Dry heat may be used to sterilize patient-care items that might be damaged by moist heat (e.g., burs and certain orthodontic instruments). Although dry heat has the advantages of low operating cost and being noncorrosive, it is a prolonged process and the high temperatures required are not suitable for the sterilization of many instruments and devices. There are two types of dry-heat sterilizers used in dentistry: static-air and forced-air types.
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. The forced-air type is also known as a rapid heat-transfer sterilizer. Heated air is circulated throughout the chamber at a high velocity, which permits more rapid transfer of energy from the air to the instruments, thereby reducing the time needed for sterilization.2,3