Root Canal Anatomy and Access Flashcards
What kinds of root canals are there and how is each type cleaned
There are lots of types but main canals can be mechanically negotiated but lateral canals, fins and deltas can only be cleaned chemically
Where is the canal orifice
Often below the cusp tip or cingulum in posterior or anterior teeth respectively
What colour is the floor of the pulp chamber
Often different from rest and is more blue/grey than walls of the pulp chamber
What types of apical constrictions are there
Type A: Traditional, single constriction at the root apex
Type B: Tapering constriction that gets narrower and narrower towards the bottom
Type C: has multiple constrictions, looks like peristalsis motion
Type D: Parallel constriction, constricts before the root apex and has small canal to the apex
How many roots are there in maxillary incisors and what are their mean root canal lengths
- Mainly one root canal
- Max. central = 22.5mm
- Max. lateral = 22mm.
How should you try to access the cavity of the maxillary incisors
- Near incisal edge
- Leave cingulum intact if possible to provide max retention for a crown if needed
- Triangular shape access cavity
How many roots are there in mandibular incisors and what are their mean root canal lengths
- Over 40% have 2 canals that usually join in the apical third
- Canals found buccal and lingual
- Only 5% have 2 canals with 2 exits
- Mean length = 20.7mm
How should you try to access the cavity of the mandibular incisors
- Similar to maxillary incisors
- May have to be near incisor edge and slightly under the cingulum
How many roots are there in maxillary canines and what are their mean root canal lengths, where is the root wider
- Mainly one root canal
- Root wide labio-palatally
- Apical 1/3 maybe distal curvature
- Mean length = 26.5mm
How should you try to access the cavity of the maxillary canines
- Near incisor edge
- Leave cingulum intact if possible to provide max retention for a crown if needed
- Ovoid shape access cavity
How many roots are there in mandibular canines and what are their mean root canal lengths
- Mean length 22.5mm
- tooth resembles max canine but is smaller
- rarely has 2 roots
- 14% = 2 canals that join apically
- 6% = 2 canals separate exits
How should you try to access the cavity of the mandibular canines
- Near incisor edge
- Leave cingulum intact if possible to provide max retention for a crown if needed
- Ovoid shape access cavity
How many roots are there in Max. 1st premolars and what are their mean root canal lengths, where is the root wider
- Mean length = 20.6mm
- Generally 2 roots, 2 canals
- Lateral canals, apical region 49%
- Pulp chamber wide buccopalatal
How many roots are there in Max. 2nd premolars and what are their mean root canal lengths
- Mean length = 20.6mm
- Usually single rooted
- If 2 canals usually converge
How should you try to access the cavity of the Max premolars
- Outline ovoid bucco-palatal, for 1st premolar access usually extended more bucco-palatal
How many roots are there in Mand. premolars and what are their mean root canal lengths
- Mean length = 21.6mm
- Tend to be single root with a single canal
- Occasionally present with division of roots in the apical 1/2
How should you try to access the cavity of the Mand. premolars
- Outline ovoid bucco-palatal
What is the mean length of root canals in max. 1st molars
20.8mm
Describe the 4 pulp horns of Max. 1st molar
- Mesio-buccally longest and sharpest in outline
- Disto-buccally smaller than the Mesio-buccal horn but larger than the 2 Palatal pulp horns
How many canals are roots are there in the max. 1st molars
- Usually 3 roots, 4 canals
How should you try to access the cavity of the Max. 1st molar
- Mesial 2/3 of occlusal surface leaving oblique ridge leaving oblique ridge intact
- Triangular in outline, base buccally, apex palatal
What is an MB2 and how common is it
It is the second mesio-buccal canal in maxillary molars that is present in 71-93% of molars
Where is the MB2 usually found on max. 1st molars
- MB2 lies on an imaginary line joining the major canal and the palatal canal orifice, 1.82mm on average palatally
- A groove in this area on the floor of the pulp chamber maybe an indication of an MB2
AY BAWS CAN I HABE DE NOTE PLZ
You’re gonna need some mad magnification if you want to identify the MB2 well
Describe the anatomy of the root canals of the Max. 2nd molar
- Mean length = 20mm
- Smaller replica of 1st molar
- Roots less divergent
- Root fusion more frequent than 1st molars
- Buccal canal orifices tend to be closer together
- 3 roots, 3 canals
- Approx. 60% have 4 canals
How should you try to access the cavity of the Max. 2nd molar
- Mesial 2/3 of occlusal surface leaving oblique ridge intact
- Triangular in outline, base buccally, apex palatal
- 2nd molars show mesio-distal flattening of pulp chamber that is more mesially placed
Describe the anatomy of the root canals of the Mand. 1st molar
- Mean length = 21mm.
- Usually 2 roots, 3 canals
- 2 canals mesially, 1 distally
- 45% of canals in mesial root have 1 foramina
- 25% of distal roots have 2 canals, 1/2 of which have separate apical foramina
NB - if distal canal is central and in line with the Mesio-distal axis, most likely has one canal, if off centre look for another canal
How should you try to access the cavity of the Mand. 1st molar
- Trapezoid outline
- Placed in the mesial 2/3 of occlusal surface
Describe the anatomy of the root canals of the Mand. 2nd molar
- Mean length - 19.8mm
- Mesial root 2 canals and distal usually only 1
- Mesial canal can fuse apically to give one apical foramen
How should you try to access the cavity of the Mand. 2nd molar
- Trapezoid outline
- Placed in the mesial 2/3 of occlusal surface
- In 2nd molar can have a more triangular outline sometimes
What are some of the principles of cutting a coronal access cavity
- Remove entire contents of pulp chamber
- Allow inspection of all the pulp chamber
- To gain straight line access to the first curve of the root canal
What are the objectives of cutting a coronal access cavity
- Remove the entire roof of the pulp chamber
- Allow visualisation of all root canal orifices
- Be dynamic i.e. should be enlarged if the straight line access to all the canals cannot be obtained via initial cavity
- Have convergent wall in an apical direction to support the temporary dressing material
- To conserve as much toot tissue as possible to prevent weakening
