Week 9 Instruments and Equipment Flashcards
what are examples of non cutting hand instruments
amalgam condensers, mirrors, explorers, probes
what are examples of cutting hand instruments
excavators, chisels
shank is angled to allow ____
the cutting edge of the blade to be within the projected axis of the handle
- allows force on blade without rotation
double ended instruements are ___. single ended instruments are ____.
more efficient; safer.
what are the shank angles
triple angle
- bin angle
- mon angle
which of the shank angles are contra angles
triple angle and bin angle
what are exampls of bi- bevels
chisels, ordinary hatchets
what are examples of single bevels
gingival margin trimmers
what are the two types of gingival margin trimmers
distal and mesial
what is the cutting edge angle measured from
a line parallel to the long axis of the instrument handle in clockwise centrigrades. angle is expressed as a percent of 260 degrees
- not present all of the time
what hands instruments do we use all the time in restorations
mirros
-condenser
- burnisher
- amalgam carrier
-carvers
- optrasculpt
- articulating paper holder
what does the term bur refer to
all rotary cutting instruments that have bladed cutting heads
what are burs used for
prepare enamel
- adjust resin restorations
-finish metal and resin restorations
- lab work
- surgical removal of bone
what are the different bur types
latch type shank and friction grip shank
what are the carbide burs for tooth prep
-round
- inverted cone
- pear shaped
- straight fissure
-tapered fissure
what shape is the 330
pear shaped
what shape is the 169
inverted cone
what shape is 56
straight fissure
what shape is the 245
pear shaped
what is the arbitrary numerical code for head size and shape of burs
- 2: 1 mm diameter round bur
- 57: 1 mm diameter straight fissure bur
- 34: 0.8 mm diameter inverted cone bur
describe carbide burs
stiffer and stronger than steels
- more brittle
what are the diamond particle sizes
-coarse
-medium
fine
- finishing burs
- even more fine
what are the types of diamond burs
-flat end taper
- flat end cylinder
-flame
- wheel
describe diamond burs and their use
- higher hardness
-cutting effectiveness - used for: intracoronal and extracoronal tooth preps, bevel enamel margins, enameloplasty
what are the parts of a handpiece
head
shank
connecting end
- swivel connector
what is in the handpiece
the motor not the swivel
what is the max rpm on pneumatic handpiece and electric
pneumatic: 450,000
electric: 200,000
what is the rpm on the slow speed handpiece
20,000-40,000
what are the precautions for potential hazards with cutting instruments
-pulplal precautions: light pressure, air water sprays and sharp burs
- soft tissue precautions: rubber dam, retract soft tissue
how can we prevent hazards with cutting instruments
- eye precautions: safety glasses for operator, assistant and patient
- inhalation precautions: rubber dam, disposable masks
- ear precautions: ear plugs, sound absorbing materials used on walls and floors
describe the modified pen grasp
- palm away from operator
- 3rd and 4th fingers rest on nearby tooth
- greatest sense of touch
describe the inverted pen grasp
- palm towards operator
- used mostly for tooth preparation from lingual usually on anterior teeth
describe the palm and thumb grasp
- similar to holding a knife when pairing an apple
- power grasp
- thumb rests on a nearby tooth to operating site
describe 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 sharpening hand instruments
- stationary stones
- mechanical sharpeners
-handpiece sharpening stones
what are the basic principles to sharpening hand instruments
-clean and sterilize instruments
- position blade
-use light pressure
- use a rest or guide
-remvove 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 the 4 acceptable methods of sterilization
-autoclave
- dry heat
- chemiclave
- ethylene oxide
describe autoclaving
-uses steam under pressure
- 250 degree F, 15 PSI, 20 minutes
-shelves for cassettes
describe dry heat
-oven type sterilizer
- 320 degrees F, 60-120 mins
describe chemiclaving
- chemical vapor pressure
- uses chemical solution in a pressurized chamber
- 270 degrees F, 20-40 PSI, 20 mins
- proper ventilation must be installed
describe ethylene oxide
-several hours below 100 decrees C
- proper ventilation must be installed
how can manufacturers protect instruments
add rust inhibitors
how can operators protect instruments
have instruments free of blood, debris and materials
what is a big drawback of the original palodent
doesnt allow wedging
what is the theory behind clamping with the original palodent
causes slight separation of the teeth and assists in getting better contact on the restoration
does the palodent plus allow for wedge placement
yes
when is the T band used
in pedodontics
what matrix system is used for a severely damaged tooth
the automatrix system and the copper band
what are the limitations to the automatrix system
- must be held in place by your non dominant hand when there are no undercuts on the side walls of the tooth
-doesnt work well when tooth defects go far apically
how do you remove the copper band after packing amalgam
cut with a 169 bur
what are the limitations of the copper band matrix
- because of stiffness and thickness of copper band it is useful primarily on teeth already prepared for crowns. true contact with neighboring teeth is nearly impossible to obtain with a copper band matrix
- must be stabilized with non dominant hand while packing amalgam or when cutting band for removal
- copper bands are subject to strain hardening if you work the metal very much . if this happens hold over flame until it glows red and quench in water this is called stress relief annealing which softens the metal against so the copper does not resist attempts to shape it
what is the purpose of water
for cooling so you dont burn the tooth
