The sterility of the root canal during treatment is assessed by
**Core Concept**
Sterilization of the root canal is crucial in endodontic treatment to prevent reinfection and ensure the success of the procedure. This involves eliminating or reducing microbial contamination within the canal to prevent the growth of bacteria, fungi, and other microorganisms.
**Why the Correct Answer is Right**
The correct answer is **C. Apexification test**. The apexification test is a method used to determine the sterility of the root canal by assessing the ability of the canal to resist the ingress of a dye or a radiopaque material. This test involves placing a material, such as a radiopaque paste or a dye, into the canal and observing whether it remains within the canal or leaks past the apical foramen. The presence of a dye or radiopaque material at the apex indicates that the canal is not sterile.
**Why Each Wrong Option is Incorrect**
* **Option A:** This option is not a recognized method for assessing the sterility of the root canal.
* **Option B:** This option is incorrect as it refers to a different aspect of endodontic treatment, specifically the removal of infected pulp tissue.
**Clinical Pearl / High-Yield Fact**
The apexification test is a simple yet effective method for assessing the sterility of the root canal, and it should be performed as part of a thorough endodontic treatment protocol.
**Correct Answer:** C. Apexification test