Has digital impression technology fully surpassed traditional silicone rubber impressions? This remains a frequently discussed question in restorative dentistry. Extensive in-vitro and clinical studies now provide clear evidence-based guidance.
Single Crowns and Short-Span Restorations: Digital Equal or Superior
Multiple studies show that for single crowns and three-unit fixed bridges, the marginal fit of intraoral digital impressions is statistically comparable to silicone impressions - and in some research, digital impressions produce even smaller marginal gaps. Work by Mostafa and others found that chairside CAD/CAM crowns fabricated from digital impressions achieved the highest marginal adaptation.
Digital impressions eliminate several inherent sources of error associated with traditional methods:
Polymerization shrinkage of silicone materials (typically 0.1–0.5 %)
Gypsum expansion during model pouring
Wear of physical models during repeated handling
Long-Span and Full-Arch Restorations: Traditional Impressions Still Hold an Edge
As the length of the scanned arch increases, cumulative error in digital impressions tends to grow. Studies indicate that for restorations involving four or more implants or full-arch cases, the three-dimensional accuracy of silicone impressions currently remains superior. Traditional impressions capture all positional relationships in a single rigid tray, whereas intraoral scanning relies on sequential stitching; longer spans increase the risk of accumulated stitching error.
Implant Restorations: Case-Dependent
Single-implant and short-span implant cases: Digital impressions generally meet clinical accuracy requirements.
Complex full-arch implant reconstructions (e.g., All-on-4): Conventional open-tray impressions are still regarded as the gold standard.
Emerging intraoral photogrammetry (IPG) technology is progressively narrowing this gap.
Additional Comparison Dimensions
| Aspect | Digital Impression | Traditional Silicone Impression |
|---|---|---|
| Time efficiency | Full-arch scan typically 3–5 minutes | 20–30 minutes (including setting & disinfection) |
| Patient experience | No foreign-body sensation, minimal gag reflex; >80 % patient preference | Impression material and trays can cause discomfort |
| Repeatability | Data can be copied infinitely without loss of accuracy | Physical models wear with repeated use |
| Storage & transfer | Cloud storage and instant electronic transmission | Requires physical storage and logistics |
| Cost structure | Higher initial equipment investment; very low per-scan cost | Ongoing material costs accumulate |
Practical Conclusion for Clinics
In the majority of routine restorative situations - single crowns, short-span bridges, and simple implant cases - digital impressions are already a reliable and often preferable alternative to traditional silicone impressions. For complex long-span or full-arch implant reconstructions, combining digital scanning with conventional techniques or adopting photogrammetry-assisted methods is currently the most prudent approach.
The Aident AI-30 Intraoral Scanner delivers ≤10 μm accuracy, powder-free true-color scanning, 20–25 mm ultra depth of field, and ≥30 frames per second, helping clinics achieve efficient, patient-friendly digital impressions for everyday restorative and implant workflows. Its open STL/PLY/OBJ output further ensures seamless collaboration with any laboratory or CAD system.
Digital impressions have matured to the point where they can replace traditional methods in most clinical scenarios while offering clear advantages in speed, comfort, and data management. Choosing a high-performance open system allows practices to maximize these benefits today and remain adaptable for future advances.
Explore the Aident AI-30 and complete digital dentistry solutions at https://www.aident3d.com/, or request a quote to evaluate digital impression accuracy and efficiency in your own clinic.
