Characteristics of Periodontal Instruments Flashcards
What are the types of periodontal instruments?
Chisel
Hoes
Sickle scaler
Curette
What are the components of the instrument?
Handle
Shank
Working end
Why are shanks bent?
The shanks of most periodontal instruments are bent in 1 or more places to facilitate placement of the working end against the tooth surface
What is the difference between a complex and simple shank?
When instrument is held so that the working end tip or toe is facing you:
Simple shank will appear straight
Complex shape will appear to have a side-to-side bend
What are simple and complex shanks used for?
For anterior teeth = simple
For posterior teeth = complex
Why is a complex shape used for posterior teeth?
Posterior teeth have bulky crowns that are larger in diameter than their roots.
What is the functional shank?
The portion of the shank that allows the working end to be adapted to the tooth surface
When instrument is held with handle facing downwards:
Functional shank begins below the working end and extends to the last bend in the shank nearest to the handle
What is the lower shank?
Portion of the shank nearest to the working end also called the terminal shank.
It is the portion of the functional shank nearest to the working end
How is the working end designed?
Working end is designed for the particular function of the instrument.
To determine an instrument’s use design characteristics of the working end must be recognized.
What are the parts of the working end?
The face which is the part of the working end that hugs the tooth.
The opposite surface is called the back of the working end
What are the lateral surfaces of the working end?
The surfaces on either side of the face are called the lateral surfaces of the working end
What is the cutting edge?
A shape edge formed where the face and the lateral surfaces meet.
Most working ends have 2 cutting edges.
What is the toe of the curet?
The tip of the working end. On some working-ends the working ends meet to form a rounded toe.
What are the thirds of the working-end?
Leading third
Middle third
Heel third
What is the purpose of looking at a cross section of the working end?
The cross-section of a working end determines whether the instrument can be used subgingivally or supragingivally
