Figure 10-9.Sterile storage cabinet.
suitable for all dental items. As a basic dental assistant,
you will need to know several approved methods of
Steam Heat Sterilization
Steam under pressure (saturated steam) is the most
effective means of sterilization for almost all items
used in dentistry. To achieve sterility, moist heat under
pressure must come in contact with all surfaces of all
items for the appropriate length of time. To effectively
sterilize items using saturated steam, the temperature
of the steam throughout the load must be high enough
to destroy the most resistant micro-organisms in the
time allotted for sterilization. For example, some
spores can withstand temperatures above the normal
boiling point of water (212°F or 100°C); so the
relationship of temperature to spore killing power is
critical. Steam temperature and exposure time, not
pressure, are crucial components of this process.
Pressure is used only to raise the temperature of the
steam and, in itself, has nothing to do with microbial
killing action. At 15 pounds per square inch (psi), the
boiling point increases to 121°C (250°F), a
temperature at which all known organisms are killed.