Loading 3D view…
M1 step 1 of 6 · Depth-cutting diamond
Depth-orient occlusal grooves
Cut depth grooves across the occlusal anatomy so you can see how deep the reduction will go before you join it up.
Your last prep
No prep scored yet. Your first score is free with an account.
Score a prep free- Target
- Occlusal reduction: 1.0–2.0 mm
- Why
- The grooves are your gauge for the occlusal reduction band.
- Watch
- Grooves deeper than the band leave nothing to correct later.
After the lesson: Retake the photos and score again on the 5 checkpoints.
Sources and 3D credits
Sources: Crown-prep criteria sheet, zirconia molar (#3), 2026–27 season, pp. 1–2 (checked 2026-10-28) · Cast-metal crown criteria sheet, 2025 season, criteria page (checked 2026-11-11)
3D model: molar30.glb: teeth #29–#31, jaw bone and gum. BodyParts3D, © 2008 Life Science Integrated Database Center (DBCLS); modified by Osler Press. CC BY-SA 2.1 JP · source
3D viewer code. three.js authors. MIT · source
3D viewer code. three.js authors. MIT · source
Step 1: Depth-orient occlusal grooves
No prep scored yet · target 1.0–2.0 mm
Loading 3D view…
TOOLDepth-cutting diamond
CHECKPOINTOcclusal reduction: 1.0–2.0 mm
WHYThe grooves are your gauge for the occlusal reduction band.
Do
Cut depth grooves across the occlusal anatomy so you can see how deep the reduction will go before you join it up.
WatchGrooves deeper than the band leave nothing to correct later.
Sources: Crown-prep criteria sheet, zirconia molar (#3), 2026–27 season, pp. 1–2 (checked 2026-10-28) · Cast-metal crown criteria sheet, 2025 season, criteria page (checked 2026-11-11)
3D model: molar30.glb: teeth #29–#31, jaw bone and gum. BodyParts3D, © 2008 Life Science Integrated Database Center (DBCLS); modified by Osler Press. CC BY-SA 2.1 JP · source
3D viewer code. three.js authors. MIT · source
3D viewer code. three.js authors. MIT · source
Outline · 8 parts
✓Criteria card✓Anatomy in 3D3Steps1Depth-orient occlusal grooves2Reduce occlusal table following anatomy3Add functional cusp bevel4Axially reduce walls5Open proximal surfaces with guarded bur6Finish continuous chamfer and verify clearance with putty index4Within vs outside5Check6Guided cut7Cut and score8Recall: day 3 and day 10Practice feedback against the 2026–27 published crown-prep criteria (molar). Not an exam or admissions result; your program and examiners decide.