Clinic I Lecture 3

Study Notes

Instrument sharpening is the process of restoring a sharp cutting edge to an instrument.
The goal is to reshape the cutting edge to a fine line while removing a minimal amount of material.
A sharpening stone is used as an abrasive to achieve this goal.
A sterile sharpening stone and testing stick are part of a basic clinical setup for a scaling appointment.
All instruments must be handled with care to preserve sharpness and prevent accidental damage to the cutting edges.
Oil lubrication is recommended with certain quarried stones, such as the Arkansas stone.
To maintain the sharpness of a blade, it is important to keep the instrument and stone in a single plane of movement and at the correct angle.
A dull blade presents a flat, shiny surface which can reflect light.
To test the entire length of the blade, the heel (shank end) of the cutting edge is pressed onto the plastic stick first at 90°, then closed to the correct angle for scaling (70°).
The sharp cutting edge engages or grips the plastic as the length of the blade is tested.
The dull cutting edge does not catch without undue pressure and slides easily over the surface of the stick.
To evaluate the sharpness of an instrument, observe the stabilization of both the instrument and stone, the angle at which the stone is being used, and the edge of the blade.
A clean consistent bevel with no particles or “wire edge” remaining is the goal of a newly sharpened instrument.
Curets and scalers can be used to sharpen blades, but the moving stone method is less effective than a method where the stone is stationary and the instrument is moved across it.
The side of the cutting edge formed by the lateral surface is reduced by this method.
Internal angle of the blade at the cutting edge(s) is 70° to 80°.
Visible angle at which the stone will be placed will be 110°.