Thomas H. Yoo
Julian Conejo
HOWARD P. FRAIMAN
| Thomas H. Yoo | Julian Conejo | HOWARD P. FRAIMAN |
Yoo, Thomas H.1, Conejo, Julian2, Fraiman, Howard P.1
1University of Pennsylvania School of Dental Medicine, Department of Periodontics
2University of Pennsylvania School of Dental Medicine, Department of Preventive and Restorative Sciences
With the advancement of digital technology, there is an increase in complete digitization of restorative workflow in implant dentistry for partially dentate patients. However, in completely edentulous patients, there is still more evidence needed to support the accuracy of fully digital workflow over conventional impression techniques. The objective of this study was to measure and compare the accuracy of full-arch conventional implant impressions and full-arch digital implant impressions with snap-on scan bodies that have dual function of scan body and conventional closed-tray impression copings.
Methods6 implants were placed into a model of a mandible and snap-on scan bodies were attached and measured with a high-resolution reference scanner. The data from this scan served as the control. Three impression techniques were performed: open-tray impression (Group 1, n=5), digital impression (Group 2, n=5), and closed-tray impression (Group 3, n=5). Open-tray and closed-tray impressions were poured with Type IV dental die stone. Digital impressions were materialized into carbon-printed models (Group 4, n=5). Snap-on scan bodies were attached to Groups 1, 3, and 4 and they were scanned with the same high-resolution reference scanner from the control group. All datasets (Group 1, 2, 3, and 4) were imported into an 3D inspection software (Cloudcompare) and were superimposed with the. STL dataset from the control. After superimposing the data, the overlapping pixel count was calculated within intervals closest to 0.
ResultsAvailable data was analyzed. The data from the superimposed control group and Group 1 (n=4) showed 89.41% overlap of the pixel count between distance interval of -2.57 and 2.23. Group 2 (n=5) showed 98.77% overlap between distance interval of -2.09 and 2.20. Group 3 (n=4) showed 70.78% overlap between distance interval of -3.85 and 3.65. Group 4 (n=1) showed 91.40% overlap between -2.86 and 2.77.
ConclusionBased on the initial data analysis of the superimposed .STL files, open tray impression and the digital impression techniques seem to be more accurate with higher percentage of overlapping pixel count concentrated around 0 in Group 1 and 4. Closed tray impression technique seems to be the least accurate, showing the lowest percentage of overlapping pixel count concentrated around 0.