What is the principal advantage of CAD/CAM fabrication compared with conventional laboratory technique?

Correct answer: D. Standardized, reproducible processing that removes several error-prone manual steps

• A. Occlusal evaluation and adjustment at delivery remain mandatory regardless of fabrication method.
• B. Esthetics is generally regarded as an area where skilled LABORATORY layering still holds an advantage. A milled monolithic block cannot easily reproduce the internal characterization and gradation a ceramist can build by hand — this is the recognized trade-off of chairside CAD/CAM.
• C. CAD/CAM demands MORE disciplined preparation, not less: rounded internal line angles, adequate and uniform reduction, a clearly defined margin, and no undercuts, since the scanner and milling bur have geometric limits.
• D. CORRECT. The core advantage of CAD/CAM is PROCESSING — the digital workflow removes multiple technique-sensitive manual stages including impression distortion, stone cast expansion, wax pattern distortion, investment expansion and casting shrinkage. Milling from an industrially manufactured, pre-sintered ceramic block also yields more homogeneous material with fewer internal voids than laboratory-processed ceramic. Added benefits are single-visit delivery and no need for a provisional restoration.

Note: CAD/CAM trade-offs: gains in reproducibility, speed, single-visit delivery and no provisional; limits in complex esthetic layering, milling bur resolution at fine internal detail, and the need for good scan access and moisture control.