Endo materials

Question 1

NiTi files are 8 times more flexible than stainless teel files

Answer 1

ye

Question 2

what are some irrigating sol’n?

Answer 2

• sodium hypochlorite
• EDTA
• H2O2
• chlorhexidine gluconate

Question 3

describe bleach as an irrigating sol’n

Answer 3

-NON-SPECIFIFC PROEOLITIC agent that removes ORGANIC MATERIALS;is antimicrobial and dissolves necrotic tissue

disinfx happens after 20 minutes

can heat up to 60-70 degrees to enhance effects; but do not overheat or will get bubbles–>go into pdl–>inflammation

Question 4

describe edta as an irrigating sol’n

Answer 4

-remove smear layer created by endodontic instrument

Question 5

describe chlorhexidine digluconate

Answer 5

kills biofilm bacteria but DOES NOT REMOVE THE BIOFILM LAYER

–> positively charged, binds to negatively charged phosphate molecules –> destabilizes membrane, cell lysics

Question 6

study starred table

Answer 6

ye

Question 7

describe CaOH as an intracanal medicine

Answer 7

-is antimicrobial and must directly contact bacteria
pH = 11
- poor solubility and diffusibility;
- not good for enterococci and yeasts as they can survive the alkaline pH

CaOH with camphoric p-monochlorophenol has a broader antibacterial spectrum

Question 8

describe the types of gutta percha

Answer 8

• alpha has a lower softening temp;
• has better properties than beta(flow wetting, adhesive)
• beta phase has higher softening temp

ZnO can be added for viscosity

and BaSO4 for radiopactiy

Question 9

major advantages of gutta percha?

Answer 9

• can be compressed to fill irregular roots
• non-irritant
• dimensionally stable and inert
• radiopaque
• can be softened when heated or used with solvents (xylol, chloroform, eucalyptus oil)
• can be removed from the canal if required

Question 10

what are the major disadvantages of gutta percha?

Answer 10

• distorted by pressure (can be pushed through apical foramen)
• not rigid
• sealer is necessary

Question 11

what are the voids filled with in root canals?

Answer 11

root canal cements

Question 12

what are the types of root canal sealants?

Answer 12

• ZOE
• GI
• CaOH
• Polymer

Question 13

what constituents can be added to sealants to improve bacteriocidal activity?

Answer 13

• bismuthcarbonates
• bismuth nitrates
• iodide
• sodium borates (acidic enviro–forms boric acid)

Question 14

what constituents can be added to sealants to improve radiopacity?

Answer 14

• barium
• bismuth
• silver powder

Question 15

describe zoe as a sealant material

Answer 15

0good seal
antibacterial poperties
- ‘0may cause tissue irritation

can also have unmod’d ZOE (no constituents added)

canalsohave reinforced zoe – add ethoxy benzoic acid

Question 16

describe glass ionomer as a sealant

Answer 16

fluoroalumino-silicate glass that reacts with poly carboxylic cid

• has low shrinkage and can bond to DENTIN
• can be modified to:
• increase working time
• improve transport to the canal
• adaptation tot he cnalal walls
• radiopaque
• retreatment

Question 17

hydrolytic silicate of calcium is used to protect the pulp–forms barrier and exerts a therapeutic effect on the pulp

Answer 17

ye

Question 18

what is MTA?

Answer 18

mineral trioxide aggregate

• • a cement
• tricalcium & dicalcium silicate, for tricalcium aluminate, gypsum, bismuthoxide
• handling is difficult and setting times long
• must be used wet

Question 19

why do we add canadian balsam to ZOE?

Answer 19

• to increase strength
• control flow properties
• add additional tackiness

Question 20

describe polymer as a sealing material

Answer 20

-addition-cured PVS impressional mateiral

SIDE

• smaller fill particles
• insoluble
• dimensionally stable
• excellent biocompatilbity
• NO bacteriocidal effect
• dooes not bond to canal walls

Question 21

cold application = lateral condensation

Answer 21

ye