Assessment of the effectiveness of intraoral scanning in patients with maxillary defects: a clinical study.

Aim: To evaluate the accuracy of the intraoral scanner (IOS) for obtaining digital scans of maxillary defects and adjacent tissues to fabricate obturator prosthesis.

Material and methods: Ten randomly selected patients who required an obturator prosthesis after maxillary resection underwent both conventional (CI) and digital (DI) impressions. CI was obtained using traditional methods, and cast models were prepared. The cast models were digitized using a reference scanner in standard tessellation language (STL) format. For Group DI, an intraoral scanner (Trios 5; 3Shape TRIOS®Copenhagen, Denmark) was used for digital scans and the virtual models were created. The data of both groups were analysed by superimposing predetermined points using unreversed engineering software (Geomagic GmbH, 3D Systems, Rock Hill, USA).

Results: No significant deviations from normality (P > 0.05) were found in the predetermined points of the residual hard tissue in the STLs. No interaction was observed between the hard tissue components and the impression techniques used. However, accuracy significantly varied between overlapped points in defect parts across the two impression methods (P= 0 .028).

Conclusion: The evaluation of IOS for digitally scanning maxillary defects shows that they are less effective than CI methods, performing adequately with shallow defects but facing challenges with deeper cavities. It is essential to advance these techniques and conduct clinical studies with larger patient groups to gain broader acceptance of DI methods for routine clinical use, particularly for deep defects.