b. Grasping the Instrument.
(1) Pen grasp and modified pen grasp. Two methods of grasping a scaling
instrument afford control during the scaling stroke (see figure 3-8). The two methods
are the pen grasp and the modified pen grasp in which the thumb, index finger, and
middle finger hold the instrument. In using either grasp, the PDS should hold the
instrument well up on the working edge of the handle, supporting the fingers against the
teeth and using them as fulcrums during the scaling stroke. With the pen grasp, the two
last fingers are used as the fulcrum. Additional control may be gained by bringing
fingers of the other hand into play to help guide or support the instrument.
Figure 3-8. Methods of grasping scaling instruments.
(2) The palm grasp. Another method, the palm grasp, used with the Porte
Polisher, air, water syringe, and other such instruments is accomplished by holding the
instrument with the index, middle, ring, and little finger so it rests in the palm of the
hand. The thumb remains free to stabilize the hand in the patient's mouth.
c. Scaling Motions. A standard scaling instrument is used by sliding it over the
surface of the tooth and calculus to the base of the deposit. Then, the instrument is
pulled toward the occlusal or incisal surface, maintaining firm contact with the tooth
surface and flaking or scraping off calculus ahead of it.
d. Tactile Sense. In working on lingual and proximal surfaces, the PDS often
cannot see well enough to determine the presence and the extent of calculus. In this
case, the PDS must depend upon his tactile sense, which is the feel transmitted to the
fingers by the instrument. The experienced PDS will be able to detect calculus and
remove it even though he cannot see it. An explorer is excellent for determining the
presence of small areas of calculus not detectable by the bulkier scalers and for
checking if there is any calculus left on the teeth (see figure 3-9).