Final answer:
Instruments must be absolutely dry for dry-heat sterilization to prevent rust or an ash layer. This contrasts with moist-heat sterilization methods like autoclaving, which is more effective in penetrating and killing microbes, including resistant endospores.
Step-by-step explanation:
Instruments must be absolutely dry when undergoing dry-heat sterilization to avoid rust or an ash layer formation. Dry-heat sterilization involves the use of high temperatures for a prolonged period to destroy all microorganisms. This method includes direct flaming, incineration, or using a dry-heat sterilizer such as an oven. In contrast, moist-heat sterilization, such as autoclaving, uses steam above the boiling point of water to better penetrate and kill microorganisms, including endospores which can survive boiling temperatures.
Understanding the distinction between these two methods is critical as applying the wrong procedure can damage instruments or fail to achieve proper sterilization. Autoclaves, which rely on moist heat, are considered one of the most effective means of sterilization, and it is imperative that instruments are kept dry in the context of dry-heat protocols to prevent rusting or ash debris after sterilization.