Back to Access Cavities
MaxillaryTriangular
Maxillary Second Molar
Maxillary Second Molar - Axial View showing triangular access with closely spaced canal orifices
Average Length20.0 mm
Root Development15 years
Universal #2, 15
FDI #17, 27
Access Cavity Design
ShapeTriangular
OrientationSmaller than first molar
Entry PointCentral pit
Canal Anatomy
Configurations
3 canals (MB, DB, P)60-70%
4 canals (with MB2)20-60%
Fused roots (2 roots)25-30%
Canal Positions
MBMesiobuccal
Similar to first molar but closer to other canals
DBDistobuccal
May be very close to MB in fused roots
PPalatal
Largest canal
MB2Mesiobuccal 220-60%
Lower prevalence than first molar
Clinical Tips
💡
Tip
Access smaller than first molar - canal orifices much closer together
💡
Tip
MB2 less prevalent (20-60%) than in first molar
⚠️
Warning
Watch for fused root variations - orifices may appear almost linear