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Same-Day Glass Ceramic: Batch Milling 20 Blocks in One Load

By Dr. Marcos B. Pesci · July 25, 2026 · 16 views

Same-day dentistry does not fail on design time. It fails on machine time — specifically, on how many times a technician has to walk over, unclamp, reload and restart.

The batch problem

A conventional block mill holds 1 block. Every crown is a load, a run and an unload. Do 8 units and you have interrupted the operator 8 times, and every one of those gaps is dead spindle time.

The DEPRAG W4 attacks this with a 20-position, four-sided super holder plus 6 pre-milled positions, using a zero-point change system. Load once, mill up to 20 blocks. Multiple crowns, inlays and veneers run without frequent stops — supporting a scan-to-seat workflow in roughly 4 hours.

Precision numbers that matter for lithium disilicate

Fine block work is unforgiving of machine slop. The W4's published figures:

2.5 kW, Ø62 mm water-cooled spindle at 60,000 rpm
C5-grade ball screws, P-grade guideways
Hybrid-ceramic bearings under 3 µm
5 µm repetition, 0.01 mm accuracy
Integrated casting body for thermal and vibration stability

The 12-tool magazine uses intelligent tool grouping with automatic tool change, so a mixed queue does not stall waiting for a bur swap.

Wet-only, 4-axis, and why that is the right scope

This is a purpose-built wet machine for glass-ceramic and pre-milled work, with a B-axis at 360 degrees. It is not trying to be a zirconia disc mill. That focus is what allows the 20-block holder and the same-day cycle in a 130 kg benchtop body.

Practical notes: an external compressor is required, the water tank is 10 L, and control is a 19.5-inch Windows 10 screen with fully wireless remote for device control and file transfer.

The financial case

Run the arithmetic on your own outsourcing. If you currently send out single-unit e.max style crowns, take your per-unit lab bill, multiply by monthly volume, and compare it against a machine that can produce a 20-block batch per load. For most practices and labs doing steady anterior and posterior single units, that is where the payback period lands — not in exotic capability.

Go deeper — full comparisons and specifications

These landing pages carry the complete side-by-side data, configuration options and current offers:

DEPRAG Dental Milling — W4, W5, W5 Pro, W5MAX and D5 Max explained.
Dental Milling Units Compared 2026 — every mill we carry, ranked by capability and price.
Milling Requirements — power, air, extraction and space before you order.