Grasp & Fulcrum Flashcards
Handle:
used for holding the instrument
Shank:
rod-shaped length of metal
located between the handle and
working-end of an instrument
Working-End:
the part of the instrument
that does the work of the instrument
Functional shank:
the part of the shank that allows the
working-end to be adapted to the tooth surface;
begins below the working-end and extends to the last
bend in the shank nearest the handle
Terminal shank:
the portion of the functional shank
nearest to the working-end
Shank Design
• Simple
(3)
• A shank that is bent in one plane (front-to-back)
• Simple shank=straight shank
• Used primarily on anterior teeth
Shank Design
• Complex
(3)
• A shank that has been bent in two planes
(front-to-back and side-to-side)
• Complex shank=angled/curved shank
• Used on posterior teeth
How to determine if
your shank is
simple or complex
• Hold the instrument so that the working-end
toe is facing you
• Instrument A, when viewed from the front
appears to be straight, therefore, simple shank
design
• Instrument B, when viewed from the front
appears to be bent from side-to-side, therefore
this instrument has a complex design
The function of an instrument is
determined, primarily, by the
design of the
working-end.
To determine an instrument’s use,
you must be able to recognize the
design characteristics of the (4)
face,
back, lateral surfaces, and cutting
edges of the working-end.
The Modified
Pen Grasp
• Grasp for
• Allows
• Permits
• Facilitates
holding periodontal instruments
precise control of the working-end
a wide range of movement
good tactile conduction
The Modified Pen
Grasp- continued
• Thumb and index finger hold the
instrument
• Middle finger stabilizes
• Ring finer used to fulcrum (hinge/pivot)
• Thumb is used to roll the instrument
• Fingers maintain contact and work
together to adapt the instrument
• Movement is in the wrist
Finger Placement and Function
Digit (s): Index and Thumb
Placement:
Function:
On the instrument handle
Hold the instrument
Finger Placement and Function
Digit (s): Middle Finger
Placement:
Function:
Rests lightly on the shank
Helps to guide the workingend
Feels vibrations transmitted
from the working-end to the
shank
Finger Placement and Function
Digit (s): Ring Finger
Placement:
Function:
On oral structure; often a tooth surface
Stabilizes the hand for control and strength
Finger Placement and Function
Digit (s): Pinky Finger
Placement:
Function:
Near ring finger, held in a natural, relaxed manner
Has no function in the grasp