For most of the history of dentistry, capturing the shape of your mouth meant a tray of putty held against your teeth while it set. It was unpleasant, it triggered the gag reflex in a lot of people, and if the material pulled or distorted on removal the whole thing was repeated.
A digital impression replaces that with a scan. A small wand passes over the teeth and gums, and a 3D model of your mouth appears on screen in a few minutes. Nothing sets, nothing is bitten into, and nothing is repeated because a tray moved.
What Is A Digital Dental Impression?
A digital dental impression is a three-dimensional digital model of the teeth and surrounding tissues, captured with an intraoral scanner instead of using physical materials.
The traditional method uses a tray loaded with impression material such as alginate or polyvinyl siloxane. The patient bites down on a tray, the material sets, and the resulting physical impression is poured in stone to make a model. A digital impression skips all of it. The scan is the model, and it exists as a digital file from the moment it is captured.
Historically, dental impressions were taken this way for every crown, denture and appliance. Digital dentistry has replaced most of that in restorative dentistry, and the intraoral scanner is now standard equipment in a modern dental office.
How Do Digital Impressions Work?
We use a Trios intraoral scanner, made by 3Shape.
The wand is about the size of an electric toothbrush head. It projects light onto the patient’s teeth and captures a rapid sequence of digital images, and software stitches them into a single continuous 3D model in real time. The scan builds on screen as it is taken, in colour, so any area missed is obvious immediately and can be rescanned in seconds rather than discovered days later at the dental lab.
A full upper and lower scan plus bite registration usually takes a few minutes. The digital data is then sent to a dental lab electronically, or straight to our in-house lab, where the final restoration is designed.
Modern optical scanning uses confocal microscopy or similar light projection technologies. What matters to you is that a digital scanner is a camera rather than a mould.
Digital Impressions Versus Traditional Impressions
The honest comparison between a digital impression and a conventional one, item by item:
- Comfort. No tray, no setting material, no bulk at the back of the mouth. Patient comfort is the difference most people notice, particularly anyone with a strong gag reflex.
- Time. Minutes rather than the wait for impression material to set, and no repeat if something goes wrong mid-scan.
- Accuracy. Conventional impressions can distort on removal, during transport, or when poured in stone. Each step introduces error. A digital scan removes those steps.
- Turnaround. A digital file reaches the dental laboratories instantly. A physical impression is couriered.
- Records. The scan is stored, so it can be compared against a scan of the patient’s mouth taken two years later to track recession or wear.
Traditional impression materials still have their place, which is covered below. But for most restorative and implant work, a digital impression is faster and more comfortable, and the accuracy is at least equivalent.
The Benefits Of Digital Impressions
Pulling the advantages of digital impressions together, for patients and dental professionals both:
For the patient: no trays and impression materials, no gag reflex, a shorter appointment, fewer repeat visits, and the ability to see a detailed 3D model of your own teeth on screen. For the dentist and the dental laboratory: accurate impressions with no pouring or shipping, a digital workflow that can be checked before the patient leaves the chair, and digital images that can be stored and revisited.
The practical effect is that digital dental impressions offer fewer points at which something can go wrong between the mouth and the finished dental restoration.
Are Digital Dental Impressions Accurate?
Yes, and for single units and short spans the published evidence puts accurate digital scans on a par with conventional impressions or better.
The reason is cumulative error. A traditional impression has to survive removal from the mouth, setting fully, transport to the dental laboratory and pouring in stone, and each stage can introduce a small distortion. Optical scanning captures the geometry once and it does not change afterwards.
Accuracy over longer spans is a more nuanced question, and it is the reason for the limitations section below.
Do Digital Impressions Hurt?
No. Nothing is injected and nothing sets against the teeth and gums. The wand touches each tooth lightly as it moves, and it can be paused at any point.
For patients with a strong gag reflex, this is the single biggest practical improvement in restorative dentistry in recent years. A conventional tray sits against the soft palate and has to stay there while the impression material sets. A scanner does not.
What Are Digital Impressions Used For?
The same things traditional dental impressions were taken for, and some things they could not do:
- Crown and bridge work, including a same-day crown milled from the scan
- Implant restorations, using scan bodies
- Clear aligners and orthodontics
- Night guards and occlusal splints
- Dentures and implant-supported prostheses
- Baseline records for monitoring gum recession or tooth wear over time
Digital Impressions For Dental Implants
Implant work adds a step. The scanner cannot see the implant itself, which sits beneath the gum, so a small component called a scan body is fitted into the implant first. Its shape is known to the software, which allows the implant position and angle to be calculated from the surface scan.
That digital model is then used to design the abutment and the final restoration, which our in-house lab produces. Because the scan goes straight into the design software, the restorative design and the implant position work from the same digital file rather than from a model of a model.
What Happens After Your Digital Impression?
The scan is checked on screen while you are still in the chair. Once it is complete, the digital file is either sent to a dental lab or opened directly in our own design software.
From there the crown, bridge or appliance is designed against the 3D model and manufactured, either milled or 3D printed. For some cases the restoration can be produced the same day. For others it returns from the dental laboratories at a second appointment, which is when it is fitted and adjusted.
Because the digital data is stored, a replacement years later can often be designed without scanning again.
What Are The Limitations Of Digital Impressions?
Every dental practice page on this subject lists the benefits. Fewer explain where the technology struggles, and the limits matter more than the advantages when they apply to your case.
Deep subgingival margins. An intraoral scanner is a camera. If a preparation margin sits well below the gum and the tissue cannot be retracted enough to expose it, the scanner cannot capture what it cannot see. Conventional impression material can flow into a space the camera cannot reach.
Bleeding and moisture. Blood or saliva over a margin degrades the scan. Good tissue management matters more with digital systems than with conventional impressions.
Fully edentulous jaws. Mobile soft tissue with no fixed landmarks is genuinely difficult to scan accurately, and this is an area where conventional technique still holds ground.
Long-span full-arch implant cases. This is the important one. Over a full arch, small errors accumulate across the scan, and the accuracy required to make a one-piece framework fit passively is beyond what an intraoral digital scan alone reliably delivers. For those cases we use photogrammetry, which measures the spatial relationship between implants directly rather than by stitching a surface scan together. The intraoral scan still captures the soft tissue and the opposing teeth. The two techniques do different jobs, and full-arch work needs both.
Any practice telling you a scanner solves everything is overselling it.
How Much Do Digital Dental Impressions Cost?
For a patient, a digital impression is not usually a separate line item. It is part of the cost of the crown, the implant restoration or the appliance being made, in the same way a conventional impression was. Using a digital impression system rather than trays and impression materials does not add a fee here.
If you have searched this and found figures in the tens of thousands, those are the purchase prices of the scanners themselves, which is a dental practice equipment question rather than a patient one.
Common Questions
How long does a digital scan take? A few minutes for upper and lower teeth plus the bite. Longer for complex full-arch cases.
Is there radiation? No. Using an intraoral scanner involves visible light only. It is not an x-ray, and it is a different device from the CBCT scanner used for implant planning.
Can I see the scan? Yes, and we would rather you did. The 3D model is on screen in the room, and it is far easier to explain a treatment plan against a model of your mouth than against a description.
What if I have a strong gag reflex? Tell us before we start. The scan can be captured in short sections with breaks, which is not possible with a tray of setting material.
Are digital impressions better than traditional ones? For most restorative and implant dentistry, yes, on comfort, speed and workflow, with accuracy at least equivalent. For the specific situations listed above, not always. That is a clinical judgement rather than a blanket answer.
Do you still take conventional impressions? Occasionally, where the case calls for it. The scanner is a tool, not a policy.
Can a digital impression be used as an alternative to a mould for dentures? Sometimes. It depends how much of the jaw is edentulous and how mobile the tissue is.
Speak To A Periodontist
If you are considering implants or restorative treatment and the memory of a putty tray is putting you off, it is worth knowing that most of that has gone.
Our periodontists have treated patients across Manhattan, Nutley, Long Island and Westchester for over twenty years. Call (347) 493-2439 or book a consultation. A 3D CBCT scan is included at your consultation at no charge.
