1. Restorative Dental Instruments
Mr. Caputo
Unit #1 Lesson #4

2. Today’s Class
Driving Question: What is the purpose for dental rotary equipment?
Learning Intentions: We will be able to distinguish between high-speed and slow-speed handpieces.
Anchor: Explain why the dental assistant is not allowed to use rotary equipment in a patient’s mouth.

3. Rotary Equipment
Power-driven revolving device used to cut enamel, dentin, or tooth restorative materials
Foot pedal controls power source and amount of compressed air going to the handpiece, which activates and regulates the speed when rotary instruments are used
Rotary instrument group includes several small separate items
high-speed and slow-speed motors
tungsten carbide, stainless steel, or industrial diamond burs

4. Dental Handpieces
Precision-built mechanical device designed for use with rotary instruments such as burs, stones, wheels, and discs
Handpiece tubing systems available with two or four holes
Fiber-optic illumination has been added
Handpieces may be air driven, electric, or powered by compressed gas

5. Parts and Gears of a Dental Handpiece

6. High-Speed Handpieces
Speed ranges from 380,000 rpm to 450,000 rpm
Burs are inserted into a metal friction grip chuck
Water system is used to cool the handpiece
Manufacturer’s instructions must be read
High-speed handpiece heads may be standard or small and may contain a fiber-optic light system for better viewing of the treatment area
Click here for a question to consider

7. Question to Consider
Why is handpiece cleaning and lubrication required?

8. Fiber-Optic Handpiece
Works by light traveling through long, thin fibers of glass or transparent material to head of dental handpiece
Light travels without generating heat
Fiber-optic lighting is useful to help identify and diagnose decay, stains, calculus, faulty restoration margins, and hairline cracks in a tooth
Wet cotton swab should be used with isopropyl alcohol to clean both ends of the handpiece before sterilization

9. High-Speed Handpiece with Fiber Optics
Courtesy KaVo Dental Corporation

10. Slow- or Low-Speed Handpieces
Wide variety of applications in dentistry
Used for removing caries, refining cavity preparations, performing coronal polish, and adjusting restorations
Speed ranges from 5,000 to 80,000 rpm
slow-speed motor
straight or contra-angle attachment
control ring controls the direction of the bur
Manufacturer’s directions must be read for operation, cleaning, lubrication, and sterilization requirements

11. Slow-Speed Handpiece Used for Polishing
Courtesy DENTSPLY Professional

12. Straight Attachments
Nosecone that is connected to motor and may be used independently with long shank burs or linked to other attachments
Contra-angle attachment, prophylaxis angle, or numerous accessory long shank straight burs are fitted into this unit
Can be used outside the oral cavity for cutting and polishing fixed and removable prostheses
Frequent lubrication of the straight attachment keeps internal rotating parts from overheating and prevents buildup of debris

13. Straight Attachment for the Slow-Speed Handpiece
Courtesy DENTSPLY Professional

14. Contra-Angle Angle at the head of the handpiece attachment
Provides better access to difficult areas within oral cavity
Slow-speed contra-angle has a latch-type head into which dental bur or other rotary instrument is placed
Functions to:
remove carious tooth structure
refine cavity preparations
adjust or polish restorations
adjust temporary or permanent prostheses

15. Slow-Speed Contra-Angle
Courtesy Miltex, Inc.

16. Prophylaxis Attachments
Called the prophy-angle or right-angle
90-degree angled shape that connects to straight attachment of the slow-speed handpiece
Used to polish crown surfaces of the teeth
Available as metal, onto which a screw-type rubber cup or brush is attached, or as the recently more popular disposable unit

17. Prophy-Angle
Courtesy Miltex, Inc.

18. Homework #2
Create a venn diagram on Rotary Equipment & Non-Rotary Equipment