What tool is used to verify the sterilization cycle?

The biological indicator is the most definitive tool used to verify the sterilization cycle because it tests the effectiveness of the sterilization process. This indicator contains viable microorganisms that are resistant to the sterilization method being used. After completing the sterilization cycle, the biological indicator is incubated to see if any bacteria grow. If there is no growth, it provides strong evidence that the sterilization conditions were effective in killing the microorganisms. This rigorous method is critical in ensuring that dental instruments are safe for use and eliminates the risk of infection due to improperly sterilized tools.

In contrast, other options serve different purposes. The chemical indicator provides visual confirmation that the sterilization conditions have been met, like passing through certain temperatures, but does not guarantee that all bacteria have been killed. A physical monitor tracks essential parameters like temperature and pressure during sterilization but also does not confirm biological efficacy. A mechanical tester checks the performance of sterilization equipment but does not directly assess whether the sterilization process was successful against microorganisms. Thus, for verifying the actual effectiveness of sterilization, the biological indicator is the most reliable tool.