Obturation

Question 1

why obturate?

Answer 1

seal portals of entry apically, laterally, and coronally

Question 2

when do we obturate?

Answer 2

1. root canal system is adequately cleaned and shaped and s of such size and shape to accomodate the filling material and/or technique of choice
2. RCS is DRY
3. there is NO FOUL ODOR
4. tooth is NOT SYMPTOMATIC

Question 3

where do you fill/obturate to?

Answer 3

The cemento - dentinal junction

radio graphic apex

Question 4

what do you fill?

Answer 4

as much of the root canal system as possible

• the main root canal
• lateral/accessory canals
• fins and isthmuses

Question 5

what material are we using to fill?

Answer 5

gutta-percha and sealer

Question 6

what opacity should root filling material be?

Answer 6

radio-OPAQUE

Question 7

what are the components of gutta-percha?

Answer 7

20 % gutta percha
65% zinc oxide
10% metallic salts
5% waxes

Question 8

what are the two size of GP we are using?

Answer 8

1. fine medium

2. medium

Question 9

Gutta percha disadvantages

Answer 9

1. lack of rigidity
2. lack of length control
3. lacks adhesive quality
4. shrinkage

Question 10

what happens to gutts percha as it cools? what phase?

Answer 10

it shrinks

shrinkage occurs when go from alpha phase to beta phase

alpha phase is 42-44 celcius

beta phase is 37 degrees celcius

Question 11

describe sealers

Answer 11

they aid in establishing a good seal

they serve as a filler for canal irregularities and minor discrepancies between root canal wall and core filling material

they also seal lateral and the accessory canals and assist in microbial control

they can act as lubricants for the GP

Question 12

acceptable types of sealers?

Answer 12

1. ZOE based
   - zinc eugonel
   * *one we use
   - powder is zonc oxide and liquid is the eugenol
2. CaOH based
3. Resin based

Question 13

why cant you just use sealer?

Answer 13

it will dissolve in body fluids over time (months)

the GP and sealer together cause an intimate associated b/w the mixture and the canal walls to create the seal

Question 14

ideal properties of root canal sealers

Answer 14

1. tacky when mixed to provide good adhesion berween it and RCS when set
2. Hermetic (air tight seal)
3. RADIO-OPAQUE
4. very fine powder so can mix easily with liquid
5. doesn’t shrink when setting
6. want it to be

Question 15

liquid component of sealer

Answer 15

Eugonel

• 4-allyl- 2 methoxypheno
• balsam resin and water
• eugenol
• oil of clove

Question 16

how do we at BU obturate

Answer 16

Warm vertical compaction

- the multiple wave compaction SCHILDER TECHNIQUE

Question 17

Acceptable methods of obturation

Answer 17

1. Lateral compaction
2. carrier based compaction
3. hydraulic compaction
4. warm vertical compaction

Question 18

Acceptable methods of obturation

Answer 18

1. Lateral compaction
2. carrier based compaction
3. hydraulic compaction
4. warm vertical compaction

Question 19

describe lateral compaction

Answer 19

adding multiple GP cones and compacting them together

they are ‘cold-welded’ together but there are still gaps between many points which must be filled with sealer

Question 20

describe carrier based compaction

Answer 20

put in a heated carrier which appears to make it easier but actually technique sensitive and hard to retrieve and difficult to prepare a post space with

Question 21

describe hydraulic compaction / condensation with bioceramic sealer

Answer 21

sealer that is biocompatible

• non toxic
• doesnt cause irritation if extrusion occurs
• forming bond with dentin because forms hydroxyapatite during setting **
• hydrophilic

but it is expensive and very hard to retreat or creae a post space with

it is also not a 3D fill in large canals

Question 22

two techniques in warm vertical compaction?

Answer 22

1. multiple wave compaction
   - Schilder Technique
2. Continuous “SINGLE” wave compaction
   - buchannan Technique

Question 23

why do we compact?

Answer 23

to compensate for shrinkage of gutta percha

Question 24

how do we avoid loosing seal when doing warm vertical compaction?

Answer 24

since GP shrinks upon cooling from 42 degrees, any seal gained by heating threatens to be lost via shrinkage unless the ,material is COMPACTED to compensate for this shrinkage

Question 25

general description of warm vertical compaction

Answer 25

involves the application of heat and pressure to compact GP involve two steps : 1. down - pack 2. back fill

Question 26

9 pluggers range from what sizes?

Answer 26

``` 8 8 1/2 9 9 1/2 all the way to 12 ```

Question 27

tip diameters of pluggers that correspond to the associated plugger

Answer 27

``` 8 = .4 mm 8 1/2 =.5mm 9 = .6 mm 9 1/2 = .7 mm 10 = .8mm 10 1/2 = .9mm 11 = 1.1 mm 11 1/2= 1.3 mm 12 = 1.5 mm ```

Question 28

two things you need to apply before doing cone fit?

Answer 28

1. EDTA in canal - this solution must remain in canal for a minimum of 1-2minutes in order to remove the smear layer 2. place cone in NaOCL for 60 seconds to disinfect the cone before fitting

Question 29

how do you selec master cone?

Answer 29

select cone that is the same taper as the last instrument used at working length * need to feel A TUG BACK at the area of the apex if it does not go to working length it is too large

Question 30

how much of gutta percha do you coat with sealer?

Answer 30

the apical 3mm

Question 31

when heat hits GP how much farther from where it touches will it also heat?

Answer 31

about 3mm or so beyond

Question 32

first pluggers shuold be what size ?

Answer 32

big because you're at the coronal aspect

Question 33

what is a hotshot used for?

Answer 33

a GP gun for the back fill has 20, 23, or 25 gauge needles

Question 34

what did one study determine the maximum temperature bone could withstand before death of osseous cells?

Answer 34

occurred at 47 degrees celcius IF YOU CAUSE A TEN DEGREE OF CHANGE YOU COULD BURN IT -- cause damage to the PDL cells - But touch n heat usually only changes it about 2-3 degrees so studies have shown 3-4 seconds at 200 degrees farenheit are safe for most teeth

Question 35

what is the critical increase in the PDL before IRREVERSIBLE damage is sustained

Answer 35

10 degrees Farenhieit

Question 36

before sealing the access cavity (after obturation) what do you need to make sure?

Answer 36

it is asymptomatic, no discoloration, no pain, no clinical signs of failure like sinus tracts,