2/15: Instruments Flashcards
What are examples of rotary instruments?
Handpieces
What are examples of cutting instruments?
Excavators, chisels, etc
What are examples of non-cutting instruments?
Condensers, mirrors, explorers, probes
Why is a shank angled?
To allow the cutting edge of the blade to be within the projected axis of the handle
What are the advantages of double ended instruments?
More efficient
What are the advantages of single ended instruments?
Safer
What are the three types of shank angles?
Triple angle
Bin angle
Mon angle
What are the two types of bevels?
Bi-bevels
Single bevels
What are examples of bi-bevels?
Chisels, ordinary hatchets
What are examples of single bevels?
Gingival margin trimmers
What is the function of the mesial side of a hand instrument?
To place bevels on the mesial cervical margin of the preparation
What is the function of the distal side of a hand instrument?
To place bevels on the distal cervical margin of the preparation
Where is the cutting edge angle measured from?
a line parallel to the long axis of the instrument
handle in clockwise centrigrades
What is the cutting edge angle expressed as?
A percent of 360 degrees
e.g., 85 = 85% of 360 degrees = 306 degrees
NOT present all of the time
What are hand instruments that we actually use every time for a prep?
Mirror
Explorer
Perio probe
Clinic only: spoon excavators
What are the functions of explorers?
◦ Feel for caries in clinical situation
◦ Feel for smoothness, sufficient interproximal clearance in lab
What are the functions of perio probe?
Lab only
Measure
What are the advantages of a mirror?
◦ Better visualization
◦ Light reflection
◦ Reminder to not put your hand on patient’s face
What hand instruments do we actually use every time for amalgam?
Mirror
Amalgam carrier
Condenser
Burnisher
Carvers (hollenback (early), cleod/discoid (once amalgam is set up))
Articulating paper holder (primarily in clinic)
What instruments do we actually use every time for composite resin restoration?
Mirror
Composite gun
Condenser
Burnishers
Hollenback carver and/or optrascupt
Curing light
Articulating paper (primarily in clinic)
What hand instruments do we primarily use in a class II restoration?
◦ Shepherd’s hook explorer
◦ Matrix band
Tofflemire + band for amalgam
Sectional (Palodent Plus) for composite
◦ Forceps
What hand instruments do we use in clinic for restorations?
Dycal instrument and spatula in clinic
What are the classification types of hand instruments?
Purpose – ex. scaler, excavator
Position of use – ex. hand condenser
Working end – ex. spoon excavator
Shape of shank – ex. mon-angle chisel
Combination – ex. bin-angle spoon excavator
What are examples of cutting instruments?
◦ Hatchets
- sharpen line angles
- place retention
◦ Spoons
- remove caries
◦ Gingival Margin Trimmers
- Mesial and distal
◦ Gold knives, files, cleoid-discoid carvers, Hollenback carvers (cut restorative material)
◦ Hoes, chisels, angle-formers
◦ Chisels
- Straight, slightly curved (Wedelstaedt), or bin-angle
chisel- plane walls of prep
◦ Enamel hatchets
- cut enamel
◦ Gingival margin trimmers
- bevel enamel at gingival
◦ Others – gold knives, files, cleoid-discoid carvers,
Hollenback carvers
- cut restorative material Boyd
What are examples of condensing instruments
Amalgam condensers, composite and plastic
instruments
What are examples of miscellaneous instruments?
explorers, probes, mirrors, burnishers
What are rotary instruments?
Use burs
Term “bur” applies to all rotary cutting instruments that have bladed cutting heads
What do burs do?
Prepare enamel
◦ Adjust resin restorations
◦ Finish metal and resin restorations
◦ Laboratory Work
◦ Surgical Removal of Bone
◦ (not in operative)
What are the two types of shanks that burs have?
Latch-type
Friction grip
What kind of burs are used for tooth prep?
Carbide burs
Describe the bur classification system
2= 1mm diameter round bur
57 = 1mm diameter straight fissure bur
34 = 0.8mm diameter inverted cone bur
What are carbide burs?
o Stiffer and stronger than steel
o More brittle
What are diamond burs?
oDiamond particle size
◦ Coarse
◦ Medium
◦ Fine
◦ Finishing burs
- even more fine
What are the 4 types of diamond burs?
Flat-End Taper
Flat-End Cylinder
Flame
Wheel
What are diamond burs used for?
o Intracoronal and extracoronal tooth
preparations
o Bevel enamel margins
o Enameloplasty
What are the types of handpieces?
Pneumatic or electric
What are the precautions for handpieces?
Pulpal Precautions
◦ Light pressure, air-water
sprays and sharp burs
Soft Tissue Precautions
◦ Rubber dam, retract soft
tissue with for example:
mirror & cotton roll
What are preventative hazards with cutting instruments?
Eye Precautions
◦ Safety glasses for operator, assistant and
patient
Inhalation Precautions
◦ Rubber dam, disposable masks
Ear Precautions (optional)
◦ Ear plugs, sound absorbing materials used on
walls and floors
Rotary Instruments: Handpieces
What is the modified pen grasp?
◦ Palm away from operator
◦ 3rd and 4th fingers rest on nearby
tooth
◦ Greatest sense of touch
Sturdevant’s et al.
What is the inverted pen grasp?
◦ Palm toward operator
◦ Used mostly for tooth
preparation from lingual
- Usually on anterior teeth
What is the palm and thumb grasp?
◦ Similar to holding a knife while pairing
an apple
◦ Power grasp
◦ Thumb rests on a nearby tooth to
operating site
What is the Modified Palm-and-Thumb Grasp?
◦ Power plus delicacy
◦ Rest thumb on same tooth that is being prepared or the adjacent tooth
What do dull instruments result in?
◦ More pressure needed
◦ More pain
◦ Less control
◦ Takes longer
◦ Reduces quality
What are ways that hand instruments can be sharpened?
Stationary stones
Mechanical sharpeners
Handpiece sharpening stones
What are basic principles for sharpening hand instruments?
◦ 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
What is sterilization?
A process by which all forms of microbial life including
bacteria, viruses, spores and fungi are completely
destroyed
What are 4 acceptable methods of sterilization?
◦ Autoclave
◦ Dry heat
◦ Chemiclave
◦ Ethylene oxide
What is autoclaving sterilization?
◦ Uses steam under pressure
◦ 250 °F, 15 PSI, 20 mins*
◦ Shelves for cassettes
What is dry heat sterilization?
◦ Oven-type sterilizer
◦ 320 °F, 60 to 120 mins*
*Follow manufacturer’s guideline
What is chemiclaving sterilization?
◦ Chemical vapor pressure
◦ Uses chemical solution in a pressurized chamber
◦ 270 °F, 20 to 40 PSI, 20 mins*
◦ Proper ventilation must be installed
What is ethylene oxide sterilization?
◦ Several hours, below 100°C *
◦ Proper ventilation must be installed
