Parts of an instrument

Parts of an instrument

Copyright 2013 Wolfers Kluwer Health | Lippincott Williams & Wilkins

All Dental hand instruments, be it a dental mirror, probe, scalers or curets are composed of
A. Handle
B. Shank
C. Working-End

Handle
The handle is where one would hold or grasp the instrument and there is usually a serrated to aid in gripping to optimise control of the instrument and reduce fatigue when working in the oral environment.

Shank
The Shank connects the handle to the working end and allows for adaptation of the working end to the tooth surface. It is also used to differentiate between instruments used for posterior (complex) and anterior (simple) teeth.

The shank is composed of the functional shank and lower or terminal shank. 

Functional shank : extends from working end to the bend before the handle

Terminal shank: extends from the working end to the first bend

Shanks can come in a variety of length. 

-Short

-Standard (A)

-Extended (B)

Shanks can also be simple (straight) or complex (bent). 

As a rule of thumb: Simple - Anterior teeth application 

                                         (left)

                                      Complex - Posterior teeth application

                                 (right)

Working End
The working end is what is in contact with the tooth surface and/or the portion of the instrument that does the work as it's name suggest.

The working end has a number of surface depending on the instrument. Most periodontal hand instruments such as sickle scalers and curettes have :

1. Face
2. Back
3. Lateral Surface
4. Cutting edges
5. Tip or Toe

And the working end can be segmented into 3 parts
1) Toe/Tip
2) Middle
3) Heel

You see, the working tip/toe is used for kicking and you want this part to land on that chav's...

Courtesy of my lecturer, Dr C.Gonzales-Marin

The picture below shows the parts of the working ends of these specialised instruments. 

Here's another diagram because we <3 Diagrams! 

Sickle scalers will always have a tip which is sharp _ Curettes have toes which are rounded.
When using these instruments, we work with the first 1-2mm of the instrument.

Another way to differentiate between sickle scalers and curettes is by their cross section.

1. Face the tip/toe of the instrument towards yourself
2. Determine if the cross section is triangular or semi-circular

(If you require graphic aid, it's always wise to determine whether it is shaped like a toblerone chocolate or a kinder bueno)

If it's a toblerone -Sickle scaler

If it's like an inverted kinder bueno- Curette.

• Toblerones Sickle scalers are for Supra-gingival scaling ONLY  
• Kinder Buenos Curettes are for BOTH Supra and Sub-gingival scaling.

My point is that although both instruments have similar structure and looks, they can serve different purpose.