1. Prof. Faten M Kamel Bchd, Msc, Phd.
INSTRUMENTS
Prof. Faten M Kamel
Bchd, Msc, Phd.

2. Removal & shaping of tooth structure are essential aspects of restorative dentistry. Initially, it was a difficult task that was accomplished entirely by hand instruments. Rotary & powered cutting equipment was a major breakthrough in dentistry.

3. Instruments
Hand cutting
Rotary cutting

4. General classification of instruments
Instruments used for removal of tooth structure and restoration
Instruments used for manipulation and packing or condensation of restoration
Instruments used for finishing and polishing
Instruments used for isolation
Instruments used for miscellaneous purposes

5. Instrument design Most hand instruments are composed of three parts:
1.      Shaft
- it’s the part grasped by the operator hand
- available in various sizes & shapes
2.      Shank
- connect the shaft to the working end of the instrument
- may be straight, single, double or triple angled
3.      Blade/nib
For many non cutting instruments, the part corresponding to the blade is termed Nib. Some instruments have a blade on both ends of the handle & termed Double ended instruments.

6. The cutting edge
working part of the instrument, usually in the form of bevel with different shapes
The blade angle
angle between the long axis of the blade and the long axis of the shaft
The cutting edge angle
angle between the margin of the cutting edge and the long axis of the shaft

7. Hand instruments are named according to:
Purpose of use
Position of use
Form of its working
Angles on the shank

8. Instrument formula
First number: width of the blade in tenth of mm
Second number: length of the blade in mm
Third number: angle between the blade and long axis of shaft in centigrade
Fourth number: edge of the blade is at an angle other than 90º to the blade. It is placed next to the blade width