National Dental Assisting Examining Board (NDAEB) Practice Exam

A _______ is used in a low-speed handpiece to place sealer and cements into tooth canals during root canal therapy (RCT).

1. Lentulo spiral

2. Endo explorer

3. Barbed broach

4. File

The correct answer is: Lentulo spiral

A lentulo spiral is specifically designed for use in a low-speed handpiece during root canal therapy to effectively place sealer and cements into the tooth canals. This instrument has a corkscrew-like shape that allows it to carry and evenly distribute materials into the confines of the canal space. The design of the lentulo spiral aids in its ability to deliver a consistent flow of sealer or cement, ensuring complete coverage within the root canal system, which is crucial for the success of the RCT. Its appropriate flexibility and rotation enable safe and efficient application without damaging the delicate canal walls. In contrast, other mentioned instruments serve different purposes. An endo explorer is primarily used for locating canal orifices and evaluating the canal morphology but is not designed to transport materials. A barbed broach, while useful for the removal of pulp tissue during the cleaning phase, lacks the capability to deliver sealing materials. A file, commonly used for canal shaping and cleaning, also does not serve as a delivery mechanism for cements or sealers but instead is crucial for preparing the canal before filling.