Dry heat is used to sterilize materials that might be damaged by moist heat (eg, burs and certain orthodontic instruments). Although dry heat has the advantage of low operating cost and being noncorrosive, it is prolonged process and the high temperatures required are not suitable for certain patient-care items and devices.
Dry heat sterilizers used in dentistry include static-air and forced-air types.
1. The static-air type is commonly called an oven-type sterilizer. Heating coils in the bottom or sides of the unit cause hot air to rise inside the chamber through natural convection.
2. The forced-type is also known as a rapid heat-transfer sterilizer. Heated air is circulated throughout the chamber at a high velocity, permitting more rapid transfer of energy from the air to the instruments, thereby reducing the time needed for sterilization.