This validation study aimed to compare intraoral scanners available in the Hungarian market based on objective and comprehensive parameters. The developed criteria are accessible on this page and are continuously updated with new intraoral scanners appearing on the market.

The examined intraoral scanners are provided to us by Hungarian distributor companies for a testing period, which typically lasts 1-2 weeks. The first step in the examination is training, which the distributor company always provides. We request that the distributor companies provide us with theoretical and practical education on the scanner they distribute for dental students and experienced dentists who participate in digital impression-taking during the examinations.

The evaluation of the IOSs is performed in four different ways.

Short description: Our documentation is compiled from information provided by the manufacturer, international literature, and observations during usage. This document is a brief, comprehensive document for a quick overview of the main features of the intraoral scanner. These documents are on our website under the “Intraoral Scanners” menu.

Summary Chart
The summary chart lists all the critical parameters that may influence users in selecting the intraoral scanner that suits their needs. The summary chart includes 21 unique characteristics that influence usage and indication and shows which properties are specific to the scanners.

Ergonomic Parameters
We will evaluate the ergonomic design of the intraoral scanners that were investigated. These parameters are of significant importance regarding user comfort due to their demonstrated impact on scanning accuracy. We measure the head circumference of the intraoral scanner’s head and its handpiece’s weight.

Model Scanning
Model scanning serves a dual purpose: firstly, we record and average the time required for scanning the models, and secondly, we export the resulting STL files for subsequent accuracy assessment using the Geomagic Control X software package. During the accuracy assessment process, the STL files generated by the examined intraoral scanners are compared to a reference model. This reference model is a highly precise digitized version of the original PMMA model, scanned with a laboratory-grade scanner (3Shape E3). We re-digitize the sample with the reference scanner before each examination to account for any potential deformations in the resin material over time since scientific studies have confirmed that resin materials can undergo deformation relatively quickly. We only record the “clean scanning time during impression-taking,” excluding data acquisition and post-processing times.

• In our study, one PMMA maxillary model was initially used during the in vitro testing (which included preparation for a solo crown, inlay cavity, and bridge). The model was scanned by three inexperienced dental students who did not have experience in impression-taking procedures. This simulates the scenario where a dentist begins using a new intraoral scanner in their practice. Each student performs 10 digital impressions.
• Our protocol was updated with more model scanning in September 2023. We examine a total of 7 different PMMA models, encompassing a variety of dental scenarios. These models include a study model, a model with crowded dentition, a prepared dentition model, a quadrant model, and three models containing Straumann implant analogs. The models with implant analogs inmate an all-on-six case on a maxillary model, an all-on-four case on a mandibular model, and a bridge case with three implants. The study model is scanned by three dental students ten times. Conversely, the other models – a model with a crowded dentition, a prepared dentition model, a quadrant model, and three models containing Straumann implant analogs – are scanned by experienced dentists with over three years of expertise in digital impression-taking, with ten scans per model. 

• The measured parameters for each sample are as follows:

  Study model:

  WHL (Whole Deviation): Average deviation of the entire dental arch.

  Crowded model:

  WHL (Whole Deviation): Average deviation of the entire dental arch.
  Accuracy measurement was performed on a segment cut from the right to the left.

  Prepared model:

  WHL (Whole Deviation): Average deviation of the entire dental arch.
  Accuracy measurements include:
  Prepared abutment of the upper right central incisor.
  Distance between the upper right first premolar and second molar.
  Distance between the distobuccal cusps of the upper last molars represents a distortion of the entire dental arch.

  Quadrant model:

  Accuracy measurement of the cavity prepared in the upper left first molar.

  Implant model 1 (Upper jaw, with 6 Straumann implant analogs):

  WHL (Whole Deviation): Average deviation of the entire dental arch.
  Five distances were measured between implant analogs: 16-14, 16-11, 16-21, 16-24, and 16-26 positions.

  Implant model 2 (Upper jaw, with 3 Straumann implant analogs):

  WHL (Whole Deviation): Average deviation of the entire dental arch.
  Two small distances were measured between implant analogs: 13-15 and 15-17 positions.
  One considerable distance measured between implant analogs: 13-17 position.

  Implant model 3 (Lower jaw, with 4 Straumann implant analogs):

  WHL (Whole Deviation): Average deviation of the entire dental arch.
  Four distances were measured between implant analogs: 33-43, 36-46, 33-36, and 43-46 positions.

• We divide accuracy results into old protocol (IOS tested before September 2023) and new protocol (IOS tested after September 2023).  The previous accuracy results include 27 intraoral scanner accuracy results, while currently, there are 9 intraoral scanner accuracy results based on the new protocol.

Clinical Scanning 
In vivo scans were also made by the three dental students. Each student performed 3 scans (totaling 9 impressions) of patients with full dentition. Full-arch study impressions were taken from the upper and lower arches by the examined IOS with bite registration in the intercuspal position. Similar to the model scanning process, we recorded and averaged the “clean scanning time” during impression-taking, excluding data acquisition and post-processing times. It’s important to highlight that a dentist (supervisor) with experience in digital impression-taking (both for model and clinical scans) was granted supervision during scanning.

Summary chart

• Remote Control: The scanner can be controlled through hand gestures or voice commands without touching the screen, which is advantageous for infection control.

Available Score: whether the examined IOS had a remote control (1 point) or not (0 points).

• Configuration: The configuration of the intraoral scanner refers to how the hardware can be accessed. It may be available in single or multiple configurations (e.g., cart, MOVE, pod versions, and integrable versions into the control unit). Dentists can choose the most suitable configuration for their practice.

Available Score: 0 points were awarded if an IOS was available in a single configuration, and 1 point was awarded if there was more than one configuration.

• Open vs. Closed system: CAD/CAM systems can be categorized based on the method of data transmission: open and closed systems. Closed systems restrict file processing to the manufacturer’s CAD and CAM software, while open systems allow scanning data to be processed by various CAD/CAM systems.

Available Score: Open system: 1 point, closed system: 0 points.

• Application: In terms of indications, there are 5 types: intraoral scanners suitable for treatment planning, implantology, orthodontics or prosthodontics, and systems ideal for chairside use. Each of the 5 applications scores 1 point. The dentist performs scanning, designs, and mill restorations in a single session using a chairside system in the chairside workflow. The manufacturer provides CAD/CAM software and milling and sintering units for a fully equipped chairside system. It’s important to note that points are only awarded for chairside use if the company offers a complete package, including the intraoral scanner, chairside design software, milling machine/3D printer, and furnace. For implantology, points are awarded if the examined intraoral scanner is compatible with implantology software, enabling implant and abutment positioning design or surgical guide creation. Orthodontic usage includes access to orthodontic software for software-based orthodontic analysis, treatment planning, or designing orthodontic appliances.

• Special properties: All features enabling the intraoral scanner to perform more than just digital impression-taking are listed. Tooth and prepared tooth shade selection (the scanner is equipped with a built-in spectrophotometer capable of determining tooth shade simultaneously with digital impression taking), detection of individual jaw movements (capability for dynamic occlusal registration), pre-preparation scanning option (scanning old/temporary restorations or the patient’s teeth before tooth preparation within a single workflow), dowel core scanning, impression scanning, denture workflow, smile design (smile design with dedicated software), different-sized scanner heads, and caries detection. Each mentioned feature is worth 1 point.

• Support: Annual license renewal means the user must pay a certain amount annually to continue using the intraoral scanner and transmitting STL files. Failure to do so would render the scanner unusable. Alternatively, unlimited support means no need for a renewed license contract or costs proportional to the number of cases.

Available Score: Annual license renewal, costs proportional to the number of cases: 0 points, unlimited support through purchase: 1 point.

• Infrastructure: During clinical use, dentists can contact the distributor or manufacturer via email/phone/in-person for questions and receive prompt responses. Any hardware or software issues encountered during servicing are reported to the manufacturer/distributor for a solution. If the scanner has a Hungarian service, problems can be addressed quickly without shipping the scanner abroad. If the distributor provides a replacement device within 24 hours, which remains with the user until their scanner is repaired, it receives the maximum score akin to local servicing.

Available Score: Foreign/online service: 0.5 points, domestic service/replacement within 24 hours: 1 point (maximum 1 point can be scored).

• Training opportunity: Training can be provided by the scanner’s local distributor in a designated location and time in Hungary. This includes assembly, software usage, and scanning strategy demonstration. Training can also be conducted abroad, but this usually incurs higher costs for dentists and is typically conducted in English. Domestic or foreign courses may also be supplemented with online training materials.

Available Score: 0 points if no training is available from the distributor, 0.5 points for foreign or online coaching, and 1 point for domestic training.

Ergonomic Parameters

• Weight of the handpiece (g): The weight of the scanner headpiece is measured three times, and the average is calculated.

• Circumference of the scanner’s head (mm): The circumference of the scanner head is measured three times, and the average is calculated.

Model Scanning

• Scanning Speed (s): The clean scanning time is measured from the beginning to the end of the scanning process. This time is recorded, averaged, and evaluated. Data acquisition and post-processing times are not included in the scanning time.

• Accuracy: The STL files generated by the examined scanners are compared to the STL files created by the reference scanner for all 7 samples. The most important results are the study model results, as they are scanned by dental students every time. The overall deviation of the entire dental arch and crowded samples are reviewed for the study. The parameters for the prepared tooth sample are examined: average deviations on the whole sample, average deviations on the selected prepared tooth, and distance measurements (short/medium/long distance and total arch distance). The accuracy of the 26 cavity preparations is examined in the quadrant sample. The overall deviation of the entire dental arch and the average deviations of the implant analog positions are compared to the reference for the implant samples.

Clinical Scanning

• Scanning Speed (s): The “clean scanning time” is measured from the beginning to the end of the scanning process. This time is recorded, averaged, and evaluated. Data acquisition and post-processing time are not included in the scanning time.

A photo protocol is one of the crucial steps in examining intraoral scanners, during which the same set of images is captured for each examined device. We take photos of the unpacking process of the intraoral scanner components, and part of the protocol involves sharing screenshots of both model and clinical scanning virtual models.