Criteria card
M0 has no prep and no sheet of its own. This is the card every crown module scores against: the 2026–27 zirconia molar sheet, written for #3 (maxillary right first molar). Your practice tooth is usually #30 (mandibular right first molar) on a typodont. Your program's own rubric decides.
| Checkpoint | Acceptable | Marginally substandard | Critically deficient |
|---|---|---|---|
| Occlusal reduction | The occlusal reduction is ≥ 1.0 mm but ≤ 2.0 mm. | The occlusal reduction is > 2.0 mm but ≤ 2.5 mm. | The occlusal reduction is > 2.5 mm, or < 1.0 mm. |
| Axial taper | Taper is present, from nearly parallel to ≤ 12° per wall. | There is excessive taper that is > 12° and ≤ 16° per wall. | The taper is grossly over-reduced > 16° per wall. |
| Margin and line angles | The cervical margin is > 0.5 mm but ≤ 1.5 mm in width. | The cervical margin is > 1.5 mm but ≤ 2.0 mm in width. | The cervical margin is > 2.0 mm, or < 0.5 mm in width. |
| Adjacent tooth | The neighbors are untouched (#29 and #31 next to #30; #2 and #4 next to #3). | — | Damage to a neighbor that needs more than polishing. The sheets publish no millimetre band for it. |
| Putty clearance | The sectioned putty index shows a gap of at least the occlusal minimum over the prep. | — | The index touches the prep, or the gap is under the occlusal minimum. |
| Axial reduction | The axial tissue removal is ≥ 1.0 mm but ≤ 2.0 mm. | The axial tissue removal is > 2.0 mm but ≤ 2.5 mm. | The axial tissue removal is > 2.5 mm, or < 1.0 mm. |
Three confirmed marginally substandard over-preparation ratings on one procedure count as critically deficient, and two or more examiners rating any criterion critically deficient fail the procedure.
M0 has no prep and no sheet of its own. This is the card every crown module scores against: the 2026–27 zirconia molar sheet, written for #3 (maxillary right first molar). Your practice tooth is usually #30 (mandibular right first molar) on a typodont. Your program's own rubric decides.
| Checkpoint | Acceptable | Marginally substandard | Critically deficient |
|---|---|---|---|
| Occlusal reduction | The occlusal reduction is ≥ 1.0 mm but ≤ 2.0 mm. | The occlusal reduction is > 2.0 mm but ≤ 2.5 mm. | The occlusal reduction is > 2.5 mm, or < 1.0 mm. |
| Axial taper | Taper is present, from nearly parallel to ≤ 12° per wall. | There is excessive taper that is > 12° and ≤ 16° per wall. | The taper is grossly over-reduced > 16° per wall. |
| Margin and line angles | The cervical margin is > 0.5 mm but ≤ 1.5 mm in width. | The cervical margin is > 1.5 mm but ≤ 2.0 mm in width. | The cervical margin is > 2.0 mm, or < 0.5 mm in width. |
| Adjacent tooth | The neighbors are untouched (#29 and #31 next to #30; #2 and #4 next to #3). | — | Damage to a neighbor that needs more than polishing. The sheets publish no millimetre band for it. |
| Putty clearance | The sectioned putty index shows a gap of at least the occlusal minimum over the prep. | — | The index touches the prep, or the gap is under the occlusal minimum. |
| Axial reduction | The axial tissue removal is ≥ 1.0 mm but ≤ 2.0 mm. | The axial tissue removal is > 2.0 mm but ≤ 2.5 mm. | The axial tissue removal is > 2.5 mm, or < 1.0 mm. |
Three confirmed marginally substandard over-preparation ratings on one procedure count as critically deficient, and two or more examiners rating any criterion critically deficient fail the procedure.
Outline · 8 parts
1Criteria card2Anatomy in 3D3Steps1Find tooth #30 and tooth #32Name the five surfaces of #303Peel enamel, dentin and pulp4Read the five checkpoints on a finished prep5Photograph the prep on the grid card6Read your score band by band4Within 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.