Back to Access Cavities
MandibularTriangular
Mandibular Central Incisor
Mandibular Central Incisor - Axial View showing oval access cavity
Average Length20.7 mm
Root Development10 years
Universal #24, 25
FDI #31, 41
Access Cavity Design
ShapeTriangular/Oval
OrientationBuccolingual (NOT mesiodistal)
Entry PointLingual surface, just above cingulum
Canal Anatomy
Configurations
Single canal50-78%
Two canals (buccal + lingual)11-45% (varies by ethnicity)
Canal Positions
BBuccal Canal
Easier to locate, more accessible
LLingual Canal25-40%
Located beneath cingulum - MOST COMMONLY MISSED
Clinical Tips
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Warning
CRITICAL: Extend access gingivally into cingulum to find lingual canal
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Technique
Remove lingual shelf sufficiently - it shields the lingual canal orifice
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Technique
Use 20° distal angled radiograph to visualize two canals
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Tip
If file appears off-center on radiograph, suspect second canal