Digital Impressions vs. Traditional Impressions: What's the Difference?

The Core Difference Between the Two Methods

At a basic level, one method captures a physical mold of the mouth, and the other captures a digital one. That difference sounds small until you look at what happens next, since everything downstream, from lab turnaround to remake rates, traces back to this first step.

How Traditional Dental Impressions Work

A traditional impression uses a tray loaded with material, typically alginate or a silicone-based compound, seated against the teeth and gums until it sets. Once removed, that physical mold is either poured into a stone model or scanned separately to digitize it for the lab.

Distortion can creep in at almost any point in that process: air bubbles trapped in the material, a tray that shifts before the material sets, moisture interfering with the impression surface, or slight shrinkage as the material cures before it's poured.

The lab then works from whichever version they receive, either the physical model itself or a digital scan of that model, which adds an extra conversion step compared to a case that started out digital.

How Digital Impressions Work

A digital impression is captured with a handheld intraoral scanner that's moved over the teeth and gumline, building a 3D model on screen in real time as it goes. There's no material to mix and no tray to seat.

Because the model builds live, the dentist can spot a gap or unclear area immediately and rescan just that spot before moving on. Once the scan is complete, the file is sent electronically to the lab or an in-house mill, with nothing to package or ship.

Digital vs. Traditional Impressions: Key Differences at a Glance

Before getting into the detail, here's how the two methods stack up across the factors that matter most to a practice.

The sections below unpack each of these factors, including where the research is more nuanced than a quick glance suggests.

Accuracy and Clinical Reliability

Accuracy of Digital Impressions

Digital scanners are built for trueness and precision, capturing tooth surfaces to a fine level of detail. A 2024 systematic review published in PMC found digital impressions generally achieve accuracy comparable to conventional methods, without a statistically significant difference in most clinical situations.

That said, accuracy still depends on operator technique. Scanning too quickly or skipping a section can leave gaps that need a second pass, so digital accuracy isn't automatic just because the equipment is capable of it.

Accuracy of Traditional Impressions

Traditional accuracy hinges on material handling: correct mixing ratios, adequate working time, and a tray that stays fully seated until the material sets. Get any of those wrong and the impression can distort before it's even removed.

Shrinkage, moisture contamination, and patient movement during setting are the most common culprits. Once the tray is removed, how quickly the model is poured and how it's stored afterward can introduce further, smaller inaccuracies.

How Accuracy Changes With Case Complexity

For single-unit restorative cases, both methods are generally reliable enough to produce a well-fitting result. The gap widens as a case gets more complex.

Longer-span cases and full-arch or multi-implant work put more strain on both techniques, and digital accuracy in particular can decline across a wide, unsupported span. Pairing a scan with photogrammetry has been shown to help close that gap for complex full-arch restorations, which is worth considering for practices that take on this case type regularly.

Patient Comfort and Experience

Digital Impressions and Patient Comfort

Without material sitting in the mouth, patients generally report less gagging and discomfort during a digital scan. A study published in BMC Oral Health found significantly higher comfort scores and better overall treatment acceptance among patients who received digital impressions.

That comfort difference matters most for treatment acceptance. A patient who has a smooth, low-stress impression experience is more likely to move forward with a proposed treatment plan without hesitating or asking to think it over.

Traditional Impressions and Patient Experience

Tray size, material taste and texture, and the several minutes of holding still while the material sets all shape how a patient experiences a traditional impression. Larger trays and full-arch impressions tend to be the most uncomfortable for patients with a sensitive gag reflex.

None of this means traditional impressions are unbearable for most patients, but for anyone with dental anxiety or a history of a difficult impression, that discomfort can influence whether they follow through on a recommended treatment plan.

Speed and Chair Time

How Digital Scanning Can Reduce Chair Time

With one of Incisive’s top scanners, scanning takes approximately 2–4 minutes for a single arch or 5–8 minutes for upper and lower arches plus bite capture. Total appointment time also includes preparation, review, and any additional passes needed. The clinician can review the model chairside and rescan missing or unclear areas before submitting the case.

Where Traditional Impressions Take More Time

Material preparation, tray placement, and the full setting time all add up before the impression is even removed. From there, the tray still needs inspection, and the physical model has to be produced and shipped or scanned before a lab can begin work.

It's worth separating chair time from overall case turnaround. A traditional impression might only take a few extra minutes in the chair, but the days spent on model production and shipping usually add more to the total timeline than the appointment itself.

Remakes, Errors, and Quality Control

Common Problems With Traditional Impressions

Voids from trapped air, tears in the material, pulled margins, general distortion, and models damaged in shipping are the most frequent sources of a failed traditional impression.

Common Problems With Digital Impressions

Digital scans aren't immune to errors either. Missing scan data in hard-to-reach areas, stitching or registration errors when a patient moves mid-scan, and difficulty capturing wet or bloody fields can all affect a case, and much of it still comes down to operator technique.

Newer scanners have gotten better at flagging these issues before a scan is sent out, but that's a safeguard, not a guarantee. A rushed scan can still leave a lab with a file that isn't quite usable.

How Each Workflow Handles Errors

A flawed traditional impression usually means redoing the entire thing, and sometimes that isn't discovered until the lab receives the model. A digital scan with a weak section can often be fixed with a quick rescan of just that area, though a poorly captured file can still make it to the lab if the gap wasn't caught chairside.

Cost and Practice Investment

Costs Associated With Traditional Impressions

Material alone typically runs $25 to $55 per case, depending on whether the practice uses standard alginate or a premium PVS, and that's before trays, model production, shipping to the lab, and the cost of redoing any impression that comes back flawed. None of these are large individually, but they recur with every case, and a practice running several impressions a day feels that add up over a year in a way a single per-case number doesn't quite capture.

Costs Associated With Digital Impressions

The scanner itself is the biggest upfront cost. Entry-level systems start around $15,000, and a fuller-featured setup typically runs $25,000 to $50,000 or more, depending on the brand, software bundle, and whether it's new or certified pre-owned. Staff training time adds to that initial investment.

Unlike traditional impressions, there's little to no material cost per case once the scanner is paid for. Some systems do carry ongoing maintenance fees or a subscription for software updates and cloud storage, and others don't charge one at all, so it's worth clarifying that specific point with a vendor before purchase since it changes the real cost of ownership over several years.

It's also worth asking prospective vendors how pricing scales if you add a second scanner or a second location later, since some contracts handle that more favorably than others.

When Does Digital Make Financial Sense?

There's no universal breakeven point. With traditional material alone running $25 to $55 per case, a practice doing several impressions a day can see that add up to a meaningful yearly figure well before factoring in remakes, shipping, or a slow lab turnaround. Against a scanner priced at $15,000 to $50,000, the payoff timeline depends heavily on case volume, how much crown, bridge, or implant work a practice handles, whether the receiving lab already supports digital files, and how often traditional impressions have historically needed to be redone.

Some networks, including no-cost equipment programs, help offset the upfront investment for practices that qualify, which changes that math considerably.

Which Impression Method Is Right for Your Practice?

When Digital Impressions May Be the Better Choice

Digital tends to make the most sense for practices with higher restorative or orthodontic volume, where patient comfort is a stated priority, and where the practice already works with a lab set up for digital files. It's also worth considering for practices that want faster, more direct communication with labs on frequent or time-sensitive cases.

When Traditional Impressions May Still Make Sense

Traditional impressions can still be the more practical choice for practices with lower impression volume, a limited technology budget, or an established lab relationship built entirely around physical models. Certain clinical situations, like specific undercuts or patients who don't tolerate the scanning process well, may also call for a traditional approach.

The right answer depends on your case mix, your volume, and how your existing lab relationship is set up, not on which method is newer. Practices that weigh those factors honestly tend to make a choice they don't second-guess a year later.

Frequently Asked Questions

Are digital impressions more accurate than traditional impressions?

Research shows the two methods are generally comparable in accuracy for most cases, without a statistically significant difference. Digital tends to be more consistent since it isn't affected by material shrinkage, though accuracy on both sides still depends on proper technique.

Are digital impressions more comfortable for patients?

Most patients report less discomfort with digital impressions, since there's no material or tray held in the mouth. Studies have found significantly higher comfort scores for digital scans, which can also support better treatment acceptance.

Are digital impressions faster than traditional impressions?

Digital scanning removes material mixing and setting time. With one of Incisive’s top scanners, capture takes approximately 2–4 minutes for a single arch or 5–8 minutes for upper and lower arches plus bite capture. The overall time difference depends on the case and the workflow being compared.

Can digital impressions be used for every dental case?

Digital impressions work well for the large majority of restorative, ortho, and denture cases. Complex full-arch or multi-implant cases sometimes benefit from pairing a scan with additional imaging to maintain accuracy across a longer span.

Are digital impressions worth the investment for a small practice?

It depends more on case volume and mix than practice size. A smaller practice with steady restorative or ortho work can often see a solid return through fewer remakes and lower per-case material costs, while very low-volume practices may see a slower payoff on the $15,000 to $50,000 equipment investment.