Straight Fissure Burs | Cylinder Shape

Straight fissure burs — parallel-sided cylinders with a flat end — for cavity walls, crown sectioning, and amalgam preparation. The collection covers plain-cut US numbers 55–63 and the crosscut 555–563 family, including the legendary 557 and 558, plus long (L) and round-end (R) variants.

Crosscut toothing breaks chips for aggressive, cool cutting through enamel, dentine, and metal; plain cuts leave smoother walls. Busch grinds both with the flute precision that made German fissure burs the standard.

FAQ

What is a 557 bur? The US No. 557 is the crosscut straight fissure bur — Busch figure 31, size 010 — arguably the most-used carbide in operative dentistry for cavity preparation and crown removal.

Plain cut or crosscut? Crosscut (555–563) cuts faster and cooler and is preferred for bulk work and sectioning; plain cut (55–63) leaves smoother cavity walls for finishing.

Where are these burs made? Every instrument in this collection is manufactured by Busch & Co. in Engelskirchen, Germany — an ISO 13485-certified specialist in rotary precision instruments since 1905 — and ships fast from our US warehouse.

Reference resources: Bur Comparison Chart · Speed Chart · Color Coding & ISO Guide · Glossary