Dental Bur Terminology Glossary
From FG to FFX, KR to Cool Diamant — rotary instrument terminology packs a lot into a few letters. This glossary defines the shanks, cuts, grits, shapes, numbering systems, and Busch product lines you'll meet across our catalog, with links to our reference charts where a term has its own deep-dive.
| Shanks & Handpieces | |
| FG (Friction Grip) | 1.6 mm smooth shank held by friction in high-speed turbine handpieces. The standard clinical shank for preparation work. |
| RA (Right Angle / Latch-Type) | 2.35 mm shank with a latch groove, for slow-speed contra-angle handpieces. Busch's German designation is W (Winkelstück). |
| HP (Handpiece / Straight) | 2.35 mm plain shank for straight laboratory and slow-speed handpieces. Busch lab designations HST and PM refer to the same straight-handpiece format. |
| FG-XL / FG-LG / RA-L | Length variants: extended shanks that improve reach for posterior access or deep preparations. L = long, XL = extra long. |
| HP-SH / GR.HP-SH | Special laboratory shank formats; GR indicates a larger shank diameter. Verify handpiece compatibility before use. |
| Contra-angle | An angled slow-speed handpiece taking RA (latch-type) instruments. |
| Turbine | An air-driven high-speed handpiece taking FG instruments, operating in the hundreds of thousands of RPM. |
| Cuts & Toothing (Carbide) | |
| Crosscut (CC) | Transverse notches across the blades that break chips and increase cutting aggressiveness. US catalogs number crosscut fissure burs in the 550–560s (e.g., 557). |
| Fine Crosscut (FX) / Extra Fine Crosscut (FFX) | Progressively finer crosscut patterns for smoother surfaces and finishing work. |
| SX-Cut / SXM-Cut | Busch's low-vibration excavating cuts for carbide round burs; the SXM version adds an extremely slim neck for visibility in minimal cavity openings. |
| XA-Cut / XTi-Cut | Busch special cuts: XA for safe, controlled removal; XTi optimized for milling titanium. |
| X-Cut (Double Cut) | Crossed toothing on lab cutters; graded from SGX (very coarse) through X (medium) to FX and FFX (fine and super-fine). |
| GQSR-Cut | Busch's coarse straight power cut for non-hardening and soft acrylics. |
| MQS-Cut | Medium cut with crosscut for soft acrylics and splint materials. |
| Diamond Cut (D) | Carbide crown cutters with a diamond-pattern toothing (34D, 36RD) for universal use across alloys and metal-ceramics. |
| Finishing Cut (F / UF) | Multi-blade fine toothing on finishing carbides; F = fine (yellow ring), UF = ultra fine (white ring). |
| Diamond Grits & Rings | |
| Grit | The diamond particle size bonded to the working part. From coarsest to finest: Super Coarse (black ring), Coarse (green), Medium (no ring — the standard), Fine (red), Extra Fine (yellow). |
| Ring Color | The colored band on a diamond's shank identifying its grit. See our Color Coding Guide for the full chart. |
| 6- / 8-Prefix Figures | Busch encodes grit in the figure number: 6855 is the coarse and 8855 the fine version of base figure 855. |
| EF Suffix | Extra fine grit variant of a figure (e.g., 862EF), yellow ring. |
| Mega Coarse | The extra-aggressive grit of Busch's DiaTwister sintered lab instruments. |
| Shapes | |
| Round (Rosehead) | Spherical head; the classic excavating shape. US numbers ¼–10. |
| Inverted Cone | Head tapering toward the shank, for undercuts and flat cavity floors. US numbers 33½–41. |
| Straight Fissure (Cylinder) | Parallel-sided head for cavity walls; flat-end. US 55–63 plain, 555–563 crosscut. |
| Tapered Fissure (Cone) | Convergent-sided fissure shape. US 168–172 plain, 698–704 crosscut. |
| Pear | Rounded, pear-shaped head for conservative access and amalgam preparation. US 330–333. |
| Football (Egg) | Olive-shaped head for occlusal and lingual reduction. |
| Flame | Slender pointed head for interproximal finishing and gingival margins. |
| Bud | Short pointed-oval head for occlusal anatomy and finishing. |
| Taper Round / Taper Flat | Cone with rounded or flat end; the round-end taper (856-type) is the workhorse of crown preparation. |
| KR (Rounded Edge) | Suffix on cylinder figures (835KR) marking rounded edges for defined internal line angles without sharp corners. |
| Torpedo | Taper with an ogival (bullet-nosed) end for chamfer margins. |
| Barrel | Wide, barrel-profiled head for lingual reduction (811-type). |
| Wheel / Disc | Thin, wide shapes for separating and contouring; discs are the large flat versions, often unmounted. |
| Cup / Point | Polisher forms: hollow cup for cusps and broad surfaces, point for fissures and grooves. |
| Diabolo | Hourglass-shaped head, waisted in the middle (813-type). |
| Numbering Systems | |
| US Number | The traditional American shape numbering (¼, 1–8, 33½, 557, 701…) used by Midwest, SS White, and Premier. Leads the title of every applicable product in our store. |
| Figure Number | The German/DIN shape number (801, 835, 856…) shared by Busch, Komet, Meisinger, and other DIN-system manufacturers. |
| ISO 6360 Number | The five-group international code on the packaging describing material, shank, shape, grit, and size — decoded in our Color Coding Guide and the basis of our Comparison Chart. |
| Size (ISO Ø) | The last three digits: maximum head diameter in tenths of a millimetre (014 = 1.4 mm). |
| Materials & Product Lines | |
| Tungsten Carbide (HM) | Sintered hard metal for blades that cut rather than grind; the standard for excavation, fissure work, and lab cutters. |
| Diamond Instrument | Natural or synthetic diamond grit bonded to a steel blank; grinds hard substance — enamel, ceramics, zirconia. |
| Tungsten Vanadium Steel | Tough, hard steel used for classic lab and finishing burs. |
| KERA Ceramic Cutters | Busch's all-ceramic cutters — white, up to 60% lighter than carbide — for pre-sintered zirconia, acrylics, and splints. |
| Cool Diamant | Gold-plated premium diamond series with flow-optimized coating for cooler, more efficient grinding. |
| Ziramant | Special diamond coating engineered for cutting sintered zirconia. |
| DiaTwister | Sintered mega-coarse diamond lab instruments for rapid removal. |
| Shorties / Midis | Busch's shortened lab cutter formats (S / M prefixes) for compact handling. |
| Perio Pro / LongLife Perio Pro | Slender periodontal diamonds and carbides for subgingival finishing and root work. |
| Micro Prep (MI) | Small-diameter, long-neck diamonds for minimally invasive preparation. |
| Steri-Safe | Busch's validated, autoclavable bur block system — see our Reprocessing Guide. |
| Mandrel | A shank-mounted carrier for unmounted discs, wheels, and polishing accessories. |
| Use & Care | |
| min⁻¹ / RPM | Revolutions per minute. Larger heads demand lower speeds — see our Speed Chart. |
| Concentricity (Running True) | How perfectly the head rotates on the shank axis; poor concentricity causes vibration, chatter, and patient discomfort. A hallmark of German manufacturing tolerances. |
| Single-Use Symbol | The crossed-out '2' on packaging: the instrument must not be reprocessed or reused. |
| Working Part / Neck / Shank | The three zones of a rotary instrument: the cutting or grinding head, the connecting neck, and the shank gripped by the handpiece. |
All Busch instruments are manufactured by Busch & Co. in Engelskirchen, Germany. See also our Comparison Chart, Speed Chart, Color Coding & ISO Guide, and Reprocessing Guide.
