrapped items.

How to spot it

• Looks much like a regular autoclave; the manual, label or cycle menu will say vacuum or prevacuum.
• You may hear a pump working in pulses at the start of the cycle.
• The office keeps Bowie-Dick test packs or sheets near it.

What it is used for

• Sterilizes wrapped packs, cassettes and hollow items such as handpieces.
• Starts the day with an air-removal (Bowie-Dick type) test before the first real load.

Safety and care

• If the unit fails the air-removal test, do not use it until it is inspected and passes.
• Same burn and loading rules as any autoclave. Follow the manufacturer's instructions for care.

Related

• Steam autoclave (tabletop steam sterilizer)
• Cassette autoclave

Sources: CDC. Guidelines for Infection Control in Dental Health-Care Settings, 2003. MMWR 2003;52(RR-17), CDC. Guideline for Disinfection and Sterilization in Healthcare Facilities (2008): Steam Sterilization, CDC. Guideline for Disinfection and Sterilization in Healthcare Facilities (2008): Sterilizing Practices