Instruments Equipment Flashcards
tools for removal and shaping of tooth structure (2)
hand instruments rotary instruments (handpieces)
Cutting
(excavators, chisels, etc.)
Non-cutting
(amalgam condensers, mirrors,
explorers, probes)
Shank is angled to allow the
cutting edge of the blade
to be within the projected axis of the handle
Double ended instruments
=More
efficient
Single ended instruments=
safer
Bi-bevels: (2)
chisels, ordinary hatchets
Single bevels: (1)
gingival margin trimmers
Gingival Margin Trimmer - Mesial vs Distal
Mesial: To place bevels on the mesial cervical margin of the preparation
Distal: To place bevels on the distal cervical margin of the preparation
Width of blade in tenths of mm
a. 10 indicates
1mm
When necessary, describes angle of
— EDGE to instrument shaft in
clockwise centigrade
CUTTING
Cutting edge angle
◦ measured from a line parallel to the long axis of the instrument
handle in clockwise centrigrades. The angle is expressed as a
percent of 360 degrees
◦ e.g., 85 = 85% of 360 degrees = 306 degrees
is the cutting edge angle always present?
no
cutting instruments- excavators (4)
ordinary hatchets
spoons
hoes
angle formers
Ordinary Hatchets function (2)
◦place retention
◦sharpen line angles
Spoons function
◦remove caries
cutting instruments (7)
chisels enamel hatchets gingival margin trimmers gold knives files cleoid discoid carvers hollenback carvers
Chisels fxn
◦Straight, slightly curved (Wedelstaedt), or bin-angle
chisel- plane walls of prep
Enamel hatchets fxn
◦ cut enamel
Gingival margin trimmers fxn
◦ bevel enamel at gingival
gold knives, files, cleoid-discoid carvers,
Hollenback carvers fxn
◦ cut restorative material
Condensing Instruments (3)
Amalgam condensers, composite and plastic
instruments
Miscellaneous (4)
explorers, probes, mirrors, burnishers
Rotary Instruments use
burs
Term “bur” applies to all rotary cutting instruments that
have
bladed cutting heads
burs fxn (5)
◦Prepare enamel ◦Adjust resin restorations ◦Finish metal and resin restorations ◦Laboratory Work ◦Surgical Removal of Bone (not in operative)
Bur Classification System ◦In the US, arbitrary numerical code for head size and shape ◦ 2= ◦ 57 = ◦ 34 =
◦ 2= 1mm diameter round bur
◦ 57 = 1mm diameter straight fissure bur
◦ 34 = 0.8mm diameter inverted cone bur
Carbide Burs (2)
Carbide Burs
oStiffer and stronger than steel
oMore brittle
Diamond Bur
oDiamond particle size (4)
◦Coarse
◦Medium
◦Fine
◦Finishing burs (even more fine)
Diamond Burs (2)
oHigher hardness
oCutting effectiveness
diamond burs are used for (3)
oIntracoronal and extracoronal tooth preparations
oBevel enamel margins
oEnameloplasty
The — is in the actual handpiece
motor
High-speed handpiece (2)
◦Pneumatic (air-driven)
◦Or Electric
OUR ELECTRIC HANDPIECE CAN BE (2) SPEED
HIGH OR SLOW
Air-water spray for —
cooling
High operating speed
omax — rpm pneumatic
omax — rpm electric
450,000
200,000
Use – pressure
light
Pulpal Precautions (3)
◦Light pressure, air-water
sprays and sharp burs
Soft Tissue Precautions (2)
◦Rubber dam, retract soft
tissue with for example:
mirror & cotton roll
Eye Precautions
◦Safety glasses for operator, assistant and
patient
Ear Precautions
◦Ear plugs, sound absorbing materials used on
walls and floors
Inhalation Precautions
◦Rubber dam, disposable masks
Modified pen grasp (3)
◦Palm away from operator
◦3rd and 4th fingers rest on nearby
tooth
◦Greatest sense of touch
Inverted pen grasp (3)
◦Palm toward operator
◦Used mostly for tooth
preparation from lingual
◦ Usually on anterior teeth
Palm-and-thumb grasp (3)
◦Similar to holding a knife while pairing an apple ◦Power grasp ◦Thumb rests on a nearby tooth to operating site
Modified Palm-and-Thumb Grasp (2)
◦Power plus delicacy
◦Rest thumb on same tooth that is
being prepared or the adjacent tooth
Sharpen at First Sign of —
Dullness
Dull instruments result in: (5)
◦More pressure needed ◦More pain ◦Less control ◦Takes longer ◦Reduces quality
Sharpening Hand Instruments (3)
Stationary stones
Mechanical sharpeners
Handpiece sharpening stones
Sharpening Hand Instruments Basic Principles (7)
◦Clean and sterilize instruments ◦Position blade ◦Use light pressure ◦Use a rest or guide ◦Remove as little metal as possible ◦Lightly hone unbeveled side ◦Re-sterilize
Sterilization
A process by which all forms of microbial life including
bacteria, viruses, spores and fungi are completely
destroyed
Four acceptable methods of sterilization
◦Autoclave
◦Dry heat
◦Chemiclave
◦Ethylene oxide
Follow (4) guidelines
CDC, OSHA, ADA and State Dental Board
Autoclaving (3)
◦Uses steam under pressure
◦250 °F, 15 PSI, 20 mins*
◦Shelves for cassettes
Dry heat (2)
◦Oven-type sterilizer
◦320 °F, 60 to 120 mins*
*Follow manufacturer’s guideline
Chemiclaving (4)
◦ Chemical vapor pressure
◦ Uses chemical solution in a pressurized chamber
◦ 270 °F, 20 to 40 PSI, 20 mins*
◦ Proper ventilation must be installed
Ethylene Oxide (2)
◦ Several hours, below 100°C *
◦ Proper ventilation must be installed
Protecting your instruments
Manufacturers:
◦ Add
rust inhibitors
Protecting your instruments
◦Operators (2)
◦Have instruments free of blood, debris and materials
◦Refer to UMKC SOD Dental Student Clinic Manual
