Which tool is used to enlarge and smooth the canal during preparation?

• A. Root canal file
• B. Root canal reamer
• C. Condense GP against wall to eliminate gaps
• D. Rotary paste-filler

Answer: (B)

Enlarging and smoothing the canal during preparation is achieved with a root canal reamer. Reamers are designed with cutting edges that engage dentin along the canal walls, allowing you to widen the canal and leave a smoother, more uniform surface as you progress. This makes the canal easier to irrigate and later obturate effectively. In contrast, a general root canal file is primarily used for scouting and cleaning to establish patency, not to enlarge and refine the canal as efficiently. The other options relate to obturation techniques (condensing gutta-percha or using a paste filler) and are not involved in shaping the canal during preparation.