Obturation and sealing the root canal system Flashcards
Single session
RC system is dry, asymptomatic tooth, and time permits, obturating at same visit
Multi-visit
If dry root canal system not achieved, infected or necrotic teeth, acutely symptomatic teeth, inadequate time: inter-appointment medication
Aims of obturation
Prevent coronal leakage of microorganisms or potential nutrients to support their growth into dead space of RC system
Prevent periapical or periodontal fluids percolating into RCs and feeding microorganisms
Entomb any residual microorganisms that have survived within RC system following mechanical and chemical prep
Completely seal all anatomical portals of entry/ exit to RC system
Prevent reinfection to RC system by denying access to oral bacteria
Inter-appointment dressing
Temp restoration (GIC, IRM)
Sponge underneath
Non-setting calcium hydroxide (left in root canal 1-4 weeks then flushed out with irrigation syringe and sodium hypochlorite)
Length of obturation
Totality of 3D filling of RC is more important than vertical extent alone
Kutler: termination should be to apical constriction, when apical constriction exists
Seltzer et al.: reaction to tissues were milder when instrumenting short of apex as compared to instrumenting beyond apex
Length of obturation: longitudinal studies
Strindberg: 775 endodontically trated root, reviewed up to 10 years after treatmentL highest success rate obturation terminated 1mm short of of radiographic apex
Swartz et all: overfilled canals 4x more likely to fail than those filled short of apex
Ideal properties of RC filling material
Radiopaque Inert Biocompatible Safe Long shelf life/ long working time Easily introduced into canal Easily removed Prevent leakage Adapt to irregular shape of root canals Dimensionally stable on setting Compatible with other materials Inexpensibe Bactericidal Insoluble in tissue fluids
GP master point
Same sizing as k files
Purpose of RC sealer
Take up voids around filler
Fill accessory and lateral canals
Fill space between GP points
Lubricate and help GP points to move
Ideal RC sealer
Biocompatible Non-toxic Safe Inexpensive Long shelf life/ adequate working time Easy to handle Radiopaque Dimensionally stable on setting Insoluble in tissue fluids
Type of RC sealer
ZOE based e.g. Tubliseal
Calcium hydroxide based e.g. Sealapex
Resin base e.g. AH Plus
Obturation techniques
Cold lateral condensation
Thermoplastic condensation
-warm lateral condensation
-warm vertical condensation
Paper points
Drying the canal before obturation
Cold lateral condensation
- Select master GP point
-standard master cones with coronal reference marked - Fit it in canal
- Mark GP at working length (then take confirmation x-ray) or grip it securely in endodontic locking tweezers
- Apply sealer to master point
- Paste canal walls with sealer
- Seat point into canal at full working length
- While spreader is in place, take accessory point in tweezers and dip it into sealer
- Do not leave points or GP in sealer, may soften, making insertion difficult
Accessory point immediately placed alongside master point, any delay will allow master point to relax and space will be lost - Repeat sequence using gradually larger spreaders and GP points until canal is filled
- Remove excess GP from canal orifice with heated intrument, and firmly compact remaining GP to seal coronal access of tooth
- Cut back all GP to entrance of RC orifice (level of CEJ), leaving clean pulp chamber
Hand spreaders and finger spreaders
Finger spreaders better tactile sensation
Finger less likely to induce fracture within RC system
For each size of spreader you have accessory points in same size
