A novel method for complex three-dimensional evaluation of intraoral scanner accuracy

Area of Science:

• Dental Technology
• Digital Dentistry
• 3D Imaging

Background:

• Complete-arch digital impressions are crucial for modern restorative dentistry.
• Accurate 3D model creation is essential for predictable treatment outcomes.
• Assessing distortion in digital impressions is vital for ensuring clinical reliability.

Purpose of the Study:

• To compare the accuracy of two established methods and one novel technique for measuring distortion in complete-arch 3D dental models.
• To evaluate the influence of different intraoral scanner (IOS) scan patterns on model accuracy.

Main Methods:

• Maxillary and mandibular models were scanned using an IOS with four distinct scan patterns.
• Three methods were employed to assess accuracy and distortion: mean surface deviation after complete arch superimposition, point-wise deviation after complete arch superimposition, and point-wise deviation after superimposition at the scanning origin.
• The novel method involved superimposition solely at the scanning origin for point comparison.

Main Results:

• Significant differences in measurement accuracy were observed among the three methods, irrespective of the arch or scan pattern.
• The method involving superimposition at the scanning origin showed the highest overall mean deviation between identical points.
• The novel method effectively identified local, tooth-specific variations and amplified errors extending from the scanning origin, demonstrating high sensitivity to scan pattern effects.

Conclusions:

• The novel method provides a more sensitive assessment of cumulative stitching errors in complete-arch digital scans.
• This technique is well-suited for detailed investigation into the impact of various scanning patterns on 3D model accuracy.
• The findings highlight the importance of scan pattern selection for minimizing distortion in digital dental impressions.