Lecture 18 Flashcards
Order of instrumentation for calculus removal:
ultrasonics, scalers (Towner/Jacquette, McCalls) then use curettes (Gracey’s)
TF? 30 Jacquette is used to shave off calculus.
F. big chunks
For breaking big chunks of calculus:
U15 Towner/ 30 Jacquette
Best instrument for bicuspids:
McCalls #13/14
Best instrument for molars:
McCalls#17/18
Ultrasonics were first proposed for use for:
cavity prep, early 50’s
When did the ultrasonic become an alternative to hand instrumentation?
60’s
Todays use of ultrasonic:
plaque and calculus
Indications for Ultrasonic Scaling:
calculus, soft tissue debridement (NUG), overhanging resto, excess cement, stain
Is there more or less trauma with ultrasonic scaling?
less
TF? The ultrasonic is a complete substitute for scaling.
F
Benefits to using ultrasonic:
faster, less effort, less discomfort
When to use ultrasonic for soft tissue debridement:
NUG
Types of Powered Scalers:
Sonic, ultrasonic
Hz for Sonic, ultrasonic:
up to 6,000, 20,000-50,000
cycles per s for ultrasonic:
18,000: beyond hearing range
Types of ultrasonic devices:
Magnetostrictive and Piezoelectric
Drives rotor of sonic scalers:
compressed air
cycles per s for sonic scalers:
2.5-7K cycles/s
Tip motion of sonic/ ultrasonic scaler:
elliptical
TF? Sonic scalers req cooling.
T, heat tissues
TF? Sonic scalers are good for removing heavy, hard deposits.
F. Can’t remove
Tip motion of piezoelectric scaler:
linear
What powers the piezoelectric scaler?
piezoelectric transducer
How many sides of piezoelectric scaler are active?
2
Type of current used for piezoelectric scalers:
alternating, AC
TF? The tip of piezoelectric scalers are separate from the transducer.
T
Transduceer is aka:
handpiece
TF? piezoelectric scalers do not produce heat.
F. little heat Linear, Less heat
Adaptation is more critical for this type of scaler:
piezoelectric (WHY?)
What type of scalers are ultrasonics?
magnetostricitve and piezoelectric
How does an ultrasonic work?
oscillating magnetic field (25-30 kHz) across ferromagnetic stack
Which sides of the ultrasonic are active?
all
Is heat generated with an ultrasonic?
yes, water cools and flushes debris
Optimal freq of magnetostrictive, piezoelectric and sonic:
20-40 kHz, 29-50kHz, 2,500 to 7,000 cycles per s
Part that converts energy to vibration:
transducer
transducer for magnetostrictive, piezoelectric and sonic:
metal rod/ stack of metal sheets, ceramic, compressed air
Stroke patter for magnetostrictive, piezoelectric and sonic:
elliptical, linear, elliptical or orbital
Power dispersion on tip of magnetostrictive, piezoelectric and sonic:
all surfaces, lateral surfaces (more), all surfaces
Which 2 types have all tip surfaces active?
magnetostrictive and sonic:
2 MOA’s for ultrasonic scalers:
vibrating tip, cavitation bubbles
disruption of biofilm is aka:
deplaquing
How do cavitation bubbles work?
bubble expands then collapses, -OH and H- radicals formed.
TF? Both -OH and H+ radicals are formed.
F. -OH and H-
Effect of free radicals on biofilm:
kills bacteria in biofilm
Which is more technically demanding, hand scaling or ultrasonic?
hand
When to sharpen ultrasonic tip:
never
__% prefer ultrasonic over hand instruments:
74%, may influence compliance w PM (perio maintenance)
Benefits of hand scaling over ultrasonic:
better subgingivally, no irrigation, no infectious aerosols, good tactile sensitivity, good visibility, hard to damage roots
What type of therapy is irrigation considered?
chemotherapy (check)
Possible damage that may occur to roots w ultraonic scaler:
root gouging
How many positions does the foot pedal of the ultrasonic provide?
2, half/ fully depressed
Steps to setting up ultrasonic:
Convenient location, water, flush tubing, fill with water, lubricate O-ring, seat insert in handpiece, adjust water spray
Dental unit waterlines bc infected w:
microorganisms
Options to control contamination:
Self-contained reservoirs, point-of-use filters, flushing of water tubing
How long to flush ultrasonic handpiece:
2 min at start of each day, 30s bw pts
Why add water to hand piece before inserting tip:
expel bubbles from hand piece, prevent overheating
Bubbles in an ultrasonic hand piece can cause:
over heating
Lubricate the O-ring with:
water
Do you need to twist the ultrasonic tip into place?
yes
Where to adjust water spray:
unit or handpiece
This passes thru instrument tip:
water coolant
Adjust water flow at this power setting:
lowest
More aerosol for __, less for ___.
moderate-heavy calculus, light calculus, plaque
The ultrasonic is __ _ __ (3 words) when using for light debris and deplaquing (plaque, not calculus!)
“out of phase”
When to readjust water spray:
When changing power level or tips
Why wrap cord of handpiece around pinky or arm?
weighs down, may cause handpiece to twist during instrumentation
Power =
freq X amp
Freq =
number of vibrations
Amplitude =
length of vibration
When to use low power, low frequency, low amplitude
light calculus, staining, deplaquing
When to use med power, med frequency, med amplitude
mod to heavy calculus, stain
Power rarely goes above:
medium
most comfortable power range zone:
Blue zone
Fully depressed foot control
Boost mode
% increased power w fully depressed foot control:
25%
1/2 depressed pedal:
tip activated, irrigating water flows
How to get to “boost” mode:
fully depress pedal
Type of strokes dentists should use for ultrasonic:
short, light
What will happen if ultrasonic is used at 90d angle to tooth?
gouging
How to reduce aerosol effect of ultrasonic:
high speed evacuation
This happens with heavy pressure of the ultrasonic:
oscillation dampening
9 groupings of ultrasonic tips:
scaling, resto, maintenance, perio, V-tip restorative, V-tip endo, endo, retrograde endo, and prosthetics
All perio tips for ultrasonics are used:
subgingivally
TF? Heavy deposits require more tactile sense.
F. less
There are special tips for:
subgingival, furcations, implants
Thin tips for ultrasonics are used for:
light deposits
When to use standard diameter insert:
general debridement
Tip to access subgingival area:
subgingival insert
2 types of irrigation with ultrasonic:
External, Internal (Dr. Culotta: external, align both tips, internal seems less likely to break)
Use implant tips for:
Debridement of implants, cosmetic restorations
Are the ultrasonic tips and/or point adapted to tooth surface?
No
Covers for ultrasonic for implants:
carbon composite or plastic
Parts of ultrasonic that should not be directly adapted to tooth:
point or face
Parts of ultrasonic that should be directly adapted to tooth:
back, lateral surfaces
Surfaces of ultrasonic for deposit removal:
back and lateral
Surface(s) most effective for tenacious calculus:
lateral
Highest to lowest power dispersion of magnetostrictive insert tip:
point, face/ concave, back/ convex, lateral
When to use ultrasonic tip:
fracture large calculus ledges, rings
TF? Brief contact of tip to sound enamel is probably harmful.
F. probably not
Active portion of ultrasonic tip:
last 2-3mm of the back or lateral surface
tip-to-tooth surface angulation should be close to:
0d
Lateral surfaces of an ultrasonic is adapted in a similar fashion to a:
curet working-end
Lateral surface adapted to the facial surface in a similar manner to a:
periodontal probe
How does the approach to calculus removal differ bw ultrasonic and hand instruments?
top-down vs pocket base to CEJ
Work in this direction in a pocket with an ultrasonic:
apical
Two techniques for orientation of tip to tooth:
Transverse / vertical tip orientation
vertical tip orientation:
back or lateral surface positioned similar to probe
transverse tip orientation:
back or lateral surface positioned similar to curet, R angle to long axis
Powered instrument tips break up heavy calculus deposits by creating:
microfractures
When to leave the tip of ultrasonic in one spot for a few seconds:
never, keep it moving
Motion/ stroke used against large calculus deposits:
tapping
Motion/ stroke used on light calculus deposits and deplaquing:
sweeping
How to make sure all calculus is removed with ultrasonic:
Overlapping, multidirectional strokes
Most common mistake in using ultrasonic:
heavy or moderate pressure, stops vibrations
Standard diameter tips are used for:
med to heavy calculus, coronal surface, subg deposits easily accessed
HVE stands for:
high volume evacuation
Magnetostrictive scalers operate at either:
25kHz or 30kHz
How to reduce bacteria in aerosols while using ultrasonic:
Pre-procedural rinse (chlorhexidine) (ask, does this also reduce bacteremia?)
Is hearing protection recommended during US use?
yes
How much of a difference in effectiveness are high and medium power settings for US?
NO DIFFERENCE
Too little water will lead to:
pulp damage
Difference in calculus removal between 25kHz and 30kHz scalers:
No substantial difference
Main difference bw 25kHz and 30kHz units:
less noise
Are the inserts bw 25 and 30kHz interchangeable?
No
Will a 25kHz vibrate a 30kHz insert?
no
Occupational risks with ultrasonic scalers:
Neurological, musculoskeletal, tinnitus (ringing/ buzzing in ear)
Possible neurological, musculoskeletal problems assoc w vibrating devices:
Loss of strength, tactile sense, sensory perception, hearing
Patient contraindications for US:
Unshielded (define) cardiac pacemakers / defibrillators (except piezoelectric, no electric field), communicable diseases (TB), at risk of respiratory disease, primary/ newly erupted perm teeth, large pulp chambers, difficulty swallowing, prone to gagging
Pts at risk of respiratory disease:
immunosuppressed, chronic pulmonary disease, asthma
How long can aerosols stay in the air after US use?
many hours
Pts prone to difficulty swallowing or prone to gagging:
MS, ALS, muscular dystrophy, Parkinson’s, paralysis (MMAPP)
Tooth Contraindications for US:
demineralization, sensitivity, implants (wo special tip), restorative materials (ask)
1 mm tip wear = __% loss calculus removal ability. (Markings on tips?)
25
2 mm tip wear = __% loss calculus removal ability.
50
When should US tips be discarded?
2mm of wear
power is localized here in US insert:
last 2 to 4 mm of tip
Slim-Diameter straight tip work well on these roots:
anterior, straight roots, shallow pockets of posteriors
Part of curved slim tips that adapts best:
Back of working-end
Curved slim tip w ball end, ideal for use in:
furcation area
technique to contain water during US use:
cupping
Pt pos during US use:
supine, side, down
Is there a sig. difference between manual and ultrasonic?
No
To clean furcations:
Roll ball of working-end across furcation roof
Should the US be on or off when locating the furcation?
off
Stroke type to use to locate furcation:
oblique
What fits into a furcation better, ball tip or curette?
ball tip
To get best tactile sense with US:
release pedal
When to use transverse technique:
above or slightly below gingival margin
When to use vertical technique:
below gingival margin
Tip for posterior tooth surfaces more than 4 mm apical to CEJ:
curved
Tip for anterior teeth even in deep pockets, posterior tooth surfaces 4 mm or less apical to CEJ:
straight
