Root canal obturation Flashcards
(31 cards)
What are the 4 main aims of obturation?
- Entomb (completely surround with the filling material) any residual microorganosms within the root canal system.
- Completely seal all anatomical portals of entry/exit to root canal systems.
- Prevent reinfection of the root canal system by preventing ingress of oral microbes (i.e. coronal leakage from saliva contamination)
- Prevent entry of periradicular fluid, which may act as a source of nutrients for any microorganisms inhabiting the root canal system.
Give 12 requirements of an ideal root filling material.
look at notes
Where does gutta percha material originate from?
Mazer wood trees.
What are the 2 forms of gutta percha?
alpha form - used in injectable gutta percha forms
beta form - ised in gutta percha cones
What is the compositon of gutta percha used in root canal obturation?
zinc oxide
gp
metal sulphates
additives, pigments, tracde metal
What are the 3 types of gutta percha cones?
Standardised cones
Accessory cones used with spreaders
Greater taper cones used with protaper
What is gutta percha used in conjunction with in root canal obturation and what is produced?
- Root canal sealer
- Produces a homogeneous mass to seal the root canal space
What is the function of the sealer?
Fill the voids between:
- The root canal wall
- The GP root filling
- Between individual points during lateral condensation
Give 4 different sealers used in root canal obturation.
- Zinc oxide-eugenol based e.g. tubliseal, pulp canal sealer
- Calcium hydroxide based e.g. sealapex, apexit
- Resin-based e.g. AH plus
- Bioactive endodontic cements e.g. TotalFill BC sealer, BioRoot RCS.
Give 4 properties of zinc oxide-eugenol based sealer.
- Most widely used
- Successfully used over many years
- Demonstrates antimicrobial properites
- Decent seal
Give 4 properties of Calcium hydroxide based sealer.
- Releases calcium hydroxide to provide antimicrobial and osteogenic benefits.
- Risk of dissolution over time.
- Formation of voids can occur.
- Poor cohesive strength
Give 6 properties of resin-based sealer.
- Longer working time
- Adheres to dentine initially but contacts away on setting
- Flows well
- Easy to remove
- Initial cytotoxicity
- Once set biocompatible
Give 5 properties of bioactive endodontic cements sealer.
- Biocompatible
- Osteogenic potential
- Improve bond to dentine over other sealers
- Antimicrobial properties
- Difficult to remove in retreatment cases
Give the 8 steps of obturation.
- check mater apical cone clinically
- check master apical cone radiographically
- dry the canals
- apply the sealer
- cold lateral condensation
- mid fill radiograph
- cutback of gp
- post obtruation radiograph
What are the requirments of the master gutta percha point?
The master GP point is chosen that is:
- The same size as the Master Apical File (MAF)
- Measured to the same length as the working length (WL)
Before the master GP point is placed inside the root what must be done the the canal, canal walls and the master GP point?
The master GP point is chosen that is:
- The same size as the Master Apical File (MAF)
- Measured to the same length as the working length (WL)
After measuring the master GP point to the working length what 2 things are then carried out?
- The length is marked on the master GP point with tweezers.
- The master GP point is placed in a ‘wet’ canal.
- The point must fit well to the WL and have ‘tugback’
After inserting the master GP point has reached working length with tugback what must be taken and why?
- A master apical cone radiograph
- To confirm that the GP is binding within 1mm of the radiographic apex.
How is the correct spreader chosen for root canal obturation?
Use a spreader that:
- Goes to the WL
- Without binding but not too loose.
When is the spreader first inserted into the canal and how far should it go and how do you mark this length?
- After the master GP point has been tried in.
- Should go within 1mm from the working length.
- Mark with silicon stop
How do spreaders carry out lateral compaction and what is the result?
- Spreader applies lateral pressure to the master GP point.
- This creates spaced for the placement of accessory GP points.
- This process is repeated until the canal is three dimensionally obturated.
How is the spreader inserted into the canal and what is done after insertion?
- Inserted on the outer sied of the canal in order to not remove any points.
- 1mm shorter than WL.
- Keep the spreader and maintain firm apical pressure on it for a few seconds (15s) to laterally and apically compact the GP and gently remove with a twist.
How are accessory cones selected?
The cones are selected that match the spreader size.
Where are accessory cones placed exactly and what is applied on the cones?
The first accessory cone is inserted into the canal exactly where the spreader was. This process is repeated till the cnaal is filled to just below the canal orifice
Sealer
