PRINCIPLES OF INSTRUMENTATION

1. PERIODONTOLOGY SEMINAR
BY MEGHNA JASSI
BDS INTERN

2. PRINCIPLES OF INSTRUMENTATION
• The accurate use of periodontal instruments is fundamental for
appropriate periodontal treatment
• The outcome of periodontal therapy to a great extent depends on
operator’s skill to use the instruments
• In the following slides various aspects of periodontal
instrumentations shall be discussed

3. PRINCIPLES OF PERIODONTAL INSTRUMENTS
• ACCESSIBILITY: POSITION OF PATIENT AND OPERATOR
• VISIBILITY, ILLUMINATION AND RETRACTION
• CONDITION AND SHARPNESS OF INSTRUMENTS
• MAINTAINING A CLEAN FIELD
• INSTRUMENT STABILIZATION
• INSTRUMENT ACTIVATION

4. ACCESSIBILITY
• ACCESSIBILITY facilitates thoroughness of instrumentation
• Position of patient and operator should provide maximum ease of
access
• Inadequate accessibility impedes thorough instrumentation,
prematurely tires the operator and diminishes effectiveness of
clinician

5. Operator position
• Clinician should be seated comfortably on an operating chair so that
clinician’s feet are flat on the floor
• Thighs should be parallel to the floor.
• Back should be straight and head should be in erect position
• Mouth of the patient should be close to the resting elbow of the
clinician

7. Patient position
• Patient position during periodontal treatment is mostly in supine
position but varies with the operator, type of procedure and area of
mouth involved
• Head of the patient is positioned so that the mouth is close to the
resting elbow of the clinician and kept at a slightly higher level (10
degrees) above the rest of the body
• For instrumentation of maxillary arch-
• Patient’s chin should be risen slightly
• For instrumentation of mandibular arch-
• Patient is asked to lower the chin until mandible is parallel to the floor

9. VISIBILITY, ILLUMINATION AND RETRACTION
• The second principle of periodontal instrumentation is good visibility,
illumination and retraction
• The operator should preferably operate the patient with direct vision and
direct illumination
• If working under direct vision is not possible, indirect vision may be
obtained by using mouth mirror for viewing the working area
• If direct illumination is not possible under the dental chair lamp then
mouth mirror can be used for reflecting light to the sight to be operated.
(indirect illumination)
• The light beam of the dental chair lamp should be oriented parallel to the
viewing direction in order to obtain shadow free lighting
• It minimises shadow from hand, teeth, lips and cheek on and around the
working field

10. RETRACTION Can be achieved by
• Use of mouth mirror to deflect the cheek
• Use of finger of non operating hand to retract the cheek (index finger)
• Use of mouth mirror to retract the tongue
• Combination of above methods

11. MAINTAINING A CLEAN FIELD
• Instrumentation can be hampered if the operative field is obscured by
saliva, blood and debris
• Pooling of saliva interferes with visibility during instrumentation and
impedes control because a firm finger rest cannot be established on
wet, slippery tooth surface
• Clean operating field can be obtained with the use of adequate
suction
• Jet of Compressed air and wiping or blotting with gauze piece or
cotton rolls can be used during instrumentation and also helps in
retracting away the gingival margin from tooth surfaced while doing
root planing

12. CONDITIONING AND SHARPNESS OF
INSTRUMENT
• Make sure that instruments are clean, sterile and in good condition
• Working end of the pointed or bladed instrument must be sharp to be
effective
• Sharp instruments enhance tactile sensitivity
• Allow the clinician to work more efficiently by facilitating good
debridement
• Dull instruments may lead to incomplete calculus removal and
unnecessary trauma
• This can happen because excess force usually applies to compensate
for their ineffectiveness

13. INSTRUMENT STABILZATION
• Stability of instrument and hand is the primary requisite for controlled
instrumentation
• Required for-
• Effective instrumentation
• Avoidance of injury to patient or clinician
• FACTORS ENHANCING STABILITY:
• INSTRUMENT GRASP
• FINGER REST

14. INSTRUMENT GRASP
KINDS OF GRASP:
• STANDARD PEN GRASP
• MODIFIED PEN GRASP
• PALM AD THUMB GRASP
KINDS OF FINGER REST:
• CONVENTIONAL
• CROSS ARCH
• OPPOSITE ARCH
• FINGER ON FINGER
EXTRAORAL FULCRUMS:
• PALM UP
• PALM DOWN
• Essential for precise control of movements made during periodontal
instrumentation
• An appropriate instrument grasp minimizes operator fatigue, thus
facilitating good instrumentation

15. STANDARD PEN GRASP
• In this grasp the index finger
and thumb hold the
instrument with side of the
middle finger resting on the
shank
• This grasp provides less tactile
sensitivity and flexibility of
movement during
instrumentation as compared
to the modified pen grasp

16. MODIFIED PEN GRASP
• It is the modification of the
standard pen grasp
• In this grasp the clinician holds the
instrument with pads of the index
and thumb opposite to each other
on the handle closer to the working
end
• The thumb and index finger are not
touching, thereby creating a tripod
effect with the middle finger placed
along the shank of the instrument

17. PALM AND THUMB GRASP
• This grasp is primarily used while
sharpening of the instruments
and during manipulation of air
and water syringes
• This grasp is not recommended
for periodontal instrumentation

18. FINGER REST (FULCRUM)
• It stabilizes the hand and the instrument by providing a firm fulcrum
• Proper finger rest can prevent injury and laceration of gingiva and
surrounding tissues
• Mostly the fourth finger is preferred for finger rest
• Middle finger is kept between the instrument shank and fourth finger

19. INTRAORAL FINGER REST
• CONVENTIONAL FINGER
REST:
• The finger rest is
established on tooth
surface immediately
adjacent to the working
area

20. • CROSS ARCH:
• The finger rest is established on tooth surfaces on the other side of same arch

21. • OPPOSITE ARCH:
• The finger rest is established on tooth surfaces on opposite arch
• For example, while working on the maxillary arch, finer rest is
established on the mandibular arch

22. • FINGER ON FINGER:
• The finger rest is established on the index finger or thumb of the non
operating hand

23. EXTRAORAL FULCRUMS
• Effective for posterior maxillary tooth
• Allow optimal access and angulation while providing adequate
stabilisation
• Finger is placed on patient’s face to provide greatest degree of
stability

24. TYPES OF EXTRAORAL FULCRUMS
• PALM UP:
• The palm fulcrum is established by resting the backs of the middle
finger and fourth finger on the skin overlying the lateral aspect of
mandible on the right side of the face

25. • PLAM DOWN:
• The palm down fulcrum is established by resting the front surfaces of
the middle and fourth finger on skin overlying the lateral aspect of
the mandible on the left side of the face.

26. INSTRUMENT ACTIVATION
• COMPONENTS OF INSTRUMENT ACTIVATION-
• Blade adaptation
• Instrument angulation
• Blade insertion
• Lateral pressure
• Working stoke

28. • ADAPTATION:
• Adaptation refers to the manner in which the working end of the
periodontal instrument is placed against the surface of tooth
• Proper instrument activation is important for the efficient plaque and
calculus removal
• Objective is to made the working end of the instrument conform to
the contour of the tooth surface
• For bladed instrument the lower third of the working end must be in
constant contact with the tooth

29. • BLADE ANGULATION
• It refers to the angle between the face of a bladed instrument and the
tooth surface
• Also called tooth-blade relationship
• Angulation of blade-
• For insertion: 0 degrees
• For calculus removal: 45-90 degrees
• For gingival curettage: >90 degrees

30. • LATERAL PRESSURE:
• It refers to the pressure created when the force is applies against the
surface of tooth with the cutting edge of a bladed instrument
• May be firm (scaling), moderate, or light(root planing)
• DEPENDS ON:
• Nature of calculus
• Purpose (ex. Or initial scaling or for root planing)

31. • STROKES:
• 3 basic type of strokes are:
• EXPLORATORY STROKE
• SCALING STROKE
• ROOT PLANING
• Any of these strokes may be activated by a pull or push motion in
vertical, oblique, or horizontal direction

32. • EXPLORATORY STROKE:
• Light “feeling” stroke
• Used with probes and explorers
• Used to evaluate the dimensions of the pocket
• To detent calculus and irregularities of the tooth surface
• SCALING STROKE:
• Short, powerful pull stroke
• Used with bladed instrument
• Used for the removal of supragingival and subgingival calculus
• ROOT PLANING STROKE:
• Moderate to light pull stroke
• Used for final smoothing and planing of root surface
• Hoes, files, curettes and ultrasonic instruments can be used

33. CONCLUSION
• A goal of instrumentation is to ensure a clean root surface which is
biologically acceptable and is the prime requirement for a healthy
periodontium.
• A clinician can master the technique of instrumentation by strictly
following a practicing the principles of instrumentation.

34. THANKYOU