Which type of sterilization method uses heated steam to kill microorganisms?

The method that uses heated steam to kill microorganisms is steam under pressure, commonly referred to as an autoclave. This sterilization technique involves the use of pressurized steam to achieve temperatures sufficient to eradicate a wide range of pathogens, including bacteria, viruses, and spores. The steam penetrates the materials being sterilized, ensuring that it reaches the surfaces where microorganisms may reside.

The effectiveness of this method is due to both the high temperature and pressure applied, which work together to ensure thorough sterilization within a specific time frame. Typically, autoclaving is performed at a temperature of 121 degrees Celsius (250 degrees Fahrenheit) under pressure for at least 15 to 30 minutes, depending on the materials being processed.

This method stands out for its ability to sterilize various dental instruments and equipment efficiently, making it a cornerstone of infection control in dental practice. It contrasts with the other methods listed, which utilize different mechanisms or conditions for sterilization: chemical vapor uses chemicals and heat, dry heat relies on high temperatures without moisture, and microwave sterilization is not typically recognized as a standard sterilization method in dental practices.