Instrument Sharpening dentistry perio.pptx

Instrument sharpening in periodontal dentistry

1. Instrument Sharpening Dr. Masoud Amiri Moghaddam Assistant Professor of Periodontics Gilan University of Medical Science

2. A sharp instrument cuts more precisely and quickly than a dull instrument Dull instrument must be held more firmly and pressed harder than a sharp one  r educes tactile sensitivity and increases instrument slip

3. The cutting edges of a curette, for example, are formed where the face of the blade meets the lateral surfaces dull instrument is held under a light, the rounded surface of its cutting edge reflects light back to the observer. It appears as a bright line running the length of the cutting edge When a sharp instrument is held under a light, no bright line can be observed acrylic rod known as a “sharpening test stick.”

4. Objective of Sharpening Restore the fine, thin, linear cutting edge of the instrument A technique is acceptable if it produces a sharp cutting edge without unduly wearing the instrument or altering its original design

5. Sharpening Stones Natural mineral deposits or produced artificial Abrasive crystals that are harder than the metal of the instrument to be sharpened Coarse stones or Finer stones ? India and Arkansas oilstones are examples of natural abrasive stones Carborundum , ruby, and ceramic stones are synthetically produced

6. Mounted Rotary Stones Unmounted Stones

7. Principles of Sharpening Establish the proper angle between the sharpening stone and the surface of the instrument Maintain a stable, firm grasp of both the instrument and the sharpening stone Avoid excessive pressure Avoid the formation of a “wire edge”  by finishing with a down stroke toward the cutting edge Lubricate the stone during sharpening Oil should be used for natural stones and water for synthetic stones

8. Sharpening Individual Instruments Universal Currete  angle between the face of the blade and the lateral surface of any curette is 70 to 80 degrees

9. Sharpening the Lateral Surface The angle between the face of the blade and the surface of the stone will be 100 to 110 degrees Short, up-and-down strokes. Sharpen the entire blade from shank end to toe. Toe  be sure to sharpen around it to preserve its rounded form Finish each section with a down stroke into or toward the cutting edge

10. Sharpening the Face of the Blade Handheld cylindrical or cone-shaped stone back and forth across the face of the blade Sharpening the face of the blade narrows the working end from face to back. This weakens the blade and makes it likely to bend or break while in use Sharpening the face of the blade with a handheld stone using a back-and-forth motion produces a wire edge that interferes with the sharpness of the blade

11. Area- Specifc ( Gracey ) Curettes  A ngle of 70 to 80 degrees between the face and lateral surface of its blade Only the larger, outer cutting edge is used for scaling and root planing  Only one cutting edge needs to be sharpened Apply the stone to the lateral surface so that the angle between the face of the blade and the stone is 100 to 110 degrees short, up-and-down strokes Finish with a down stroke.

12. Thanks for Your Attention