The several types of steam sterilizers that are in use.
1. Lab Autoclave
2. Hospital dressing sterilizer
3. Bowl & instrument sterilizer
4. Rapid cooling sterilizer
Parameter:
121OC (250O F) for 15 minutes at 15 psi or 132OC (270O F) for 3-7 mins at 30 psi (flash sterilization) for unwrapped instruments.
Add 5 minutes for moderately wrapped packs.
The typical dental office steam sterilizer usually operates through 4 cycles:
- The heat up cycle
- The sterilizing cycle
- The depressurization cycle
- The Drying cycle
After adding the water one loads the chamber, closes the door & turns on the unit & the heat up cycle begins to generate steam.
The steam pushes out the air in the chamber (in a gravity steam sterilizer ) or a vacuum is drawn (in a vacuum steam sterilizer ) & when the set temperature is reached, the sterilization cycle begins. The sterilizer maintains the temperature for the set time, usually ranging from 3-30 minutes. At the end of the sterilizing cycle, the depressurization cycle begins & steam is slowly released, with decrease in temperature & pressure. At the end of this cycle, all the items inside are wet & the drying cycle is initiated. Most steam sterilizer manufacturers provide drying instructions & some even may have a programmed closed door or open during cycle.
Some sterilizers have a post sterilizer vacuum cycle to facilitate drying. Other steam sterilizers pull in fresh air through a microbial filter. Others have an automatic open door drying cycle that maintains the heat inside chamber to evaporate the remaining water but the chamber is opened to the air so that water vapour can escape and items can dry.
The cooling of the warm pack should be done slowly to avoid the formation of condensation on the instruments. One should not place warm packs under air conditioning or cool air vents.