What Amber Mill is
Amber Mill is a lithium disilicate glass-ceramic block for CAD/CAM milling, made by HASS Corporation in Gangneung, South Korea. The same family also includes Amber Mill Direct, a block that is already crystallized, and Amber Mill Q, a version with a zirconia core for implant crowns. This page covers the standard Amber Mill block, which is the version we use for veneers and single crowns.
The block is cleared by the US FDA (510(k) K160102) and carries the CE mark, and it is sold through HASS’s own company in the United States and through dental distributors in Europe and Australia. For a clinic abroad this matters in a practical way: the material in your patient’s mouth is a documented, traceable product rather than an unnamed generic block, and the batch is recorded on the case.
Like other lithium disilicate ceramics, Amber Mill is bonded rather than simply cemented, which is what lets very thin veneers and partial-coverage restorations work. It sits between feldspathic porcelain, which is more translucent but weaker, and zirconia, which is far stronger but needs more space for the same esthetic result.
Indications, translucency and shades
According to the HASS Instructions for Use, Amber Mill is indicated for single anterior and posterior crowns, veneers, inlays and onlays, and anterior three-unit bridges. HASS lists these as contraindications: posterior bridges that reach the molar region, bridges of four or more units, inlay-retained, cantilever and Maryland bridges, and patients with bruxism. For a bridge we use the most opaque level, MO, which the HASS manual names as the one suited to bridges.
The five translucency levels come from one block through the firing temperature:
| Level | Firing temperature | Typical use |
|---|
| HT+ | 840 °C | thin veneers, enamel-like incisal areas |
| HT | 850 °C | veneers, inlays and onlays |
| MT | 855 °C | between HT and LT |
| LT | 860 °C | crowns, dentin-like body |
| MO | 870 °C | discolored preparations, bridges |
Blocks come in 19 shades: A1 to A3.5, B1 to B4, C1 to C4, D2 to D4 and four bleach shades, W1 to W4. Final characterization is done with stains and glaze that fire below the crystallization temperature.
Strength and how it was measured
Two figures are published, and they mean different things. The Instructions for Use, which is the regulatory document, gives a flexural strength of over 300 MPa. HASS’s brochure gives a biaxial flexural strength of 450 MPa for the fully crystallized material and 250 MPa in the soft milling state; HASS labels this as its own internal data. We quote the regulatory figure on this page and treat the higher number as the manufacturer’s test result, not a design value.
Other values from the Instructions for Use: a coefficient of thermal expansion of 10.0 (±0.5) ×10⁻⁶ K⁻¹ and chemical solubility below 100 µg/cm². HASS also states a maximum temperature for any heat treatment, including re-firing; we keep all firings below 880 °C, which is inside the limit given in both the brochure and the manual.
Amber Mill has also been studied independently. A 48-month randomized split-mouth clinical trial compared it with another lithium disilicate CAD/CAM material in posterior Class II inlays (Journal of Dentistry, 2026), and laboratory studies have measured how the firing temperature controls its translucency (Materials, 2025).
Preparation and minimum thickness
HASS’s preparation guide gives these minimum thicknesses:
| Restoration | Minimum thickness |
|---|
| Thin veneer | 0.3 mm cervical and labial, 0.4 mm incisal |
| Veneer | 0.6 mm cervical and labial, 0.7 mm incisal |
| Anterior crown | 1.0 mm margin, 1.2 mm axial, 1.5 mm incisal |
| Posterior crown | 1.0 mm margin, 1.0–1.2 mm axial, 1.2–1.5 mm occlusal |
| Inlay and onlay | 1.0 mm |
For thin veneers the preparation should stay in enamel wherever possible so the bond can carry the restoration. If the scan shows less space than these values, our technicians flag it before milling and suggest either a small adjustment to the preparation or a different material.
Bonding and cementation
HASS recommends etching the fitting surface with 5% hydrofluoric acid for 20 seconds, rinsing and drying, applying a silane and then seating the restoration with a self-adhesive resin cement. The manual warns that etching longer than the stated time can weaken the ceramic. For veneers and inlays most clinicians use a full adhesive protocol with their own bonding system; please tell us your cement so we can match the internal surface and the cement space in the design.
Ordering Amber Mill from Khai Nguyen
In-lab working time for milled lithium disilicate is 1.5–5 working days, depending on the restoration and number of units. Overseas cases then ship by DHL Express, usually in 2–4 days. The lab works Monday to Saturday, 08:00–19:00 (Vietnam time), and is ISO 13485 certified. More on timing in Vietnam dental lab turnaround time and shipping.
With the case, please state:
- The restoration type and tooth numbers.
- The target translucency (HT+, HT, MT, LT or MO) or simply the effect you want, the VITA shade, the stump shade, and shade photos if available.
- Your cementation protocol.
See how we used Amber Mill in practice in our case study of ten Amber Mill veneers following the approved wax-up. Restorations are covered by our general warranty (6 months to 15 years depending on the material). To compare, see IPS e.max CAD and Celtra Duo. To discuss a case, please contact Khai Nguyen or follow our ordering process.
Technical values come from the HASS Amber Mill Instructions for Use, brochure and user’s manual. This page is written for dentists and dental technicians. Khai Nguyen Dental Lab fabricates restorations only on professional prescription and does not sell directly to patients.
