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Prosthodontics

Crown Prep Checklist for OSCE

A short, structured guide to crown-prep steps examiners expect.

Quick Answers

What do examiners look for in crown prep?

Clear occlusal reduction, correct taper, smooth margins, and protection of adjacent tissues.

What is the ideal taper?

6–10° total convergence, with smooth continuous walls.

How much occlusal reduction?

Around 1.5–2.0 mm depending on crown type (PFM/zirconia/metal).

What margin should I choose?

Chamfer for metal/zirconia; shoulder or deep chamfer for PFM.

1. Why crown prep stations feel stressful

Crown preparations demand control, consistency, and awareness of anatomy—under time pressure. Examiners judge your process as much as the final prep.

A clean checklist keeps your actions organised and reduces mistakes like over-tapering or under-reduction.

2. Universal crown prep checklist

Use this for every OSCE station

1. Assess – occlusion, contacts, existing restorations, opposing arch.
2. Protect – rubber dam or soft tissue protection; guard adjacent teeth.
3. Occlusal reduction – depth grooves → uniform 1.5–2.0 mm reduction.
4. Functional cusp bevel – correct bevel on functional cusp for PFM/zirconia.
5. Axial reduction – smooth walls, 6–10° taper, maintain path of insertion.
6. Margin design – chamfer/shoulder depending on crown type.
7. Finishing – smooth surfaces, rounded line angles, no ledges.
8. Final checks – clearance, undercuts, margin continuity.

These eight steps cover every crown type: metal, PFM, lithium disilicate, and zirconia.

3. Margin choices explained

Margin selection is a high-yield OSCE point:

  • Chamfer: metal, zirconia.
  • Deep chamfer: lithium disilicate.
  • Shoulder: PFM with porcelain butt margin.

Examiners want to hear that your margin choice matches the crown material and aesthetic zone.

4. Occlusal reduction by crown type

Use these numbers in OSCE answers:

  • Metal: 1.0–1.5 mm
  • PFM: 1.5–2.0 mm
  • Zirconia: 1.0–1.5 mm
  • Lithium disilicate: 1.5–2.0 mm

5. Top mistakes candidates make

Avoid these common OSCE errors:

  • Over-tapered axial walls.
  • Flat occlusal table (loss of anatomy).
  • Violating pulp or over-reducing a cusp.
  • Unsupported enamel at the margins.
  • Not protecting adjacent teeth during reduction.

6. Fast practice workflow

10-minute crown practice drill

1. 2 minutes – review required clearance for the crown type.
2. 3 minutes – depth grooves + occlusal reduction.
3. 3 minutes – axial reduction + margin formation.
4. 2 minutes – finishing, smoothing, and checking path of insertion.

Repeat this drill daily with one tooth and one crown type until the sequence becomes automatic.

7. How DentAIstudy helps

DentAIstudy can build crown-prep OSCE checklists and short viva answers for prosthodontic stations in seconds.

  • Generates crown prep sequences based on material type.
  • Creates OSCE-style practice stems (e.g. “Prepare #36 for PFM”).
  • Provides reduction guidelines and stepwise instructions.
  • Helps you rehearse clean, structured OSCE answers daily.

Try Study Builder →

References

  • Rosenstiel SF, Land MF, Fujimoto J. Contemporary Fixed Prosthodontics. 5th ed. Elsevier.
  • Shillingburg HT, Hobo S, Whitsett LD. Fundamentals of Fixed Prosthodontics. 3rd ed. Quintessence.
  • Goodacre CJ, Campagni WV, Aquilino SA. Tooth preparations for complete crowns. J Prosthet Dent. 2001;85(4):363–376.
  • Güth JF, Zuch T, et al. Tooth preparation guidelines for modern all-ceramic crowns. Int J Esthet Dent. 2017;12(2):168–181.