Busch & Co. · Glossary

Dental Bur Terminology Glossary

From FG to FFX, KR to Cool Diamant — rotary instrument terminology packs a lot into a few letters.

Shanks & Handpieces

7 terms

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)

9 terms

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). Shop the full range in our Double Cut Burs: Busch Crosscut Carbide Cutter Collection.
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

5 terms

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

15 terms

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

4 terms

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

12 terms

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

4 terms

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.

Related guides & charts

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.

Comparison Chart Speed Chart Color Coding & ISO Guide Reprocessing Guide Part of our Dental Burs & Rotary Instruments hub