DLA 1203- Exam 3

1. Rotary Instruments

2. Dental Rotary Instruments
Parts of bur
Shank
Neck
Head
Straight shank
Latch-type shank
Friction-grip shank
Head
Neck
Shank
© Cengage Learning 2013

4. Burs
 Materials that make up the bur are either steel or tungsten carbide.
 You will find burs not only used chairside, but also in dental
laboratories.
 The use of burs is as follows: cavity preparation, finishing and polishing
restorations, surgical procedures, and dental appliance adjustments.
 The shank is designed to accommodate the dental handpieces.
 Lengths of bur shanks vary and are designated by the letter ‘S’ for
short, and “L” for long

5. Types of Burs
 Cutting
 6 blades
 Diamond
 Finishing
 Surgical
 Laboratory
 Fissurectomy

6. The burs are divided into categories
according to their use.
 The cutting burs are separated into different shapes and sizes.
 These burs are numbered, and students should learn the number ranges.
 The diamond burs are used for the cavity preparation and finishing the
restoration.
 The finishing burs come in different shapes and are used to smooth the
restoration.
 The surgical and laboratory burs may look similar, but the surgical burs are used
in the mouth, and the laboratory burs are used on fixed and removable
prostheses.
 Fissurotomy burs are extremely small and are used to explore the occlusal
surface to treat and diagnosis while maintaining tooth structure.

7. Bur Numbers
Describe:
Shape
Size
Variation

8. Round bur
 Used first to open the cavity and remove carious
tooth structure.

9. Inverted cone bur
 Removes carious tooth structure and makes undercuts in the
preparation.

10. Straight fissure plain
Straight fissure cross-cut burs
 Forms the
cavity walls of
the
preparation.

11. Plain Tapered fissure bur and
Cross-cut tapered fissure bur
Forms divergent
walls of the cavity
preparation.

12. End-cutting bur
 Forms the shoulder for crown preparations.

13. Wheel bur
 Forms retention in preparations.

14. Pear bur
 Opens and extends the cavity preparation.

15. Diamond Burs
 Used for rapid reduction of tooth structure during cavity preparation, polishing
and finishing composite restorations, and occlusal adjustment.
 also used for bone and gingival contouring during surgical procedures.
 come in a wide variety of shapes, sizes, and grits.
 Diamond particles are embedded in the bur head through an electroplating or a
bonding process.
 The burs are either color coded for easy grit identification or have letters following
the bur numbers to indicate the grit
 These burs may be specifically designed for a certain procedure, such as finishing,
trimming, or composite restorations.

16. Diamond Bur- Football
Color-coded

17. Various shaped
diamond burs in
course, fine, and
extra fine grit

18. Diamond burs

19. Finishing Burs
 Smooth, trim, and finish metal restorations
and natural tooth–colored materials.
 Can have up to 30 blades for ultra-fine
finishing.
 Increased number of blades
 Come in a variety of shapes and sizes, similar
to the cutting burs.
 They are identified by the manufacturer's
number.
 Some are color coded for easy identification.
 A red band indicates 8 and 12 blades on the
finishing bur
 A yellow band indicates 16 and 20 blades
 A white band indicates a 30-blade finishing bur

20. Surgical burs
 Surgical burs are used in a low-speed handpiece to reduce and contour the
alveolar bone and tooth structure.
 The heads of surgical burs come in various sizes and shapes and have long
shanks

21. Laboratory burs
 Laboratory burs are used to adjust acrylic materials, such as partials, dentures, and custom trays.
 They are also used on plaster, stone, and metal materials.
 Laboratory burs have long shanks and large working ends.
 These burs come in a variety of sizes and shapes.
 Sometimes they are referred to as vulcanite or acrylic burs

22. Fissurotomy Burs
 Extremely small (0.33 mm).
 Made of carbide
 Used to explore the occlusal surface and to
allow for effective diagnoses and treatment
while preserving healthy tooth structure.
 Cut quickly, leaving a smooth, minimally
invasive groove in suspicious pits and
fissures.
 Designed as depth gauges, giving the burs
minimal access to the fissures and
permitting virtually pain-free fissure cavity
preparation

23. Abrasives
 Nonbladed instruments used to finish and polish restorations
and appliances
 Categorized by shape and materials from which they are made
E.g., rubber, stone, sandpaper
 There are some abrasives that are used for cutting.
 The shapes that categorize abrasives are as follows:
Discs
Points
Wheels

24. Mandrels
 Mandrels
Rods of various lengths
used in low-speed
handpieces

25. Mandrels
Mandrels are used with different
abrasives, which are either mounted to
the mandrel or unmounted.
They come in three different shanks:
Latch
friction grip
straight.

26. Discs
 Used to polish, smooth, and adjust restorative
materials and dental appliances
 The types of discs are as follows:
 sandpaper discs,
 diamond discs
 carborundum (also known as Jo-Dandy discs and
separating discs).
 They are thin and brittle and break easily.

27. Sandpaper Discs
• Used to finish and polish all types
of restorations and appliances.
• These materials are mounted on
one side of the paper disc.
• Flexible
• Applied to surfaces on one side
only
• Come with a metal or pin-hole
center
• Made from garnet, sand, emery,
and cuttlefish

28. Rubber Wheel disc
• Made of rubber material
impregnated with an
abrasive agent.
• Come mounted and un-
mounted
• Used for finishing and
polishing

29. Rubber Points
 Used for:
Finishing
Polishing
Defining anatomy in amalgam
 Rubber points are used to
finish and polish and are
especially adaptable when
defining anatomy in the
restoration

30. Carborundum Disc- AKA Jo-dandy disc
 Carborundum discs, also known as Jo-dandy discs and separating
discs, are thin, brittle discs that break easily.
 They are double-sided and are used primarily in the dental
laboratory to cut and finish gold restorations, but they can be used
intraorally as well

31. Types and Functions of Abrasives
 Stones
Used for cutting, polishing, and finishing amalgam, gold,
composite, and porcelain restorations
 Stones are used in the laboratory and are available in many
sizes, shapes, and grits.
used to adjust appliances
 Some stones are considered heatless, and they are used to
polish a restoration without creating frictional heat

32. Types and Functions of Abrasives
Rubber wheels
Used for finishing and
polishing
Rubber points
Used for polishing
Adaptable for defining
anatomy in restoration
© Cengage Learning 2013
© Cengage Learning 2013

33. After using an instrument in the oral cavity, it is
either sterilized or properly disposed.
The bur block comes in a variety of designs and
sometimes can be sterilized with the burs they
hold.

34. Bur blocks

35. Dental Check
What type of bur is used to open the
cavity and remove the carious tooth
structure?
Round