Endo Revision Questions

Question 1

Components of endo rotary insturments

Answer 1

taper - diameter change along working length
flute - groove to collect dentine and soft tissue
leading (cutting edge) - forms and deflects dentine chips
land - surface extending between flutes
releif - reduction in surface of land
helix angle - angle cutting axis forms with long axis of tooth

Question 2

Obturation material properties

Answer 2

easily manipualted with good working time
non irritant
sterile
radiopaque and does not disolour tooth
easily removed if required
unaffected by tissue fluids
dimesionally stable
seals canal laterally and apically 
inhibits bacterial growth

Question 3

Ideal properties of sealer

Answer 3

radiopaque 
non staining
slow set
easily mixed
bacteriostatic
insoluble in tissue fluids
no shrinkage on setting
establishes hermetic seal
tissue tolerant 
easy to remove in case of failure

Question 4

ZOE

Answer 4

antimicrobial and may affect cytoprotection
CaOH accelerates eugenolate hardening
free eugenol can act as irritant if remains
lose volume with time due to dissoloution - resin modifies this

Question 5

GI sealers

Answer 5

minimal antibacterial activity
avocated due to dentine bonding properties
difficult to remove if required

Question 6

Resin sealers

Answer 6

slow setting
good sealing and flow
intial toxicity that decline after 24hrs
paste paste mix
hydrophilic

Question 7

Calcium Silcate sealer

Answer 7

easy to use and quick set
no shrinkage on setting
bicompatible 
non resorable
good sealing abilites
high ph during initial 24hrs set
hydohpillic

Question 8

Medicated sealers

Answer 8

sealers containing parafor aldehyde NOT acceptable
lead and mercury components removed
casues permanenet toxic effects on periradicular tissues

Question 9

What is MTA used for

Answer 9

firect pulp caps
apexification
apecicotomy
pulpotomy
root resroption repair
furcation perforation repair
root canal filling material