Obturation

Question 1

what is the point in obturating

Answer 1

prevent passage of microorganisms and fluid along RC
block apical foramen + dentinal tubules + accessory canals
provide coronal seal
prevent reinfection

Question 2

ideal properties for obturating

Answer 2

biocompatible
dimensionally stable
able to seal
unaffected by oral fluids
insoluble
unsupportive of bacterial growth
radiopaque
can be removed

Question 3

GP constituents

Answer 3

isoprene polymer

20% GP
65% zinc oxide
10% radio pacifiers
5% plasticisers

Question 4

what is the function of a sealer

Answer 4

seal space between dentinal wall and core
fills voids and irregularities in canals + GP
aids lubrication

Question 5

properties of a sealer

Answer 5

tackiness for good adhesion
create hermetic seal
radiopacity
easily mixed
no shrinkage
non staining
bacteriostatic
insoluble in oral fluids

Question 6

name 4 sealers

Answer 6

ZOE
GI
resin
calcium silicate

Question 7

describe ZOE as a sealer

Answer 7

antimicrobial, cytoprotection
free eugenol can be irritant/toxic

Question 8

describe GI as a sealer

Answer 8

dentine bonding
minimal antimicrobial
high solubility
hard to remove

Question 9

describe resin as a sealer

Answer 9

good seal, slow set, initial toxicity declines 24hrs
AH plus
endorez

Question 10

describe calcium silicate as a sealer

Answer 10

pH 12.8
enhanced biocompatibility
no shrinkage, non-resorbable
ease of use
excellent seal
quick set

Question 11

what is the point of an intra-canal medicament
name 2

Answer 11

when RCT not completed in one visit
destroys microorganisms, prevents reinfection, reduces inflammation and control RR

ledermix
non set CaOH

Question 12

describe ledermix as an intra-canal medicament

Answer 12

corticosteroid and tetracycline
management of hot pulps
decreases pulpal inflammation
effective 5-7 days

Question 13

what is used to manage hot pulps

Answer 13

ledermix

Question 14

what is hot pulp

Answer 14

symptomatic irreversible pulpitis
extremely sensitive to heat
hard to anaesthetise as low pH inflamed tissue
C-fibres active and resistant

Question 15

describe non-setting CaOH as an intra-canal medicament

Answer 15

pH 12.5
antimicrobial prolonged activity
effective at removing debris
7 days
completely fill RC

Question 16

name and describe 4 techniques in obturation

Answer 16

cold lateral compaction -
common, low cost, controls, size matched cones
Master gutta percha cone inserted → spreader creates space → accessory cones added.

warm vertical compaction -Heat softens master cone → vertically compacted in segments with pluggers.
adv - excellent adaptation
disadv - technique sensitive

continuous wave obturation -Single cone heated and compacted apically in one continuous motion.

carrier-based obturation -Gutta percha coated on a plastic or metal carrier → heated and inserted.