Why Traditional Impression Materials Fall Short
If you've ever had a dental crown made, you know the experience: your dentist packs a tray of gooey putty into your mouth and asks you to hold it there while it hardens. That putty is an impression material—alginate, polyether, or polyvinyl siloxane—and they all have problems. These materials shrink as they set and dry. Polyether shrinks by up to 0.8 percent, alginate shrinks even more (1 to 2.5 percent), and even the "better" polyvinyl siloxane shrinks by 0.1 to 0.3 percent. That might sound tiny, but when your crown is made from a shrunk impression, it won't fit as well.
This shrinkage keeps happening even after the impression is made. If your dentist doesn't rush your impression to the lab within 15 minutes, the material keeps changing shape. Then the lab makes a stone model from the impression, which adds even more potential for error. By the time your crown is made, the small errors have added up. That's why about 8 to 12 percent of crowns made from traditional impressions need to be remade in the patient's mouth because they don't fit properly.
Temperature and humidity also mess with traditional impression materials. If your dentist's office is warm and humid, the material absorbs water and changes shape differently than it would in a dry office. Your impression might look fine in the office but be a different size by the time it reaches the lab. This unpredictability is one big reason why many dentists are moving away from putty trays.
The Digital Scanning Revolution
With digital optical scanning, your dentist uses a small camera-like device to take a 3D picture of your tooth and the surrounding area. That picture is mathematically perfect—it doesn't shrink, doesn't absorb water, and doesn't change over time. The digital file stays exactly the same from the moment your dentist scans it until your crown comes back from the lab. The data transfer is so accurate that the error is less than 0.01 millimeter. It's basically perfect.
But digital scanning offers more than just accuracy. First, there's no gagging. No putty tray jamming into your mouth.
No awful taste or feeling of choking. About 40 to 45 percent of people hate the gagging sensation of traditional impressions, but with digital scanning, your dentist just guides a small wand over your teeth. You can actually see your tooth on the screen in real time as the dentist scans. Studies show that patient satisfaction jumps 30 to 40 percent when dentists switch to digital scanning.
Another huge advantage is speed. Your dentist can send your digital scan to the lab instantly over the internet. No waiting for overnight shipping.
No risk of the physical model getting damaged in transit. If you need your crown urgently, it can go to the lab within minutes. This cuts your total treatment time down by 2 to 3 days. Your dentist can also send your scan to multiple labs to compare prices and quality, all without making another model.
Your Crown Gets Made Faster and Better
When your dentist sends a digital scan to the lab, the lab doesn't have to create a stone model anymore. That saves them 2 to 4 hours per crown. Instead, the scan becomes a computer model instantly, and the lab technician starts designing your crown right away using specialized software. The computer can show exactly how your crown will look, check that it fits perfectly with your bite, and make sure the edges match your tooth perfectly. If something doesn't look right, the technician can fix it on the computer before any physical crown is made.
This is where quality control gets really good. Learning more about Digital Impression Intraoral Scanning can help you understand this better. The lab technician can measure every part of your crown digitally to make sure it's accurate before they ever mill the crown out of ceramic or metal.
They can virtually check your shade (color), contour (shape), and how your bite lines up. If there's a problem, they catch it immediately. This reduces the number of crowns that need to be remade because of design errors.
The lab also saves a ton of money and reduces waste. They don't have to keep stockpiles of stone, trays, and other materials. They can track exactly what materials they need and order only what they'll use. The milling machines get instructions optimized for the specific material being used, whether it's ceramic, metal, or something else. This efficiency means your crown gets better quality at a lower cost.
Scanning Is Gentle and Comfortable
Unlike traditional impressions, digital scanning doesn't require your dentist to shove a full tray deep into your mouth. The scanner only needs to capture your tooth preparation and the surrounding tissue—it can do this with just a small wand and some gentle gum retraction. Your dentist might use a retraction cord (a tiny string) to help them see the margin where the tooth preparation ends, but it's only in your mouth for a few seconds. No gagging.
Removing a traditional impression is actually painful for many people. The dentist has to pull the tray upward and outward, which stretches your gums and the tissues inside your cheeks. If your gums are already tender or inflamed, this removal can really hurt and even damage the tissue. With digital scanning, there's no removal trauma at all. You just open and close your mouth while the dentist takes pictures.
If you have a very limited ability to open your mouth, severe anxiety, or an extreme gag reflex, digital scanning can be even more helpful. Your dentist doesn't need to scan everything at once. You can do a few teeth at a time across multiple brief appointments, with each session lasting only a minute or two. This segmented approach makes it possible for even the most anxious patients to get a digital scan.
Your Crown Will Fit Better Than Ever Before
If your dentist scans your tooth twice, the two scans will be almost identical—they'll overlap 95 percent with less than 0.05 millimeters of difference. This repeatability is huge because it means your dentist can trust the first scan without making a backup. Traditional impressions are way less consistent because the tray position is different each time, the material is manipulated differently, and shrinkage varies. You can't compare two traditional impressions and get the same result.
Before your crown goes to the lab, your dentist can check the digital scan on the computer to make absolutely sure everything was captured correctly. The software can verify that the margins (edges of the tooth preparation) are clear, show where the tooth preparation ends, and confirm that your bite relationship is recorded. If something is missing or unclear, your dentist can scan just that specific area again instead of doing the whole tooth. This quality control process means your crown gets made right the first time.
The result is a crown that fits beautifully. Learning more about Digital Smile Design Planning Beautiful Smiles can help you understand this better. Crowns made from digital scans fit about 15 to 25 percent better than crowns from traditional impressions. A digital crown has a gap of only 65 to 85 micrometers between the crown and tooth, while a traditional crown typically has a gap of 110 to 150 micrometers. A smaller gap means less food and bacteria can sneak underneath, so your crown lasts longer and is less likely to get a cavity around the edge.
How Digital Scanning Saves Money (For Your Dentist and You)
Your dentist's investment in a digital scanning system is significant ($35,000 to $80,000), but it pays for itself quickly. Why? Because digital scanning is faster—about 5 to 10 minutes faster per crown compared to taking a traditional impression. That time savings lets your dentist see 2 to 3 additional patients per week. The dentist also saves money on impression materials and no longer pays the lab for model production—those savings alone add up to $20 to $35 per crown.
Here's the big money-saver: fewer remakes. When your dentist uses traditional impressions, about 8 to 12 percent of crowns need to be remade because they don't fit. With digital scanning, only 1 to 3 percent need remaking.
If a dentist makes 1,000 crowns per year with traditional impressions, that's 80 to 120 remakes. With digital scanning, it's only 10 to 30. That's tens of thousands of dollars saved per year.
Your dentist usually doesn't charge you extra for digital scanning. Instead, they absorb the cost savings as efficiency gains. What you get is a better crown that fits perfectly, made faster, without the gagging sensation. And because digital scanning leads to better outcomes and happier patients, your dentist builds a better reputation and gets more referrals. It's a win-win.
Digital Scanning Works in Any Climate
Traditional impression materials are fussy. Polyether shrinks if it gets humid. Polyvinyl siloxane shrinks if it gets warm. Alginate starts changing shape within 24 hours.
Even then, your dentist has to get it to the lab as soon as possible. But digital scans are tough—they work perfectly whether your dentist's office is cool or warm, dry or humid. A digital file is a digital file, and it never changes. It doesn't matter if your scan is processed immediately or if your dentist waits a week.
This reliability is especially important in areas with extreme weather or in offices with inadequate air conditioning. A traditional impression made on a hot, humid day will be different from one made on a cool, dry day. A digital scan is the same either way. Your dentist can also scan one tooth and send that scan to multiple labs to compare prices, or even reuse the same scan if they need adjustments months later.
Your dentist can also feel confident storing your digital files. A traditional impression might deteriorate or change shape while sitting in a file cabinet, but your digital scan stays perfect forever. This gives your dentist ultimate flexibility—they can process your crown immediately or delay without any loss of quality.
Your Dentist Is Learning This Technology Too
Not every dentist has digital scanning yet, but many are making the switch. When they do, there's a learning curve. Dentists need to practice with the scanner on about 30 to 50 patients before they get really good at it. For complex cases like scanning your entire mouth, it might take 100+ cases to master the technique.
During the transition, your dentist will probably keep traditional impression materials on hand as a backup in case the scanning equipment breaks down or if the situation calls for it. Many practices use a hybrid approach: they do a digital scan but also keep a conventional backup option available. As your dentist gets better at scanning, they'll use it more and more.
When your dentist first gets a scanner, appointments might take a few extra minutes. But as your dentist becomes skilled, scanning actually becomes faster than taking impressions. The whole process—from preparation to final scan—takes only a few minutes. Most patients appreciate how much more comfortable it is, even if the first appointment using the new scanner takes slightly longer.
Conclusion
Digital scanning is the future of dentistry. It eliminates the gagging, discomfort, and unpredictability of putty trays. Your crowns fit better, get made faster, and are less likely to need redoing. The technology keeps improving, and it's becoming the standard at most modern dental practices. If your dentist offers digital scanning, take them up on it—you'll have a much more pleasant experience and a better-fitting restoration.
> Key Takeaway: If you've ever had a dental crown made, you know the experience: your dentist packs a tray of gooey putty into your mouth and asks you to hold it there while it hardens.