INSTRUMENT STABILIZATION Dr.linda Maher

The two factors of major importance in providing stability are: . Stability of the instrument and the hand is the primary requisite for controlled instrumentation. Stability and control are essential for effective instrumentation and avoidance of injury to the patient or clinician The two factors of major importance in providing stability are: 1\the instrument grasp. 2\the finger rest.

INSTRUMENT GRASP There are four grasps used with the hand instruments: THESE ARE THE MANNER OF HOLDING THE INSTRUMENTS. There are four grasps used with the hand instruments: 1. Modified pen. 2. Inverted pen. 3. Palm and thumb. 4. Modified palm and thumb

FINGER IDENTIFICATION FOR THE GRASP The index finger and thumb hold the instrument handle. The middle finger rests on the instrument shank. The ring finger advances ahead of the other fingers to act as a support for the hand and instrument

1\The Modified Pen Grasp. Similar to that used in holding a pen except that the middle finger contacts the shank of the instrument The modified pen grasp is the recommended grasp for holding instrument. Advantages of modified pen grasp: 1\ allows good control of the working-end 2\permits a Wide range of movement 3\facilitates good Tactile conduction

2\Inverted pen grasp The hand is rotated so that the palm faces more toward the operator. Used in lingual and labial surfaces of anterior teeth.

3\PALM AND THUMB GRASP: Use for holding hand piece While cutting incisal retention For class III cavity preparation.  

4\MODIFIED PALM AND THUMB GRASP The same as in palm and thumb grasp but the thumb is rested on the tooth being prepared Used in the upper arch

FINGER REST The finger rest serves to stabilize the hand and the instrument. The forth finger(ring finger)is preferred for the finger rest Finger rest classified into: 1\intraoral finger rest 2\extra oral fulcrum

1\INTRA ORAL FINGER REST: 1\CONVENTIONAL Finger rest is established on tooth surface immediately adjacent to the working area

2\CROSS ARCH: The finger rest is established on tooth surfaces on the other side of the same arch

3\OPPOSITE ARCH Finger rest is established on tooth surfaces on the opposite arch(e.g. Mandibular arch finger rest for instrumentation on the maxillary arch)

4\FINGER ON FINGER: The finger rest is established on the index finger or thumb of the non-operating hand

2\EXTRA ORAL FULCRUM USED FOR: TWO TYPES: Some aspects of maxillary posterior teeth EXTRA ORAL FULCRUM ARE NOT FINGER REST because the tips or pads of the fingers are not used TWO TYPES: 1\palm up 2\palm down

1\PALM UP Resting the back of the middle and forth fingers on the skin overlying the lateral aspect of the mandible on the right side

2\PALM DOWN Resting the front surfaces of the middle and fourth fingers on the skin overlying the lateral aspect of the mandible on the left side

. Thank you