Digital Scanning (Intraoral Scans)

Intraoral scanners are used for diagnosis and for making restorations or custom devices¹ in restorative dentistry, implant work and orthodontics. A 2017 review of 132 studies describes these uses, among others:

• Crowns, bridges, inlays and onlays. The scan records the prepared tooth, its neighbours and the opposing teeth. Our dental crowns page explains what a crown involves.
• Crowns and bridges on implants. A small cylinder called a scan body is screwed onto each implant, so that the scan can record the 3D position of the implant¹. See our dental implant treatment page.
• Planning implant surgery. A scan of the teeth and gums can be combined with a CBCT scan¹ of the bone. Together they are used to plan where implants go and to design a surgical guide.
• Orthodontics. Scans are used for diagnosis and planning, and as the starting point for aligners and other custom-made appliances¹.
• Records and explanation. A 3D model can be kept as a record of your mouth, and it can help the dentist show you what they see.
• Smile design, posts and cores (built into a root-filled tooth to hold a crown) and partial dentures, according to the same review. It found only a few studies on scans for partial or complete dentures¹.

For complete dentures, scanning a mouth with no teeth is harder; see "When conventional impressions may be used" below.

Scanners and techniques differ, so the details vary. The outline below is typical for a crown or bridge, and the model builds up on a screen as the scan goes on.

Older scanners needed a thin powder on the teeth. More recent ones can scan without powder¹. You keep your mouth open while the tip of the scanner is moved over your teeth, including the back teeth. The size of the tip varies between scanners, and a smaller tip is preferable for comfort¹. If part of the scan is unclear, that part can be deleted and captured again without repeating the entire procedure¹.

A scan can only record what the scanner can see. The dentist checks the model before it is used. A 2017 review notes that the dentist and the dental technician can assess the quality of the scan in real time¹. If the file reaches the laboratory while you are still there, the technician can ask straight away for another scan¹. A problem found later may mean another visit.

What affects the quality of a scan

• Edges under the gum. Where the edge of a prepared tooth lies under the gum, it can be hard to capture. Unlike impression material, light cannot physically push the gum aside¹. A thin cord placed between the tooth and the gum helps to show the edge.
• Bleeding. Blood may hide the edges¹ of the preparation.
• Gum health. As with conventional impressions, healthy soft tissues are essential for a good scan¹.
• Experience and technique. There is a learning curve¹ for the person scanning. It is also still unclear whether one scanning strategy is better than another¹.
• The scanner. Studies, almost all in the laboratory, found that different scanners have different accuracy¹.

Colour and shade

Some scanners record colour. The 2017 review sees colour information as useful mainly for communication with the patient¹, and of less clinical importance. For the shade of a crown or veneer, a 2025 meta-analysis compared scanners with a measuring instrument (a spectrophotometer). A shade tab is one sample tooth in a shade guide. The scanners picked the same tab as the instrument in about 38 in 100 readings with one guide, and about 28 in 100 with another². Its authors do not recommend choosing shade with an intraoral scanner, although the certainty of this evidence was very low.

The shade is usually chosen with a shade guide, and the light in the room matters. In one laboratory study, dentists with normal colour vision matched shades better under a standard daylight lamp than under a tungsten bulb³. In another, handheld shade-matching lights and training both improved dental students' scores⁴. Our dental laboratory page explains how the shade reaches the laboratory.

A scan becomes a digital file. With a conventional impression, a plaster model is usually poured before anything is made. With a scan, no plaster model is needed¹, and the 3D model can be sent to the dental laboratory electronically¹.

Working from the scan, the restoration is usually designed on a computer (CAD) and then made by machine, for example milled from a block (CAM). Some clinics design and mill restorations in the clinic itself¹ from the scan; others send the file to a laboratory. Your dentist will tell you which applies to your treatment, and you can ask for it in writing. Our CAD/CAM page covers design, manufacture and what the evidence says about restorations made this way.

For implants, the scan of the teeth and gums can be superimposed on a CBCT scan¹ of the bone. Together they show the teeth, the gum surface and the bone. They are used to plan the position of each implant and to design a surgical guide. Our digital treatment planning page covers planning software, guides and their limits.

The scan is a record, not a plan. A dentist still decides what the restoration or treatment should be, and the laboratory and the planning software work from that decision.

The findings below come from published studies, not from our own records.

• No impression tray. A scan avoids the tray of setting material. Some people, for example those with a strong gag reflex¹, find a tray hard to tolerate.
• Usually quicker. A 2021 systematic review of 17 clinical studies in 437 patients found scanning overall faster than conventional impressions⁵ for crowns, bridges and implant work. The results were described study by study and not pooled. In one trial, a conventional technique was faster. Scans also needed more retakes, though the average retake time was lower⁵.
• Generally preferred by patients. In the same review, scanning was generally preferred⁵. The one trial in which the conventional technique was faster found no difference in comfort.
• Similar results for the restorations. The studies in that review that followed the restorations reported similar results with both methods⁵.
• Time saved after the scan. A 2017 review notes that most of the time saved comes afterwards, during the steps that follow¹, not from the scan itself.
• Seeing your own mouth. With a model on the screen, patients can feel more involved in their treatment¹, and the dentist can show you what they see.

What it is like

You need to keep your mouth open while the tip is moved around, and reaching the back teeth can be awkward. Tell the dentist if you need a break.

Accuracy here means how closely the scan matches your mouth. It is measured mostly in laboratory studies, and it is not the same as how long a restoration lasts. The studies below compare methods in general. They do not show how accurate any particular scanner, or any particular clinic's scans, are.

• Single crowns and short bridges. The 2017 review judged scan accuracy clinically satisfactory and similar to that of conventional impressions¹ for single teeth. It reached the same view for bridges of up to four or five units (each unit is one tooth of the bridge).
• Long bridges and full arches. The same review found that scans did not appear to have the same accuracy¹ for long bridges and full-arch work, on teeth or implants. It also warned that newer scanners improve faster than studies can be published.
• Full-arch bridges on implants. A 2025 meta-analysis covered 37 studies, 30 of them laboratory studies. It found no significant overall difference in accuracy⁶ between digital and conventional impressions. Intraoral scanners on their own did not differ from conventional impressions⁶. With more than four implants, conventional impressions were slightly more accurate⁶ than digital methods taken together (intraoral scans and photogrammetry, a camera-based method). The authors suggest that accuracy may decline when scanning arches with more than four implants⁶. Finding no significant difference does not prove that the two methods are equal.
• Implants where some natural teeth remain. A 2025 review of seven clinical studies in 151 patients found digital impressions a clinically acceptable alternative for short-span implant restorations⁷. Digital impressions differed less from the reference implant positions on one measure, with no difference in angle, but the studies varied widely. The authors advise caution with long spans or angled implants⁷.
• Edges under the gum and bleeding. Both can stop the scanner recording the edge of a prepared tooth (see "Scan review and data quality" above).
• Shade. A 2025 review advised against choosing the shade with a scanner (see above).

A conventional impression is still a normal choice, and neither method suits every case. Reasons it may be used include:

• Long bridges and full-arch work, especially on many implants (see "Accuracy limitations").
• Edges deep under the gum. Light cannot push the gum aside, and some authors suggest combining the two methods¹, partly using impression material. With either method, healthy gums are essential¹ and bleeding has to be controlled.
• Complete dentures. For a mouth with no teeth, scanning still presents some issues¹. There are few fixed reference points, and the scan cannot record how the soft tissues move. See our dentures page.
• Angled implants or long spans in people who still have some teeth (see "Accuracy limitations").
• The equipment and the laboratory. Scanners differ in accuracy, and not every clinic or laboratory works with scans.

Your dentist will tell you which method is planned for you and why, and which scanner is used if your teeth are scanned. You can ask for this in writing before you decide.

Your scan is a file

A scanner saves the model in its maker's own (proprietary) format, in an open format such as STL, or in both. The 2017 review stated that open-format files can be opened by all dental design (CAD) systems¹. Files from some closed systems can be opened only with software from the same maker¹, and converting files may lose quality and information¹. If another dentist may need your files later, check with them which format they can open. Ask for a copy in an open format and in the original format too.

How scans are stored and shared

A scan is a record of your mouth. Ask before treatment:

• whether your scan will be sent to a laboratory or anyone else, and where that laboratory is;
• how the files are sent and stored, and who can see them;
• how long they are kept, and how you can get a copy later.

Private dental clinics in Turkey record the diagnosis, the treatment and any X-rays in detail, with tooth numbers⁸. You can examine your file and records and get a copy⁹. Ask whether your scan files are included, and ask for the copies in writing.

Repeat scans

A scan records your mouth on the day it is taken. If a tooth is prepared or treated, teeth move or the gum changes, an older scan may no longer match. A new one is then taken. Because the scanner uses light, repeating a scan adds no X-ray dose.

Before treatment, you can ask:

• whether a scan or a conventional impression will be used, and why;
• which scanner is used, and whether the files can be exported in an open format such as STL;
• who takes and checks the scan, and who designs and makes the restoration, and where;
• what happens if a restoration does not fit, and who pays for a remake.

You have the right to be told, on request, who is treating you, and their role and title⁹. Ask for the answers in writing. Ask also for a written record of each restoration: the material, the product and the laboratory that made it.

Consent. Turkey's patient rights regulation says what you are told before treatment. It includes the other options, with their benefits and risks, and the possible consequences of refusing⁹. In private dental clinics, you are asked to sign a consent form for every intervention⁸. Two copies of the form are signed, and one is given to you⁹. Ask for your copy. You can say no, or ask to stop, at any stage. The scan itself removes nothing from your teeth, but once a tooth has been prepared (shaped) for a restoration, that step cannot be undone.