In the process of custom orthotic insole fabrication, “molding” is the crucial first step. For decades, traditional plaster molding techniques have dominated the field. However, with the rise of digital technologies, 3D plantar scanning devices are gradually replacing the old methods.
But is it really more accurate, faster, and better? Today, we will comprehensively compare the clinical data of both methods to help you see the full picture of this “old versus new” showdown.
1. Efficiency Comparison: Scanners Increase Efficiency by Over 80%
The traditional plaster molding process involves foot casting, waiting for hardening, demolding, cleaning, and model conversion. This entire workflow takes at least 30 to 45 minutes and heavily relies on the operator’s experience, with poor repeatability.
By contrast, using a 3D plantar scanner, the entire scanning and model generation process takes only 1 to 3 minutes. A single device can complete nearly 100 scans per day, significantly improving clinic throughput.
✅ Data Comparison:
Plaster molding: ~40 minutes per person
3D scanning: ~3 minutes per person
Time saved: approximately 92%
2. Accuracy and Consistency: Digital Models Are More Stable
The accuracy of plaster molds depends on factors such as operator skill, patient cooperation, and plaster temperature, resulting in considerable variability for repeated measurements on the same patient. On the other hand, 3D scanners maintain an error margin within 0.5mm and offer traceable data.
✅ Clinical Evaluation Results:
Repeat measurement error in flatfoot patients:
Plaster method variance: ±3.4mm
3D scanning variance: ±0.7mm
Data consistency is clearly superior with digital scanning.
3. Patient Comfort and Experience: Digital Is More User-Friendly
Many patients report that plaster molding requires them to stay still for a long time, with feet under pressure and a cumbersome process. The 3D scanning method only requires standing or sitting with the foot positioned comfortably. It is non-contact, non-invasive, and easy throughout.
This digital approach is especially considerate for children, elderly patients, and those with diabetic foot conditions.
✅ Satisfaction Survey:
Plaster molding satisfaction: 73%
3D scanning satisfaction: 96%
4. Post-Processing and Manufacturing: Digital Models Are Easier to Edit and Transfer
Traditional plaster molds cannot be archived or easily modified. In contrast, digital scans can be imported directly into CAD systems for insole design, allowing multiple adjustments and repeated use. This is particularly suitable for remote customization, batch modeling, and cloud sharing workflows.
Furthermore, when combined with CNC machining and 3D printing, the accuracy and efficiency of insole fabrication are greatly enhanced.
