The Accuracy of Conventional Versus Digital Implant Impression Techniques

The study was a controlled clinical trial using cone-beam computed tomography (CBCT) imaging and flapless surgical technique to place implants. Cone-beam Computed Topography of the patients was taken by x-ray machine to create a DICOM file of the patient. Intraoral scanning to create STL Files of the patient arches. Each patient had undergone four impression techniques: Conventional impression I; Closed tray impression technique, Conventional impression II; Splinted Open tray impression technique, Digital impression I; intraoral scanning of readymade abutments and Digital impression II; intraoral scanning using scan bodies. To digitize the Conventional impressions I and II, the readymade abutment was screwed on the analogs of the resultant stone casts, followed by digital scanning. Using the scan body, the exact implant position was determined and the implants were added using a digital library. The custom abutment was fabricated on the implant replica with the same readymade abutment measurement. Using the inspection software, a custom abutment was superimposed on each readymade abutment in all the readymade abutment scanning data with the best-fit algorithm. Then the custom abutment was saved as a new STL file for comparison. The digital impression I was set as a reference in all the coming comparisons. The comparison was done from different data acquisition techniques by using inspection software between Digital impression I, Digital impression II; and finally, with the digitized STL of the Conventional impressions I and II.