1. Dental Handpieces and Accessories
Chapter 35
Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 1

2. Chapter 35 Lesson 35.1
Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 2

3. Learning Objectives Pronounce, define, and spell the Key Terms.
Discuss the historical importance of the dental handpiece.
Describe the low-speed handpiece and its use in dentistry.
Describe the attachments used on the low-speed handpiece.
Describe the high-speed handpiece and its uses.
Review other handpieces used in dentistry.
(Cont’d)
Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 3

4. Learning Objectives
Cont’d)
Identify dental handpieces and correctly attach them to the dental unit.
Describe rotary instruments and how they are used.
List the parts of a bur.
Give the composition, shape, and use of the carbide and diamond burs.
Identify accessories and correctly attach them to the low-speed handpiece.
Identify rotary cutting instruments and correctly attach them to the appropriate dental handpiece or attachment.
Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 4

5. Introduction
Rotary instruments are used to complete different functions in the cutting, polishing, and finishing of tooth structure and the restoration process
What does the term rotary mean? (Rotary is a part or device that rotates around an axis.)
In dentistry, rotary instruments are attached to a handpiece.
Rotary instruments operate at different speeds: high and low.
Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 5

6. The Evolution of Rotary Equipment
1940s
Introduction of rotary instruments
Belt-driven handpiece
Development of diamond cutting burs
1950s
Invention of tungsten carbide
Development of the air-driven turbine handpiece
Rotary instruments were first introduced to complement hand instruments in the cutting, grinding, and polishing procedures of operative dentistry.
Electricity is the power source for rotary instruments.
Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 6

7. Dental Handpiece
The handpiece is the most frequently used piece of machinery in dentistry. It provides power to a rotary instrument that is used to complete the actual cutting or polishing of tooth structure and castings.
Who primarily uses the high-speed handpiece? (Dentist.)
Who primarily uses the low-speed handpiece? (Dentist, dental hygienist, and expanded-function dental assistant.)
Always refer to your state practice act before using a handpiece for treatment or operative procedures.
Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 7

8. Low-Speed Handpiece Design Straight in appearance
Standard length and “shorty”
Speeds range from 10,000 to 30,000 rotations per minute (rpm).
Powers the rotary instrument in both a forward and a backward motion
Also referred to as the straight handpiece because of its design.
The low-speed handpiece is one of the most versatile handpieces in dentistry.
Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 8

9. Fig. 35-2 Low-speed handpiece
Fig Low-speed handpiece. (From Boyd L: Dental instruments: a pocket guide, ed 3, St Louis, 2009, Saunders.)
The straight attachment slides onto the low-speed motor and locks into place.
What is the straight attachment commonly used for? (Laboratory procedures, trimming removable prostheses such as dentures, partial dentures, flippers, and orthodontic retainers.)
Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 9

10. Uses of the Low-Speed Handpiece
Clinical
Removal of soft decay and finishing of cavity preparations
Finishing and polishing of restorations
Coronal polishing and removal of stains
Porcelain adjustments
Root canal treatment
Laboratory
Trimming and contouring of temporary crowns
Trimming and relining of removable partials and dentures
Trimming and contouring of orthodontic appliances
Gloves, protective eyewear, mask, and appropriate garments must be worn during laboratory procedures.
Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 10

11. Low-Speed Attachments
Straight attachments
Long-shank laboratory bur
Prophylaxis angle attachments
Contraangle attachment
Latch-type rotary instruments
Mandrel
What grasp is used with the straight attachment? (Pen or palm grasp.)
What grasp is used with the contraangle attachment? (Pen or modified pen grasp.)
The angled shank of the contraangle attachment provides ergonomic comfort. The operator can maintain proper neutral wrist position more readily during treatment procedures.
Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 11

12. Prophylaxis Angle
Used during polishing procedures to hold the prophylaxis cup and bristle brush
Two types
Plastic disposable “prophy” angle
Metal “prophy” angle
Polishing procedures include prophylaxis, tooth prep before placement of sealant, and amalgam polishing.
What is an advantage of using disposable prophy angles in the dental office? (Infection control. There is no need to clean and process the prophy angle for sterilization after use; simply dispose of the angle.)
What is a disadvantage of using disposable prophy angles in the dental office? (Cost.)
Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 12

13. Fig. 35-5 Disposable prophy cup and brush.
This slide shows disposable prophy angles, one containing a brush and the other containing a rubber cup.
The brush is used to polish occlusal surfaces and lingual surfaces of anterior teeth.
The rubber cup is used to polish smooth tooth surfaces.
Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 13

14. High-Speed Handpiece Design One-piece unit with a slight curve
Operated by air pressure
Operates at speeds as high as 450,000 rpm
Maintains a water-coolant system
Friction-grip locking system for rotary instruments
Fiberoptic lighting
The dentist uses the high-speed handpiece in every restorative procedure.
What is the purpose of the water-coolant system? (The high-speed handpiece generates a significant amount of heat and friction as a result of the high number of revolutions per minute. The water keeps the tooth cool to help avoid injury to the pulp during preparation.)
The fiberoptic light mounted in the head of the handpiece offers additional light to the operator and dental assistant during preparation of the tooth.
Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 14

15. Fig. 35-6 High-speed handpiece
Fig High-speed handpiece. (From Boyd L: Dental instruments: a pocket guide, ed 3, St Louis, 2009, Saunders.)
Unlike the low-speed handpiece, the high-speed handpiece does not have attachments.
The only additional items placed in the high-speed handpiece are rotary instruments.
What are these rotary instruments called? (Dental burs.)
Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 15

16. Uses of the High-Speed Handpiece
Removal of decay
Removal of old or faulty restorations
Reduction of the crown portion of a tooth in preparation for a crown or bridge
Preparation of an outline and retention grooves for a new restoration
Finishing or polishing of a restoration
Sectioning of a tooth during a surgery
The high-speed handpiece rapidly removes diseased or decayed tooth structure.
Often the dentist will refine the tooth preparation with the use of the low-speed handpiece after using the high-speed handpiece.
Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 16

17. Ultrasonic Handpiece Design Attaches to the dental unit
Powered by electricity
Primarily used for prophylaxis appointments
Attachments similar in appearance to scaling instruments
Delivers a pulsating spray of water
The American Dental Association Council on Dental Materials, Instruments, and Equipment evaluates professional scaling devices. Ultrasonic tips are classified as acceptable or provisionally acceptable.
The ultrasonic handpiece uses mechanical radiant energy of water and sound vibrations to create a pulsating effect on a tooth surface.
Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 17

18. Fig. 35-9 Ultrasonic handpiece
Fig Ultrasonic handpiece. (From Boyd L: Dental instruments: a pocket guide, ed 3, St Louis, 2009, Saunders.)
There are three types of ultrasonic scalers: magnetostrictive, piezoelectric, and sonic.
Magnetostrictive: Vibrations range from 24,000 to 42,000 cycles per second.
Piezoelectric: Vibrations range from 29,00 to 50,000 cycles per second.
Sonic (pictured on this slide): Vibrations range from 2500 to 7000 cycles per second.
Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 18

19. Uses of the Ultrasonic Handpiece
Removal of calculus
Removal of stains
Removal of bonding materials from the tooth surface after orthodontic appliances are removed
Removal of cement after orthodontic bands are removed
The attachments for this handpiece are similar in design to hand (manual) scaling instruments.
A specific tip is selected on the basis of the surface and the location of use.
Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 19

20. Laser Handpiece Design
Laser light beam, conducted through a fiberoptic cable, instead of rotary instruments
Resemblance to a standard handpiece
Water-coolant system
Air-coolant system
(Cont’d)
Designed to perform special functions without changes and without damage to the surrounding tissues or materials.
Caution must be used in handling the laser handpiece: Do not sharply bend the fiberoptic cord, do not touch the exposed fiberoptic cable, do not touch the end of the fiberoptic connector, and always keep the connecting parts clean.
Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 20

21. Laser Handpiece Uses Advantages Disadvantage Cauterizing soft tissue
(Cont’d)
Uses
Cauterizing soft tissue
Vaporizing decayed tooth structure
Advantages
Usually painless
Generally no need for anesthesia
Speed of procedure
Disadvantage
Cannot be used on teeth with existing restorations
Lasers are used in dentistry to remove decay from the tooth structure, to cure bonding materials, to whiten tooth teeth, and in periodontal treatment.
Very specific equipment and training are required for the incorporation of laser technology into the dental office.
Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 21

22. Air-Abrasion Handpiece
Design
Small version of a sandblaster
High-pressure delivery of aluminum oxide particles through a small probe
Uses
Preparation of teeth for sealants
Removal of external stains
Class I through class VI preparations
Endodontic access
Crown margins
Preparation of the a tooth surface for the cementation of a cast restoration (e.g., crown or veneer)
(Cont’d)
The air abrasion system was introduced to dentistry in the 1940s. It was originally designed to remove stain and tooth decay.
Considered a patient-friendly approach to restorative treatment
Permits the dentist to remove enamel, dentin, and restorative materials without compromising healthy tooth structure
Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 22

23. Air-Abrasion Handpiece
(Cont’d)
Uses
Preparation of teeth for sealants
Removal of external stains
Class I through class VI preparations
Endodontic access
Crown margins
Preparation of the tooth surface for the cementation of a cast restoration (e.g., a crown or veneer)
One advantage to the use of the air-abrasion handpiece is that there is no need for local anesthesia.
One disadvantage is the possibility of soft-tissue (gingiva) damage if incorrect techniques are used.
Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 23

24. Laboratory Handpiece Design Operates at speeds as high as 20,000 rpm
Uses laboratory burs
Greater torque than that of handpieces used intraorally
What is torque? (A twisting or turning force.)
Increased torque is better suited to the heavier pressure required during grinding and polishing procedures performed outside the mouth.
Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 24

25. Handpiece Maintenance
General considerations
Wear personal protective equipment and follow universal precautions.
Clean debris from the external surface.
Clean the internal components of the handpiece.
Handpiece must be dry before being packaged.
Wrap the handpiece for sterilization.
Sterilize the handpiece.
Wipe the light port on the fiber-optic with an alcohol swab to remove any excess lubricant.
What are the main reasons a handpiece fails or breaks? (Improper cleaning and lubrication.)
Inadequate cleaning of the handpiece before sterilization can result in the collection of debris in the handpiece’s internal parts. Debris creates wear on the handpiece motor and inner movable parts.
Is it possible to lubricate a handpiece too much? (Yes. Too much lubrication can be as damaging as not enough lubrication.)
Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 25

26. Chapter 35 Lesson 35.2
Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 26

27. Learning Objectives Describe rotary instruments and how they are used.
List the parts of a bur.
Give the composition, shape, and use of the carbide and diamond burs
Identify accessories and correctly attach them to the low-speed handpiece.
Identify rotary cutting instruments and correctly attach them to the appropriate dental handpiece or attachment.
Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 27

28. Rotary Cutting Instruments
Three basic parts to a rotary instrument
Shank: Portion that fits into the handpiece.
Straight shank
Latch type shank
Friction grip shank
Neck: Portion of the rotary instrument that connects the shank and the head.
Head: The cutting, polishing, or finishing portion.
Rotary cutting instruments are accessories intended for use with the dental handpiece.
There are hundreds of different types of rotary instruments available in dentistry, and each is designed for a different task or use.
It is important that the dental assistant know the dentist’s preferences.
Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 28

29. Fig. 35-13 Bur parts and types of shanks: A, Long straight lab
Fig Bur parts and types of shanks: A, Long straight lab. B, Latch-type. C, Friction grip. (From Robinson D, Bird D: Essentials of dental assisting, ed 3, Philadelphia, 2001, Saunders.)
Looking at the slide, what part makes up the largest section of the rotary instrument? (Shank.)
The shank length will vary according to the specific function of the bur and the handpiece to which it is attached.
Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 29

30. Dental Burs Rotary instruments with sharp cutting head. Uses
Tooth preparation.
Excavation of decay.
Finishing cavity walls.
Finishing restoration surfaces.
Taking out old fillings.
Finishing crown preparations.
Separating crowns and bridges.
Adjusting and correcting acrylic temporaries.
A dental bur is classified as a “sharp.” Care must be taken when placing the bur on the handpiece and removing the bur after the procedure. Removal of a contaminated bur should be done while wearing heavy utility gloves.
Burs come in a variety of shapes. The shape is commonly referred to as the “contour” or “design.”
Burs are used to enter the tooth structure, remove decay, extend preparations, cut retention grooves, form internal walls of the prep, and provide angles to the wall prep.
Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 30

31. Fig. 35-15 Finishing rotary instruments (Courtesy Miltex, Inc, York, Pennsylvania.)
Finishing rotary burs are similar in appearance to cutting burs except for one distinctive feature. What is that feature? (The number of blades or flutes is increased on the finishing bur.)
The greater the number of cutting surfaces, the greater polishing capability.
The slide pictures the three most common finishing burs: round, tapered and flame-shaped.
Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 31

32. Fig. 35-16 Abrasive materials for rotary instruments
Fig Abrasive materials for rotary instruments. (D, From Boyd L: Dental Instruments: A Pocket Guide, ed 3, St. Louis, 2009, Saunders.)
Numerous abrasive materials are found on these instruments, from very coarse to fine.
Abrasive discs and wheels are attached to a mandrel (a metal shaft), which is then attached to the dental handpiece.
Copyright © 2009, 2006 by Saunders, an imprint of Elsevier Inc. All rights reserved. 32