Crown Prep QC: 3 CDTs Agreed on Only 62% of Scans

3 experienced CDTs. Same 226 scans. They agreed on 62%.

Three experienced dental technicians reviewed the same 226 crown prep scans. All of them were CDTs, not trained on the job. All of them followed the same SOPs.

They agreed on pass/fail in only 62% of cases.

This means that if you have more than one dental technician checking scans, there is no consistency in your lab.

Crown Prep QC is now open in our Early Access Program

The MovixTech Crown Prep QC AI employee “stands behind the doctor’s shoulder” and checks the prep. It checks margin line visibility, restorative space (occlusal and interproximal), and undercuts - identifies the issue, measures it, provides a report and a 3D image of the issue.

3D model of a crown prep scan, tooth 33, with the margin line highlighted where it is covered by gum, blood or saliva.

1. Consistency

Doctors leave a lab because of inconsistency.

Experienced technicians are not consistent. Every technician sees the same scan differently. In our study, three CDTs agreed on pass/fail in only 62% of cases.

3 CDTs reviewed the same 226 crown prep scans and agreed on pass/fail in 62% of cases. Example of one prep with three different verdicts.

Even top technicians cannot explain their rules. When we ask our customers what makes a scan good or bad, the top technicians usually cannot explain it. They say: “I cannot explain if it is good or bad. I just need to look at it.” So QC is a judgment call, and it depends on the person.

Outsourcing is cheap, but not consistent. You can outsource scan QC to the Philippines, China or other countries and get it done for cheap. But you still have to train the team, and the result depends on the people someone trained there. Cheap labor, no consistency.

The AI Employee measures every case against the lab’s SOPs. Same standard, every case, across the lab.

2. Chairside quality control

The doctor scans. In 2 minutes the AI Employee performs QC.

Faster turnaround time. At our customers, scan QC happens 36–47 hours after the doctor scans the patient. The AI Employee does it in 1–2 minutes. This cuts your turnaround time by 1–2 days.

Most labs want their customer support to talk to doctors, especially in the first 3 months. I think it is right. It is your sales point with the doctor. So at the start, the AI Employee emails the report to your customer support. Your customer support calls the doctor.

When you feel confident, the report can go to your doctors automatically, on behalf of your lab: by text message, by email, or through your portal, if you have one and doctors use it.

The doctor scans the prep, and within 2 minutes the AI Employee sends a report with a 3D image to the lab’s customer support, then directly to the doctor.

3. Retakes instead of remakes

Depending on the lab, about 10% of crown preps (up to 30% at DSOs) do not pass quality criteria.

If you ask the doctor for a retake an hour later, the patient has already left. There will be no retake. The doctor asks you to do something with what you have. You fix it digitally, and the crown doesn’t fit. You pay for the remake, and the doctor is unhappy.

The AI Employee checks the scan chairside, while the patient is still there. The doctor sees what exactly is wrong and fixes the prep right away. Not next week, when the patient has to come back. The chance of a retake is much higher. For the doctor this is real value from your lab.

4. Less labor cost

Labor is the most impactful line on your P&L.

We recorded the screens of dental technicians at our customer labs to see where their time goes. On one scan, a technician opens the scan, reads the Rx and the doctor’s comments, finds the product and the material, and applies the criteria for it: a zirconia crown needs a different occlusal space than e.max. Then the case goes back to the doctor, or the technician starts the design.

This takes 3–4 minutes per scan. Depending on the product, it is 10–20% of a technician’s time.

The fully loaded cost of scan QC by a US technician (salary, benefits, taxes, overhead) is $2.50 per scan. With us it costs $1.10–1.80, depending on your volume.

Example: a lab with 4,800 crown preps a month.

  • Time: 4,800 scans × 4 minutes = 19,200 minutes = 320 hours a month. That is 2 full-time technicians. Usually it is not two people: it is part of the work of several technicians.
  • Manual QC: 4,800 × $2.50 = $12,000 a month, $144,000 a year.
  • AI Employee: 4,800 × $1.10 = $5,280 a month, $63,360 a year.
  • Savings: $6,720 a month, $80,640 a year. That is 56% less.

5. Scalability

The AI Employee takes this boring work, and your technicians use the time for other tasks.

People come and go. The function stays. Technicians leave, new ones come, and every new one needs training. With the AI Employee, scan QC is fully automated. You train it once.

Grow without hiring. You can grow your lab or buy new labs without hiring and training more people for QC. Everything keeps working the same way.

Quality of EBITDA. If you plan to sell to PE, buyers look at your EBITDA. You can raise EBITDA with cheap labor in the Philippines, or with AI automation. But buyers look at the quality of EBITDA, not only at its size.

How it works

  1. The AI Employee automatically pulls the scan from your intraoral scanner portal.
  2. It reads the Rx and the doctor’s comments to identify the product and apply relevant QC criteria (zirconia crown or e.max).
  3. It performs quality control and sends the report.
The AI Employee logs into scanner portals, performs product-specific scan QC and routes each case: passed, fixable or not fixable.

An AI Employee that follows your rules

We train the AI Employee to follow your rules. It measures: 74% of the margin visible, 0.4 mm occlusal space, 0.3 mm undercut. Then, based on your thresholds, it decides pass or fail. One lab polishes a 0.5 mm undercut digitally. Another asks for a rescan. We set your thresholds together in the first 30 days.

A scan is not good or bad on its own. It is good or bad for the crown you are making. 0.4 mm of occlusal space is a problem for a PFM. A PFM needs 1.2 mm.

It reads the Rx and the doctor’s comments first. Very often the Rx and the doctor’s comments do not match: the Rx says one product, and the comments say another material. In 23% of Rx, the doctor gives the product information only in the comments. So the AI Employee first reads both and finds out what the doctor actually needs. Only then it performs QC.

Crown Prep QC report for tooth 33: margin visibility, restorative space and undercuts, each with measurements.

It is easy to start

Crown Prep QC does not require long integration. We don’t need to integrate with your LMS. We connect to your scanner portals in 2 minutes, and the Crown Prep AI Employee will be up and running. It will do quality control of all your crown preps.

We work with iTero, Medit, Shining 3D, DS Core, Dexis and AlliedStar. Your team enters the scanner credentials. We never see them.

My advice: start with one scanner. Set the thresholds with your team. Run it for a few weeks and check the results against what your technicians would have done. Then add the next scanner.

If you want, after that we can integrate with your lab management system, so you will see the QC results there too.

See what Crown Prep QC saves your lab

I’d be happy to calculate how much money your lab saves with Crown Prep QC AI Employee. Please pick a time in my Calendly.

You can also check what QC costs your lab today in our cost calculator.