What are the 3 aims of obturation?
- prevents microorganism growth in the root canal space
- prevents regrowth of residual microbes which have survived debridement and disinfection
- prevents leakage into the root canal space
What are the 4 requirements for obturation?
- biomechanical preparation to a standard size
- asymptomatic
- dry canal with no exudate from PA tissue
- no sinus or swelling
What are the characteristics of an ideal root canal filling?
- inserted easily
- mouldable
- fills and seals the apex
- doesn’t expand or contract
- impermeable
- antiseptic
- easily removed
- chemically neutral
- durable
- doesn’t discolour the tooth
- radio-opaque so shows up on rads
Which 4 filling materials can be used for the core during obturation?
- gutta percha
- acrylic point
- resilon (resin based)
- silver point
What is Gutta Percha made out of?
- gutta percha (19-22%)
- zinc oxide (59-75%)
Which type of filling material is BioRoot RCS?
calcium silicate based root filling
(for permanent canal obturation)
What are the characteristics of BioRoot RCS?
- high pH (~11) so stops bacterial growth (prevents intracanal reinfection)
- biocompatible and resin free
- leakage resistance
What are the 7 obturation techniques?
- modified single cone
- cold lateral condensation
- warm lateral condensation
- vertical condensation
- thermo-plasticised gutta-percha
- carrier based systems
- thermo-mechanical compaction
Describe Modified Single Cone Obturation
- mix the sealer and apply into RC
- insert the master cone and ensure it goes to length
- cut the excess coronal part to the level of the root canal orifice with a heated instrument
- vertically condense the coronal third of the root canal with machtou pluggers
- place a RMGIC into canal orifice to seal it
What is the first step of Cold Lateral Condensation?
Master Apical Cone & Sealer
- identical size to MAF
- ‘tug back’ will be felt if there is a good fit at the working length
During Cold Lateral Condensation, if GP passes to the full length, how would this be adjusted?
adjust by cutting the tip 0.5mm to the working length or use a larger GP.
During Cold Lateral Condensation, what adjustments can be made if GP does not go to length?
use MAF to length, irrigate and dry before using a smaller size GP that fits to the working length.
What is the second step of Cold Lateral Condensation?
Finger Spreader
- come in size A, B, C and D
- bind 1-2mm from the working length
- used with firm pressure in an apical direction
- NO lateral pressure
Following the use of a master apical cone, sealer and a finger spreader, what are the remaining steps of Cold Lateral Condensation?
- accessory GP and sealer (use matching spreader for size A-D)
- spoon excavator used to remove excess 1mm below CEJ
- plugger used to condense warm GP and remove excess (don’t leave coronally due to stain risk)
- seal root canal with small amount of vitrebond (temp/definitive restoration), remove dam and take radiograph.
