Dental calculus and ultrasonic scalers Flashcards
what causes periodontal disease?
plaque bacteria initiating the bodies immune response
what is dental plaque?
biofilm from bacteria found in the mouth, its soft so can be removed by a toothbrush, reduced by OH
what is the purpose of periodontal treatment?
reduce pathogens in the sub-gingival biofilm to a level which is conducive to healing
what is calculus?
plaque that has been calcified onto teeth
is calculus seen sub or supragingivally?
both
where is calculus commonly found?
lower incisors lingually due to submandibular/sublingual salivary gland
also seen upper 6 at parotid gland secretes here
why should calculus be removed?
If left it provides a rough surface which attracts further plaque bacteria
can calculus be removed by toothbrushing?
no, it’s tough so has to be removed professionally
what colour is supragingival calculus?
yellow/brown
where is supragingival calculus heaviest?
lingual lower incisors and buccal upper molars
how do u detect supragingival calculus?
Dry the tooth, it appears matt (careful - it looks similar to demineralised enamel)
what colour is subgingival calculus?
dark green/black
where is subgingival calculus heaviest?
same throughout the mouth
how do you detect subgingival calculus?
feel using BPE or cross calculus probe
radiograph (remember limitations)
what is a limitation of using a power scaler?
harder to detect residual deposits so check with it turned off
which one has a thinner tip, power or hand scaler?
power scaler
power scalers work by causing cavitation bubbles, what are these?
The scaler moves so fast it generates cavitation bubbles which then collapse creating a second shockwave which generates pressure and heat that knocks the calculus off and kills anaerobic bacteria
power scalers work by causing acoustic microstreaming, what is this?
movement of fluid adjacent to vibrating tip, generates stress within the immediate area damaging bacterial cell membrane, water flushes dead bacteria and their products out of the pocket
name the types of ultrasonic scalers
piezo-electricity or magnetostriction
an ultrasonic scaler tip oscillates at what frequency?
25042 kHz
why do you have to be cautious with piezo-electricity ultrasonic scalers?
Also used to remove dentine and caries
why do you have to be cautious with magnetostriction ultrasonic scaler
The stack oscillates/vibrates so if held too hard it can stop the tip oscillating/vibrating properly
Fast so generates heat so need water
how does a sonic scaler work?
generated from passage of compressed air
a sonic scaler tip oscillates at what frequency?
6-8kHz
describe the tip movement of a sonic scaler
elliptical -> circular
disadvantage of sonic scalers?
Causes more damage to root surface
what do you have to be cautious of when using ultrasonic/sonic scalers?
indwelling cardiac devices
respiratory infections AGP
decalcified enamel
ceramics and implants can be scratched
what are potential hazards of powered scalers?
thermal damage to tooth
incorrect angulation can damage tooth surface
but these surfaces in order of energy distribution from most to least powerful
what surfaces can you use directly on the tooth?
Use the concave surface and lateral sides, never the tip directly on the tooth
