Modern Dental Assisting Chapter 35

The low speed motor rotates how many times per minute?

Ranges from 10,000-30,000 rpms

What three attachments can fit onto the low speed motor?

Straight handpiece

Contra-Angle handpiece

Prohpy Angle handpiece

The straight attachment for the low speed motor is commonly used for which procedures?

Trimming and contouring of custom trays, temporary and provisional appliances, removable partials and dentures, and orthodontic appliances

What does the contra-angle use to attach rotary instruments, files, and mandrels?

Latch type locking system

What procedures would the contra-angle handpiece be used for?

Removal of soft decay, cavity prep, coronal polishing, porcelain adjustments, root canal treatment

Prophylaxis Angle

Used during polishing procedures to hold the prophy cup and the bristle brush

What procedures is the high speed handpiece used for?

Used for the removal of soft decay, removal of an old or faulty restoration, crown reduction, prep of outline and retention grooves, finishing and polishing of restorations, sectioning a tooth during surgery

What is the water coolant system used for with the high speed handpiece?

The tooth ad bur are constantly sprayed with water to:

1. Reduce frictional heat on the tooth that can damage the pulp

2. Remove debris

3. Allow the operator better visability

High speed handpieces operate with a locking system for burs called:

friction-grip

The head of the high speed hand piece is equipped with what important piece?

A fiber-optic light, used to deliver the proper amount of light directly onto the operating site

Ultrasonic Handpiece

A mechanical radiant energy of water and sound vibrations are used to create a pulsating effect on the tooth's surface.

What is the ultrasonic handpiece used for?

The scaling and root planing procedure, removal of bonding appliances left over from orthodontic appliances

Laser Handpiece

Uses a beam of laser light to cauterize soft tissue or vaporize decayed tooth structure, is painless, and does not require anesthetic

Air Abrasion Handpiece

Allows high pressure delivery of aluminum oxide particles through a small probe, similar to a sandblaster, to remove stains and tooth decay.

Laboratory Handpiece

Designed for the dental laboratory, provides greater torque

Handpiece Maintenance

Excessive lubrication, inadequate lubrication, debris causing wear, inappropriate cleaning solutions cause damage

The dental handpiece is considered a

semi-critical instrument

Straight Shank

Low speed handpiece

Latch Type Shank

Mechanically locks into the contra-angle attachment, low speed handpiece

Friction-Grip Shank

short and smooth, has no retention grooves, high-speed handpiece

Straight fissure plain cut

Initial entry to tooth

Forms internal walls

Straight fissure cross cut

forms internal walls

Tapered fissure plain cut

provides angles to walls

Tapered fissure cross cut

Provides angles to walls of prepared tooth

Pear shaped bur

initial entry, extends prep

End cutting bur

initial entry, shoulder for crown prep

Round Bur

Initial entry, extends prep, retention, removes decay

Inverted Cone Bur

Removes decay, retention grooves

Diamond Rotary Instruments

Cutting ability shortens preparation time and increases productivity

What shapes of diamond burs are there?

Round, flat end taper, flame, wheel

Finishing rotary instruments differ from cutting burs because they have

more flutes

The greater number of flutes, the greater

the polishing or finishing capability of the bur

Flute

blades on the working end of a finishing rotary bur

How does dental handpiece work

Can be air driven or electric. Attached to hose and you press rheostat to make it move.

What does all the work on the handpiece

The turbine