Obturation 1 Flashcards
Goals of obturation
- 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
When do we obturate?
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
List requirements of root canal filling material
- Easily introduced to canal space
- Seal canal laterally, apically, and coronally
- No shrinkage
- Impervious to moisture
- Bacteriostatic
- Non-staining
- Biocompatible
- Sterile
- Removable
List types of filling material:
- Single phase (not recommended)
- Dual phase -> solid core material + sealer cement
What are Gutta-percha points?
- Solid core material
Components of gutta-percha points
- Zinc oxide (75%)
- Gutta-percha (20%),
- other
Sizes of gutta-percha points
- Standardized: 02, 04, 06 tapers
- Non-standardized: fine-fine < medium-fine < fine < fine-medium < medium < large < X-large
Advantages of gutta-percha points
- Minimal tissue toxicity
- Easily adapts to canal
- Thermoplastic
- Easily removed
- Can be sterilized
Disadvantages of gutta-percha points
- Non-rigid
- Non-adhesive (needs sealer)
- Displaced with pressure
- Shrinkage
- Slight elasticity
Other filling material (not recommended)
- 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
Sealers’ purpose
Fills voids and provides seal between core material, accessory points, and the dentinal wall
Ideal properties of sealers:
- Same as root filling material
- Good adhesion to canal wall
- Easy mixing
- Slow setting
- Insoluble in tissue fluid
List the types of sealers
- Zinc oxide-eugenol based
- Polymer resin
- Silicone based
- Glass ionomer
What is procosol?
Zinc oxide-eugenol (ZOE) based cement (sealer).
Standard sealer
Advantages of procosol
- Well tolerated by periapical tissues if extruded past apical foramen
- Provides good seal
Disadvantages of procosol
- No adhesive properties
- Does NOT tolerate moisture
What is AH26
Bisphenol epoxy resin sealer
Advantages of AH26
- Slow setting
- Not affected by moisture
- Biocompatible
- Radiopaque
- Anti-microbial action
Disadvantages
- Staining
- Releases formaldehyde (but AH PLUS doesn’t release formaldehyde)
List condensation equipment
- Finger spreader
- K file
- 5/7 plugger
- Glick 1
- Westco-Mortensen plugger
How is finger spreader used for condensation
- Used to laterally condense GP points in canal
- Accessory GP points are inserted in space made by Finger spreader
- Yellow = smaller; red = wider
K-file in condensation
- Use to “paint” inside of canal with sealer
- Use size = MAF - 2
5/7 Plugger in condensation
- 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
Glick 1 in condensation
- Only instrument that is heated
- Used to heat GP
- Used to “sear off” intra-coronal GP
Westco-mortenson plugger in condensation
Used to vertically condense large canals
What is lateral condensation?
Multiple GP points are laterally packed and cemented with sealer
Describe the steps of lateral condensation
- Fit Master GP point into canal to final working length - similar size to MAF: use largest point that fits to FWL and has tugback.
- Check that finger spread fits to at least 2 mm of FWL
- Apply sealer to Master GP and canal walls
- Use finger spread to create space adjacent to Master GP
- Insert accessory GP point into open space (do NOT add sealer to accessory GP)
- Repeat steps 4 and 5 until spreader only reaches to 2 mm apical of gingival margin
- Perform heat out and vertical condensation
What is heat out and vertical condensation?
Heat GP points and vertical condense with packer
Describe steps in heat out and vertical condensation
- Add more GP points if voids form
2. Vertically condense until all GP is below CEJ: NO GP in pulp chamber due to discolouration
What is single point technique
Just place on solid point into canal. Used with silver points. Unlikely to provide 3D seal. Technique sensitive
Describe steps of vertical condensation
- Measure GP about + 2mm short of tooth apex
- Use HOT finger spread to apply heat to GP
- Use Plunger to push GP down
- Repeat 2 and 3 until apical region of root canal is filled
- Back-fill the middle and coronal region of the canal
How do you clean access cavity?
Microbrush dampened with: eucalyptus oil, chlorhexidine, alcohol
List the ideal obturation criteria
- 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
