Molar endo - ALL OF NATS Flashcards
what are the biological objectives of endodontic treatment?
Confine → prevent → remove → attempt → create
According to De Deus, how many distinct patterns do accessory canals occur in mandibular first molars?
3
In a single furcation canal, what percentage of accessory canals extend from the pulp chamber into the intraradicular region?
13% - which is why we seal the floor of the pulp chamber with RMGIC
What percentage of accessory canals extend from the coronal ⅓ of the major root canal to the furcation region? and which canal is it usually?
23%, distal root canal
What percentage have both lateral and furcation canals?
About 10%
What difficulty would you face during obturation treating a tooth with multiple accessory canals?
Just use thermoplastic wtv la raite cant use cold lateral compaction - cold lateral compaction not easy → use thermoplastic technique
What is the height from the pulpal floor to the furcation?
3mm
What is the height of the pulp chamber of a mandibular molar?
1.5mm
What is the height (gross) of the pulp chamber of a maxillary molar?
2mm
What is the height from buccal cusp to pulp chamber?
6mm
How many canals are in a maxillary first molar?
3-4 canals
Where is the 2nd MB canal located?
On a line between MB and palatal orifices
How many roots are in a mandibular 1st molar? How many canals in each?
2 - 2 in mesial, 1 or 2 in distal
What is the distolingual root of the mandibular 1st molar called?
Radix entomolaris
What is the mesiobuccal root of the mandibular 1st molar called?
Radix paramolaris <5%
How many roots are usually in a mandibular 2nd molar and how many canals?
2 roots, 3 canals
What is a common cause of endodontic failure? How often are they found?
Failure to identify all canals due to less than adequate access, missing canals found in 42% of endodontically failing teeth
What shape is the access cavity design on a maxillary molar?
Blunted triangular outline, base of triangle towards buccal, apex towards palatal, enture access within mesial half of tooth
What shape of the access cavity design on a mandibular molar?
Rhomboid shape to allow for exploration of second distal canal, access cavity within mesial half of tooth but extended as far distally as necessary
What are the objectives of creating an access?
Remove all caries,
conserve tooth tissue,
remove pulp chamber and horns while creating smooth axial walls,
remove all coronal pulp tissue,
local all root canal orifices,
avoid damage/perforation,
achieve straight line access,
minimise marginal leakage of restored tooth
What type of bur do you use to access a cavity?
Non-end cutting to avoid damage to pulpal floor
What happens when there is inadequate opening by poor access preparation?
Compromised cleaning + shaping, compromised instrumentation, coronal discolouration, prevents good obturation, instrument breakage, perforation, ledging
What may happen if there is mutilation of coronal tooth due to removal of too much tooth structure?
Coronal fracture
What may happen if there is inadequate caries removal?
Carious destruction of tooth and discolouration
What happens if there is labial/furcal perforation?
Can cause periodontal destruction and weakens tooth structure
What is the best way to establish a working length?
Electronic apex locator (EAL) and size 10 file
How do you check apical patency?
The ability to pass a small flexofile passively through the apical constriction without widening it
What do you irrigate the canal with?
Sodium hypochlorite
What do you use to establish a guide path?
ProGlider
At what speed and torque do you use the ProGlider at?
300rpm, 2Ncm
At what speed and torque do you use the shaping and finishing instruments at?
300rpm, 4Ncm
What should you record in the patient’s notes after taking the working length?
Record the WL and reference points
During final irrigation what do you use?
3ml sodium hypochlorite + ultrasonic activation in order to disrupt he biofilm,
3ml citric acid + ultrasonic activation, 3ml sodium hypochlorite
What should you use when doing lateral compaction to fit accessory canals?
Size B finger spreader
How do you obturate converging canals?
One GP should be placed to full WL, 2nd GP carefully inserted as far as possible, measure shorter one and cut off from apical end and place in canal
What is eliminated in the disinfection of the canal?
Pulp tissue, microbes, irritants, smear layer (dentinal mud), biofilm
What percentage of canal walls can be contacted by instruments in oval shaped canals?
40%
How does biofilm develop?
Deposition of a conditioning film, adhesion and colonisation of planktonic microorganisms in an extracellular amorphous matrix (EPS), co-adhesion of other organisms, detachment into surroundings
What is the chemical purpose of root canal irrigants?
To inactivate biofilm and endotoxins, dissolve tissue remnants/smear layer
What is the physical purpose of root canal irrigants?
To allow the flow of irrigant throughout RCS to detach biofilm and flush out debris
What are the properties of an ideal irrigant?
Broad antimicrobial spectrum against anaerobic and facultative microbes organised in biofilms, dissolve necrotic pulp tissue remnants, dissolve smear layer, be symmetrically non-toxic, non-caustic to periodontal tissues, little potential to cause anaphylactic reaction
What are the commonly used irrigants?
Sodium hypochlorite, EDTA, citric acid
What type of flow do irrigants have within the root canal?
Laminar, turbulent
What does laminar flow do?
Remove planktonic bacteria but only effective slightly beyond tip of needle
What is the frequency of ultrasonic?
25,000 cycles/second
- What is the area of stagnation known as?
Vapour lock effect
- How does turbulent flow work?
- Which is more likely to penetrate biofilm?
By sonic/ultrasonic agitation, acoustic streaming, cavitation
Turbulent flow
- What can be used to minimise coronal leakage?
RMGIC (vitrebond), smart dentine replacement (SDR)
- What are the properties of SDR?
A flowable bulk filler that can be placed up to 4mm, self levels and minimises shrinkage stress
- How do you provide coronal seal following obturation?
Clean access cavity with alcohol on microbrush, etch + bond in access, place SDR in pulp chamber and access cavity, leave 2mm to be filled with conventional composite if indirect restoration not prescribed
- According to the European society of Endodontology’s quality guidelines when should RCT follow-up be? What happens if they are not healed?
Clinical + r/g follow-up at least 1 year after treatment; further
review for 4 years
- What is defined as an endodontic emergency?
Pain or swelling caused by various stage of inflammation or infection of pulpal or periapical tissues
- What are the different types of endodontic pain?
Pre-treatment pain, interappointment pain, pain immediately following obturation, pain occurring sometime later associated with previously treated tooth
- What is recommended for analgesics of mild to moderate dental pain in adults according to the SDCEP?
Paracetamol, 2x500mg, 4x/day or ibuprofen, 2x200mg, 4x/day after food
- What is recommended for analgesics for moderate to severe dental pain in adults according to the SDCEP?
Increase the dose of ibuprofen to 3 tablets or ibuprofen + paracetamol together, diclofenac 50mg, 3x/day + paracetamol together
- What are the recommended first line antibiotic doses for dental infection in adults?
Amoxicillin 500mg 3x/day or phenoxymethylpenicillin 2x250mg 4x/day or metronidazole 400mg 3x/day
- What is dentine hypersensitivity?
An exaggerated response to application of stimulus to exposed dentine regardless of its location
- What is the presentation of dentine hypersensitivity?
Short, sharp pain from exposed dentine in response to stimuli which cannot be ascribed to any other dental defect or pathology