CSA endodontic instrumentation Flashcards
Why anaesthetic may not be profound during endo ?
o Hyperexcitability of nerve fibres – C nerve fibres
o Increased blood flow due to infection – removes anaesthetic faster
o Acidic pH of inflammatory products make anaesthetic less effective
o Patient factors like response to anaesthesia/differing pain threshold/anxiety levels
What If inadequate anaesthesia occurs
Intraligamentary/intrapulpal/intraosseous procedures occur
What are function of RubberD during endo
o Protection of airway o Protection from irritants o Prevention of contamination o Improves access & visualisation o Improves patient comfort
Endodontic RD involves ?
o Oroseal putty> forms seal around the tooth & RD
o Dental floss >secure clamp & prevent swallowing – eases dam through CP
o Wedgit>secures rubber dam
o Gauze & aspiration> improves patient comfort
What to check before accessing pulp chamber?
o All caries & defective restorations removed
o Crown deemed to be restorable
o sound coronal restoration can be placed
What does pre op radiograph show?
project tooth as near to its natural site as possible, show full roots & 2-3mm of periapical tissue,
What can we determine from radiograph?
o No./morphology of roots/canals
o Extent of current restoration
o Presence caries
o Presence of canal sclerosis/pulp stones/previous RCT/ Fractured instruments
What are the aims of coronal access?
- Remove roof of pulp chamber
- No damage to pulpal floor
- Straight line access
- Conservative
- Retentive to accommodate for temporary restoration
- knowledge of tooth & pulp anatomy essential
Whats needed to find canals?
require good light, magnification (loupes or microscope) & explorer
How to access pulp after coronal aspect prepped?
- Most of tooth removal carried out with high speed
- Slow speed burs = remove roof of pulp chamber if present & dentine from around canal openings
- Ultrasonic instru. may used to remove dentine around canal orifices
What burs are used when accessing pulp?
“safe ended” = no cutting flutes or diamonds at tip – used safely around floor of pulp chamber to remove dentine laterally w/o risk of perforation via floor
What does prep involve?
involves mechanical & cleaning & shaping w/ chemicals to disinfect canal
= Chemo mechanical
What does success of RCT depend on ?
cleaning/shaping – removes much debris as pos. whilst not compromising strength of the tooth
What is mechanical prep?
use of hand files
•Gates gladdens burs be used in straight coronal portion of canal
What is the straight coronal prep ?
occur 1st to create funnel shape
oBacteria/Necrotic tissue removed
o Files & Gates Glidden burs usedl
o Files then to prep coronal 2/3 of canal
What are gate gidden burs?
- 6 sizes – by number of grooves in the shank (0.5 – 1.5 mm)
- don’t cut at tip> won’t cut outside of canal
- stainless steel & designed to break easily at shank when stress applied
What is used to prep apical 1/3
- Stainless steel K Flex Files
* rubber stopper on each file used to indicate length of canal to reproducible landmark
What is chemical preparation ?
(EDTA) used with files to lubricate canal & remove smear layer
• Sodium Hypochlorite irrigation throughout
Why is SODIUM hypochlorite ideal?
- destroys microorg
- dissolves organic matter
- wets canals
- removes debris by flushing
- biocompatible
What are intra canal meds?
placed in canals between visits, when:
o persistent infection even w/ chemo mechanical cleaning
o Apex incomplete – stimulates apexification for immature teeth
o Insufficient time for obturation/preparation
What are requirements for intra canal med?
o Antibacterial o Aids periapical healing o Therapeutic o Anti-inflammatory o Long lasting o Non – irritant - Easy to use & remove o Cheap
What is most common intra canal med?
calcium hydroxide
What is aim of temporisation
o Seals tooth/ prevent contamination
o Restores function of tooth
o Prevents over eruption/drifting
o Restores aesthetics
What is used for interim temp. restoration ?
Kalzinol (zinc oxide eugenol),
glass ionomer, polycarboxylate cement, intermediate restorative material and
composite
What is obturation ?
- Once canals been cleaned/shaped
- provides 3D seal of canal system
- Gutta percha most commonly used
- Matched finger spreaders used to condense GP into canal & softened by heat/solvents
Why do we fill canal/obturate?
prevents microorganisms entering & reinfecting canal
- not possible to sterilise root canals completely – any residual micro. be trapped & w/o nutrients
What are used along Endo sealers ?
o Cement root filling material to canal
o Fill in voids
o Act as antibacterial
o Be radiopaque
What are common endo sealers
Zinc oxide eugenol, calcium hydroxide & glass ionomer
