Dental Instruments and Powered Rotary Devices

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Questions and Answers

What is the primary purpose of surface treatment such as sand blasting in dental procedures?

To polish the tooth structure

To remove all traces of enamel

To encourage tooth decay

To prepare the surface for cementation (correct)

Which type of rotary tool primarily works by an abrading process?

Bladed bur

Friction grip shank

Abrasive stones (correct)

Dental rotary bur

Which type of shank fits into a low-speed handpiece for dental tools?

Threaded shank

Short latch shank (correct)

Friction grip shank

Long shank

How are rotary instruments classified according to the material of construction?

Carbon steel, tungsten carbide, and diamond tips Signup and view all the answers

What characteristic identifies a crosscut carbide bur?

It is defined by its flute design Signup and view all the answers

What is the primary source of power for powered rotary cutting instruments in dentistry?

Electric motor Signup and view all the answers

Which of the following is NOT a type of hand cutting instrument?

Laser Signup and view all the answers

What component of a hand cutting instrument is specifically designed for its cutting function?

Blade/Working end/Cutting Edge Signup and view all the answers

How is rotary speed categorized for powered rotary cutting instruments?

Low, medium, high speed ranges Signup and view all the answers

Which type of hand cutting instrument would you use to smooth the enamel margin and place retention grooves?

Chisel Signup and view all the answers

What classification aspect of dental instruments involves the angles present in the shank?

Number of angles in the shank Signup and view all the answers

Which of the following powered rotary cutting instruments typically provides more control over speed during preparation?

Electric motor driven instruments Signup and view all the answers

What material is commonly used for manufacturing hand cutting instruments?

Carbon Steel Signup and view all the answers

What is a primary disadvantage of using a low speed handpiece?

It is ineffective Signup and view all the answers

Which of the following is an advantage of high speed handpieces?

They remove tooth structure faster Signup and view all the answers

What is the primary function of a laser handpiece in dental procedures?

To cauterize soft tissue and vaporize decayed structures Signup and view all the answers

Which rotary speed range does a contra-angle handpiece typically fall under?

High speed/ultrahigh Signup and view all the answers

What feature of the air abrasion handpiece distinguishes it from ordinary polishing methods?

It delivers particles through high-pressure air Signup and view all the answers

What indicates that a high speed handpiece is more effective for certain dental procedures?

It generates less vibration and operates faster Signup and view all the answers

Which type of laser handpiece is most commonly used during soft tissue procedures?

CO2 laser Signup and view all the answers

Why can the laser handpiece not be used on teeth with existing restorations?

Restorations are harder and may not respond to the laser Signup and view all the answers

Study Notes

Instruments (Part 2)

Classified by force/power: hand cutting, powered rotary, laser, air abrasion
Hand cutting instruments are made from: carbon steel, stainless steel, carbide steel, other nickel, cobalt, and chromium alloys.
Instrument design includes: handle, shank, blade/working end/cutting edge (can also be nib/face/non-cutting end/point if not cutting).
Examples of instruments include excavators, hatchets, hoes, chisels, gingival margin trimmers, used for various dental procedures.

Powered Rotary Cutting Instruments

Parts/devices that rotate around an axis
Used in dentistry, attached to a handpiece
Power source: electric motor (separate or part of unit), stable steady speed, high torque, high cutting efficiency, controlled speed, more accurate smooth preparation.
Also: compressed air (air turbine), pneumatic, dentist controls speed

Rotary Speed Ranges

Low speed (below 12,000 rpm)
Medium speed (12,000-200,000 rpm)
High speed (above 200,000 rpm)

Handpieces

Device holding the cutting instrument, transmits power.
Rotary speed range: low, medium, high (speeds given for each).
Handpiece shapes: straight, contra-angle.
Low speed may be a latch type
Low speed disadvantages: Ineffective, time-consuming, requires heavy force/vibration.
Low speed indications: Initial grooves and holes, teeth cleaning/polishing, deep caries excavation, finishing/polishing restorations.
High speed advantages: Faster removal, less vibration, more operator control, better patient comfort, longer-lasting instruments.
High speed indications: Cavity preparation, removal of old restorations, crown preparation for fixed prostheses.

Laser Handpieces

Uses high intensity light instead of rotary
Design: fiber-optic cable, water-coolant system, similar to standard handpieces, power determines beam effect.
Use: cauterize soft tissue, vaporize decayed tooth structure
Disadvantage: not used on teeth with existing restorations (e.g., amalgam).

Air Abrasion Handpieces

Small version of a sandblaster, delivery of aluminum oxide particles
Design: small probe, high-pressure
Uses: preparing teeth for sealants, removing stains, surface treatment of crowns/veneers.

Cutting Tools

Rotary tools (classified as burs or abrasives)
Burs: cut; Abrasives: grind.
Design includes: Shank (fits into handpiece), Neck (connects head/shank), Head (cutting edge).
Head Classification: cutting style, material (carbon steel, tungsten carbide, diamond, etc.), size.

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Description

Explore the different classifications of dental instruments and their design features in this quiz. Delve into hand cutting and powered rotary cutting instruments, their uses, and the technology behind them. Test your knowledge on speed ranges and component characteristics relevant to dental procedures.