Dental Handpiece Rotary Cutting Instruments Classification

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What is the role of the face of the blade in a bur?

It is an imaginary line tangent to the lip of the blade and 1 to radius

It meets the cut structure as the leading side (correct)

It is an imaginary line passing through the tip of the blade and the center of rotation

It follows the back of the blade as the trailing side

What is the significance of the radius of the blade in a bur?

It is an imaginary line passing through the tip of the blade and the center of rotation (correct)

It provides better cutting efficiency but on expense of the bulk of the blade

It is an imaginary line tangent to the lip of the blade and 1 to radius

It is the angle between the face and back of the blade

What does positive rake angle indicate in a bur?

The radial line is ahead of the face of the blade, providing better cutting efficiency (correct)

The angle between face and back of the blade

The radial line is overlying the face of the blade, resulting in moderate cutting efficiency

The radial line trails the face of the blade, producing minimal cutting efficiency

What is eccentricity or run-out in relation to a dental instrument?

The maximum displacement of the periphery of working point from its central axis Signup and view all the answers

What factor enhances cutting efficiency and acts as a lubricant during cavity preparation?

Coolant Signup and view all the answers

What is one possible adverse effect associated with increased speed of rotary instruments?

Reduced cutting efficiency Signup and view all the answers

What is one reason for utilizing carbide burs with regular and ultra-high speed handpieces?

To resist melting and bending, thus showing high cutting efficiency with less heat production Signup and view all the answers

In dental bur classification, what does 'smart prep burs' refer to?

A method based on constructing a mechanical device for dentin caries removal using a material much softer than carbide steel Signup and view all the answers

What does frictional grip attachment for burs specifically indicate?

Attachment used with ultra-speed handpiece Signup and view all the answers

What are steel burs primarily used with due to potential damage at higher speeds?

Regular speed only Signup and view all the answers

What type of burs are used for lateral extension of cavity walls by undermining enamel?

Inverted cone burs Signup and view all the answers

What modification has been made to reduce unduly rough surfaces produced by cross-cuts on fissure burs at high speeds?

Reduced use of cross-cuts since they are no longer needed at high speeds Signup and view all the answers

What is the rotational speed of an instrument measured in?

Rotations per minute Signup and view all the answers

Which speed range is generally recognized for rotary cutting instruments?

Regular, medium, and high Signup and view all the answers

What type of speed range is used for tooth preparation and removing old restorations?

High or ultra high speeds Signup and view all the answers

Why is the low-speed range used for cleaning teeth, caries excavation, and finishing and polishing procedures?

It is ineffective and time-consuming Signup and view all the answers

What is a disadvantage of using low-speed cutting?

It requires heavy force of application Signup and view all the answers

Why are brittle carbide burs easily broken at low speeds?

Low-speed cutting is a traumatic procedure Signup and view all the answers

What are the advantages of using high or ultra high speeds for tooth preparation?

Remove tooth structure with less pressure, vibration, and heat generation Signup and view all the answers

Why is the number of cutting instruments used reduced when using higher speeds?

The smaller sizes are more universal in application Signup and view all the answers

What is a benefit of using high or ultra high speeds for tooth preparation in terms of instrument longevity?

Instruments last longer Signup and view all the answers

Why are patients less apprehensive when higher speeds are used for tooth preparation?

Less vibration and decreased operating time Signup and view all the answers