The basic difference between K files and reamers is:
- A- The number of spirals or flutes per unit length.
- B- The geometric cross section.
- C- The depth of flutes.
- D- The direction of the spirals.
The geometric cross section is the key difference between K files and reamers in endodontic procedures.
Here's a breakdown of each option:
A. The number of spirals or flutes per unit length:
While the number of flutes can differ slightly between K files and reamers, it's not the primary distinguishing factor. Both types typically have 4-8 flutes per inch.
B. The geometric cross section:
This is the main difference! K files have a square cross-section, while reamers have a triangular cross-section.
C. The depth of flutes:
The depth of flutes (sometimes called "rake angle") can vary slightly depending on the specific instrument, but it's not a defining characteristic between K files and reamers.
D. The direction of the spirals:
Both K files and reamers have spirals that run in the same direction (clockwise) for cutting and retrieval.
Geometric Cross-section Difference:
Here's how the geometric cross-section difference affects their functions:
- K files:
With their square cross-section, K files have more cutting surface area and are better suited for initial penetration and enlargement of the root canal with a filing motion.
- Reamers:
The triangular cross-section of reamers provides greater flexibility and makes them more effective for reaming and smoothing the canal walls with a rotary motion.
