Building a Same-Day Crown Workflow from Scratch
Same-day crown delivery — milling and sintering a zirconia crown in a single patient visit — has moved from a premium differentiator to an expectation in many markets. For a dental lab supporting an office that wants this capability, or for an office building its own in-house workflow, the requirements are specific and the workflow needs to be precise. Here's what the build-out looks like.
Equipment Required
Intraoral Scanner
The workflow starts with a digital impression. Any of the major IOS systems (Trios, Primescan, iTero, Medit) will work; the critical requirement is fast scan output that can be exported for CAD design. Scan-to-CAD file export time should be minutes, not hours.
CAD Software
exocad DentalCAD is the most common choice in US labs for open-system same-day workflows. Design time for a single-unit crown in exocad by a trained technician is typically 10–20 minutes. The faster and more accurate this step is, the tighter the overall timeline.
CAM Software and Milling Machine
You need a mill with fast milling cycle times for speed sintering-compatible zirconia. Typical pre-sintered zirconia milling time for a single crown: 15–20 minutes on a well-configured modern mill. The Aidite AMD-500S Pro and Roland DWX-52DCi both support fast milling strategies compatible with same-day workflows. CAM setup should use validated speed strategies for your material.
Speed Sintering Furnace
Standard sintering takes 6–8 hours. Same-day requires speed sintering: 60–90 minutes for materials validated for fast cycles. The Aidite sintering furnaces with speed-sintering programs, and Nabertherm units configured for fast cycles, are both appropriate choices. This is the most common bottleneck in same-day workflow setup — if the furnace isn't capable of validated speed sintering, the workflow fails.
Material Selection
Not all zirconia is validated for speed sintering. Use materials specifically approved for fast-cycle sintering by the manufacturer. Aidite AiZir SHT and compatible ultra-translucent zirconia formulations that have published speed sintering profiles are the appropriate choice. Using non-validated material on a speed cycle risks inadequate sintering and unpredictable mechanical properties.
The Workflow Timeline
- Tooth preparation and digital impression: 30–45 minutes (clinical)
- CAD design and approval: 15–25 minutes
- CAM setup and milling: 20–30 minutes
- Pre-sintering preparation: Color liquid application if needed (5–10 minutes + dry time)
- Speed sintering: 60–90 minutes
- Finishing, glazing, polish: 15–20 minutes
- Delivery: 3–4 hours total from scan to seat
Common Failure Points
- Scan quality: Poor scan = poor design = poor fit. Invest in scan quality and retake if the data is marginal.
- Speed sintering with non-validated material: Under-sintered restorations that look fine initially but fail early.
- Furnace calibration drift: A furnace running 20–30°C cold will produce under-sintered results on a speed cycle. Calibrate regularly.
- Tight timelines and rushing the CAD: Design errors that would be caught on a standard timeline get missed under time pressure. Build in CAD review checkpoints.
Where Lab Support Helps
Same-day doesn't require the lab to be in the office — if the office has a scanner and you have the milling and sintering setup, many offices transmit the digital impression to the lab for design, then receive the milled STL back for local sintering and finishing. Some labs handle design and milling while the office handles sintering. The workflow can be distributed; define handoff points clearly.