If you're buying dental zirconia or lithium disilicate for your lab, the biggest mistake is focusing only on the price per disc or ingot. The real cost includes failure rates, rework, and compatibility with your furnace and CAD/CAM system. I learned this the hard way: a 20% discount on zirconia discs cost me $1,200 in rework and a week of lost production.
I've been handling dental lab supply orders for 8 years. I've personally made (and documented) 7 significant mistakes, totaling roughly $12,000 in wasted budget. Now I maintain our team's checklist to prevent others from repeating my errors.
Why total cost of ownership matters more than unit price
Most labs focus on the per-unit price of zirconia discs and completely miss the sintering shrinkage variation, which can cause 5-10% of crowns to misfit. (Sintering shrinkage is the percentage the material shrinks during firing—typically 20-25% for zirconia, but it must be consistent.)
I assumed 'same specifications' meant identical results across vendors. Didn't verify. Turned out each had slightly different interpretations of 'translucency' and 'flexural strength.' The cheaper discs had a shrinkage rate that varied by ±0.5% from batch to batch, which was enough to throw off our milling units.
In my first year (2017), I made the classic mistake of ordering 50 zirconia discs from a new vendor because they were 20% cheaper. It looked fine on my screen. The result came back: 10% of the crowns didn't fit. 5 units, $1,200 in rework, straight to the trash. That's when I learned to always request a test batch and verify shrinkage data before committing to a large order.
What to check before you buy
Here's the checklist we now use for any new dental material supplier:
- Shrinkage consistency: Ask for batch-specific shrinkage data, not just a generic spec. According to ISO 6872:2015, dental ceramics are classified by flexural strength, but shrinkage isn't standardized—so you need vendor data.
- Flexural strength: For single-unit crowns, 800-1000 MPa is usually enough. For bridges, you need 1200 MPa or higher. Multilayer zirconia often has lower strength in the translucent layer, so check the weakest point.
- Compatibility: Confirm the material works with your furnace and CAM software. I once ordered a batch that required a different sintering profile—cost me $300 in wasted calibration time.
- Total cost of ownership (TCO): Calculate the cost per acceptable crown, not per disc. Include expected failure rate, rework labor, and shipping.
For lithium disilicate, the same logic applies. It's great for veneers and anterior crowns (high translucency), but not for bridges—its flexural strength is around 360-450 MPa, which is lower than zirconia. I have mixed feelings about cheap lithium disilicate ingots. On one hand, they save money upfront. On the other, we've seen 3-4% failure rates that cost more in the long run.
The boundary conditions: when this approach doesn't work
This checklist assumes you have time to test and validate a new supplier. If you're in a rush—say, a big case due next week—you might need to stick with a proven supplier even if they're more expensive. Honestly, I've done that. It feels like overpaying, but the risk of a failed batch is worse.
Also, for some applications, material choice matters more than supplier. For example, if you're making thin veneers, lithium disilicate is often superior to zirconia because of its translucency and wear characteristics. (Low wear glass ceramic is a key property for opposing dentition.) Don't force zirconia just because it's cheaper per unit—the total cost of a remake and patient dissatisfaction can be much higher.
Finally, this approach works best if you have a systematic way to track failures and costs. We use a simple spreadsheet: date, material, batch number, failure reason, cost. Over 18 months, we've caught 47 potential errors using this checklist—from shrinkage mismatches to expired materials.
Bottom line
Next time you order dental zirconia or lithium disilicate, ask for shrinkage data and a test batch. Calculate the cost per acceptable crown, not per disc. And remember: the cheapest material is rarely the cheapest overall. If you're a small lab doing mostly single-unit crowns, a mid-priced zirconia with consistent shrinkage will probably serve you better than a rock-bottom option. But if you're doing high-end esthetics, you might need to pay more for a premium multilayer zirconia—or switch to lithium disilicate for anterior cases.
I'm not 100% sure this will work for every lab, but it's saved us about $8,000 in rework over the past two years. Take this with a grain of salt: your mileage may vary depending on your furnace, CAM system, and case mix.
According to ISO 6872:2015, dental ceramics are classified by flexural strength into classes 1-6, with zirconia typically in class 5 (≥800 MPa) and lithium disilicate in class 3 or 4 (300-500 MPa). Always request the manufacturer's test data.