Intraoral and Laboratory Scanning Accuracy of Different Scan Body Designs

Methods:  Three Biodenta (Biodenta Swiss AG, Berneck, CH) SB designs were evaluated by placing bone level implants in acrylic edentulous jaw. Scan body design groups (SBG) were: SBG1. Fixture level, hybrid design- PEEK round shape with one axial flat surface, Ti abutment-implant connection, abutment screw; SBG2. Same as SBG1 but with 3 axial flat surfaces; SBG3. On titanium multiunit abutment (MUA)- PEEK round design engaging hex head of MUA, prosthetic screw. A D810 laboratory scanner (LAB) and Trios color (IOS), (3Shape, Copenhagen, Danmark) were used to scan the SB producing files with system’s software for comparison to manufacturer’s master design STL files. Convince™ Software (3Shape) system compared reference STL files against SB scans. Deviations from reference STLs were measured at 20 points on both SB buccal and lingual surfaces, means (sd) caluclated and charted for direction. SB was divided into 6 regions from top to bottom for comparisons.

Results: For both IOS and LAB, scans for SBG3 were about 18um longer while SBG1 and SBG2 scans were about 18-27um shorter than master STLs. Comparing scanning accuracy between LAB-IOS: For SBG1 IOS was superior at coronal and gingival; SBG2 LAB was significantly more accurate; SBG3 LAB was significantly more accurate. For LAB scanning, greater complexity of SB,  greater the scanning error.

Conclusions: Greater complexity of SB seems to increase scanning error for LAB while for IOS, SBG1 design with one flat surface had the lowest scanning error.