S2 - Root canal anatomy Flashcards
Mx central incisor (overall length, no. of canals)
23.6mm
1
Dr Rodrigo’s strategy for mx central RCT
WL 0.5-1mm from patency length
very end filled with sealer
vertical condensation not lateral condensation
Mx lateral incisor (overall L, canals, morphology and implication)
22.5mm
1 (3% have 2)
DP curvature (not straight root) -> must bend SS files* or may get ledge or perforation
*dont need to for NiTi
Mx canine
26(can be longer)
1 canal
DP curvature
Good tools for access cavity
burs: Endo-Z (best- to smooth walls and provide correct inclination), Tungsten carbide flat fissure bur, round burs
ultrasound tips: used to remove calcification in pulp floor and smooth walls, then use endo explorer to stab/find canals (DO NOT use burs in pulp floor)
*when ‘drop’ into pulp chamber felt, don’t keep drilling with burs, use Endo Z or other non-cutting tip bur and remove pulp roof
Access cavity for Mx centrals
- place bur perpendicular to palatal surface, drill 2-3mm
- change inclination along long axis of tooth until pulp chamber reached
need correct shape and be conservative
incisors = elongated triangle, canine = more oval
Mx 1st PM
21.5mm
mostly 2 root 2 canals - B and P (85%)
1 (8%)
3 (7%- like molar roots -2B, 1P)
Mx 2nd PM
21mm
1 (50%), 2 (50%)
1 root but 1-2 canals
(merge?)
Access cavity for PMs
start at middle between B and P cusps and make oval access cavity slowly, once you feel the drop, use a bur with non-cutting tip to smooth the walls (otherwise may drill into furcation)
Mx 1st molar
20mm
3 canals (30-40%) - 3 roots MB, DB, P
4 (60-80%) - MB2 (closer to P, most often MB2 and 1 merge but not always)
Issue with mx 1st molar
MB2 not always visible, must explore for it
Which is usually a bigger issue. Missing a MB2 that merges with MB1 or independent?
independent, some degree of disinfection of MB2 when merge at end (but bacteria still left in upper part) whereas if independent MB2 missed its a bigger issue
Mx 2nd molar
20mm
3 (75%), 2 (15%), 1 (10%), 4 (0.7% - difficult, narrow canal but need to look for it, use ultrasound tip and explorer)
Access cavity for mx molars
2B roots, 1P
-> triangle shaped access (base is B, apex P)
Md central and lateral
central 20.8mm
1 (73%), 2 (27% - B and L)
lateal 22mm
1(85%), 2 (15%)
(flattened canal - need to use Hedstroem file in circumferential filing motion at end to touch all the walls w canal flooded w NaOCl)
Common reason for failure in md incisors
small teeth, significant chances of having 2 canals
Access cavity for md incisors
same as mx, first perpendicular to lingual surface for 2-3mm, then go down long axis of tooth to reach pulp chamber
elongated triangle shape
Md canine
26mm
1 (88%), 2 (11%)
Access cavity for md canine
oval shape
following same technique, usually some roof remaining, need to remove this all of roof to have straight access
What must be achieved in ALL access cavities
remove/smooth all of pulp roof, to get straight access
Md 1st PM
22mm
1 (66%), 2 (31% - 1B, 1L)
Importance of taking 2 radiographs of different angulations
assess possibility of 2 canals
Md 2nd PM
22mm
1(90%), 2 (10%)
What is an uncommon anatomy for md premolar
C - shaped premolar
-> need to do CMP all the way around
Access cavity for md PM
oval shape between B and L cusps
Md 1st molar
21mm
3 (56%), 4 (36%), 2 (8%)
3- MB, ML, D canal usually centered in D root.
4- MB, ML, DB, DL. If u find 3 and they arent in a triangle, look for the DB/DL
2 rare variations you may find in Md 1st molar
- MM canal (mesial middle): fortunately it usually merges with MB or ML, problem if independent
- Radix entomolaris: extra L root - you will have MB, ML, D and something L
Summary of how many canals usually in teeth.
Mx central - 1
Mx lateral - 1
Mx canine - 1
1st PM - 2, 1, 3
2nd PM - 1 or 2, 50%/50%
1st molar -** 4**, 3
2nd molar - 3, 2, 1,4
Md central - 1, 2
Md lateral - 1, 2
Md canine -** 1,** 2
1st PM - ** 1,** 2
2nd PM - ** 1,** 2
1st molar -** 3,** 4, 2
2nd molar - **3, 2, 4
bold is most common, others are possible and listed from most common to
Md 2nd molar
21mm
3 (73%), 2 (16%), 4 (11%)
Rare variation of md 2nd molar
C shaped canals
Access cavity for md molar
triangle
