Digital Prosthodontics and CAD/CAM
Digital Prosthodontics and CAD/CAM tests intraoral scanning, design software, subtractive milling, additive printing, and digital occlusion. The exam expects workflow logic and verification, not claims that digital is automatically more accurate.
Core rules
- An intraoral scan must capture margins, finish lines, adjacent teeth, and opposing occlusion without blood or debris.
- Digital impressions can reduce distortion but still require moisture control and clear scanning paths.
- CAD design must respect path of insertion, connector size, minimal thickness, and cement space.
- Milling and printing have different resolution, material, and post-processing requirements.
- Virtual articulation helps, but clinical occlusal verification remains mandatory.
Worked example
A single molar crown is planned digitally. Reasoning: scan the preparation, adjacent teeth, and opposing arch; import into CAD; design the crown with adequate proximal contacts and 1.0-1.5 mm occlusal thickness; mill in the chosen material; verify fit and occlusion clinically. If the scan shows a blurred margin, rescan rather than design over an unreliable surface.
Traps that cost marks
- Scanning through saliva or blood.
- Accepting a digital scan without margin verification.
- Designing connectors that are too thin.
- Assuming printed and milled materials behave identically.
- Skipping clinical occlusal adjustment after CAD/CAM.