Obturation 1

Question 1

Goals of obturation

Answer 1

• Completely fill prepared root canal space with biocompatible material
• Eliminate space within root canal where bacteria can colonize
• Eliminated bacterial leakage pathways
• Seal any irritants that were not removed inside the system

Question 2

When do we obturate?

Answer 2

1) Adequate preparation of the root canal is confirmed
2) Tooth is asymptomatic
3) Canals can be dried (no exudate)
4) Draining sinus is healed
5) Swelling has resolved
6) Anti-microbial dressing has been applied

Question 3

List requirements of root canal filling material

Answer 3

• Easily introduced to canal space
• Seal canal laterally, apically, and coronally
• No shrinkage
• Impervious to moisture
• Bacteriostatic
• Non-staining
• Biocompatible
• Sterile
• Removable

Question 4

List types of filling material:

Answer 4

• Single phase (not recommended)

- Dual phase -> solid core material + sealer cement

Question 5

What are Gutta-percha points?

Answer 5

• Solid core material

Question 6

Components of gutta-percha points

Answer 6

• Zinc oxide (75%)
• Gutta-percha (20%),
• other

Question 7

Sizes of gutta-percha points

Answer 7

• Standardized: 02, 04, 06 tapers

- Non-standardized: fine-fine < medium-fine < fine < fine-medium < medium < large < X-large

Question 8

Advantages of gutta-percha points

Answer 8

• Minimal tissue toxicity
• Easily adapts to canal
• Thermoplastic
• Easily removed
• Can be sterilized

Question 9

Disadvantages of gutta-percha points

Answer 9

• Non-rigid
• Non-adhesive (needs sealer)
• Displaced with pressure
• Shrinkage
• Slight elasticity

Question 10

Other filling material (not recommended)

Answer 10

• Silver points -> corrodes if contacts fluid, difficult to remove, do NOT seal canal laterally
• Paste root fillings -> high chance of paste extruding past apical foramen

Question 11

Sealers’ purpose

Answer 11

Fills voids and provides seal between core material, accessory points, and the dentinal wall

Question 12

Ideal properties of sealers:

Answer 12

• Same as root filling material
• Good adhesion to canal wall
• Easy mixing
• Slow setting
• Insoluble in tissue fluid

Question 13

List the types of sealers

Answer 13

• Zinc oxide-eugenol based
• Polymer resin
• Silicone based
• Glass ionomer

Question 14

What is procosol?

Answer 14

Zinc oxide-eugenol (ZOE) based cement (sealer).

Standard sealer

Question 15

Advantages of procosol

Answer 15

• Well tolerated by periapical tissues if extruded past apical foramen
• Provides good seal

Question 16

Disadvantages of procosol

Answer 16

• No adhesive properties

- Does NOT tolerate moisture

Question 17

What is AH26

Answer 17

Bisphenol epoxy resin sealer

Question 18

Advantages of AH26

Answer 18

• Slow setting
• Not affected by moisture
• Biocompatible
• Radiopaque
• Anti-microbial action

Question 19

Disadvantages

Answer 19

• Staining

- Releases formaldehyde (but AH PLUS doesn’t release formaldehyde)

Question 20

List condensation equipment

Answer 20

• Finger spreader
• K file
• 5/7 plugger
• Glick 1
• Westco-Mortensen plugger

Question 21

How is finger spreader used for condensation

Answer 21

• Used to laterally condense GP points in canal
• Accessory GP points are inserted in space made by Finger spreader
• Yellow = smaller; red = wider

Question 22

K-file in condensation

Answer 22

• Use to “paint” inside of canal with sealer

- Use size = MAF - 2

Question 23

5/7 Plugger in condensation

Answer 23

• Measure height of CEJ prior to obturation and set rubber stopper to height
• Used to check depth of vertical condensation. Want all Gutta-Percha to be below CEJ
• Used to vertically condense small canals

Question 24

Glick 1 in condensation

Answer 24

• Only instrument that is heated
• Used to heat GP
• Used to “sear off” intra-coronal GP

Question 25

Westco-mortenson plugger in condensation

Answer 25

Used to vertically condense large canals

Question 26

What is lateral condensation?

Answer 26

Multiple GP points are laterally packed and cemented with sealer

Question 27

Describe the steps of lateral condensation

Answer 27

1. Fit Master GP point into canal to final working length - similar size to MAF: use largest point that fits to FWL and has tugback. 2. Check that finger spread fits to at least 2 mm of FWL 3. Apply sealer to Master GP and canal walls 4. Use finger spread to create space adjacent to Master GP 5. Insert accessory GP point into open space (do NOT add sealer to accessory GP) 6. Repeat steps 4 and 5 until spreader only reaches to 2 mm apical of gingival margin 7. Perform heat out and vertical condensation

Question 28

What is heat out and vertical condensation?

Answer 28

Heat GP points and vertical condense with packer

Question 29

Describe steps in heat out and vertical condensation

Answer 29

1. Add more GP points if voids form | 2. Vertically condense until all GP is below CEJ: NO GP in pulp chamber due to discolouration

Question 30

What is single point technique

Answer 30

Just place on solid point into canal. Used with silver points. Unlikely to provide 3D seal. Technique sensitive

Question 31

Describe steps of vertical condensation

Answer 31

1. Measure GP about + 2mm short of tooth apex 2. Use HOT finger spread to apply heat to GP 3. Use Plunger to push GP down 4. Repeat 2 and 3 until apical region of root canal is filled 5. Back-fill the middle and coronal region of the canal

Question 32

How do you clean access cavity?

Answer 32

Microbrush dampened with: eucalyptus oil, chlorhexidine, alcohol

Question 33

List the ideal obturation criteria

Answer 33

- Obturation is stops within 1mm of root apex - No visible voids - Uniform density - Smooth lateral margins which reflect tapered shape of canal - No filling material above gingival margin