Accuracy of 3D printed scan bodies for dental implants using two additive manufacturing systems: An in vitro study.

This study compared the accuracy of implant scan bodies printed using stereolithography (SLA) and digital light processing (DLP) technologies to the control (manufacturer's scan body) Scan bodies were printed using SLA (n = 10) and DLP (n = 10) methods. Ten manufacturer's scan bodies were used as control. The scan body was placed onto a simulated 3D printed cast with a single implant placed. An implant fixture mount was used as standard. The implant positions were scanned using a laboratory scanner with the fixture mounts, manufacturer's scan bodies, and the printed scan bodies. The scans of each scan body was then superimposed onto the referenced fixture mount. The 3D angulation and linear deviations were measured. The angulation and linear deviations were 1.24±0.22° and 0.20±0.05 mm; 2.63±0.82° and 0.34±0.11 mm; 1.79±0.19° and 0.32±0.03 mm; for the control, SLA, and DLP, respectively. There were statistical differences (ANOVA) among the three groups in the angular (p<0.01) or linear deviations (p<0.01). Box plotting, 95% confidence interval and F-test suggested the higher variations of precision in the SLA group compared to DLP and control groups. Scan bodies printed in-office have lower accuracy compared to the manufacturer's scan bodies. The current technology for 3D printing of implant scan bodies needs trueness and precision improvements.

Influence of implant diameter on accuracy of static implant guided surgery: An in vitro study.

STATEMENT OF PROBLEM: Static guided implant surgery may be the most accurate method of implant placement to date. However, within the same guided implant system, whether accuracy is affected when placing a larger diameter implant that requires more drills than a smaller diameter implant is unclear. PURPOSE: The purpose of this in vitro study was to evaluate the influence of implant diameter on the angulation and 3-dimensional (3D) deviations of posterior single implant placement using static guided surgery. MATERIAL AND METHODS: A polyurethane dental cast was made with an edentulous site at the maxillary right first molar position. Identical implant planning for each of 3 dental implant diameters 3.3, 4.1, and 4.8 mm (Straumann BLT) were made, and surgical guides for each implant diameters were fabricated by stereolithography. Fifteen implants of each diameter (N=45) were placed in simulated casts. A scan body was placed and the cast was scanned using an intraoral scanner. The positional discrepancies of implant placement, including angulation as well as 3D implant cervical and apex area deviations, were compared with the planned position. Linear ANOVA single factor analysis (ɑ=.05) was used, and box plots were made. RESULTS: The ranges of angulation deviations for 3.3-, 4.1-, and 4.8-mm implants were 3.6 degrees to 6.0 degrees, 3.7 degrees to 7.7 degrees, and 3.1 degrees to 6.7 degrees, respectively. The ranges of 3D implant entry deviations of 3.3-, 4.1-, and 4.8-mm implants were 0.96 to 1.4, 0.85 to 1.72, and 0.89 to 1.78 mm, respectively. The ranges of 3D implant apex of 3.3-, 4.1-, and 4.8-mm implants were 0.63 to 1.21, 0.64 to 1.48, and 0.48 to 1.27 mm, respectively. No statistically significant differences were found in any of the 3 measurements: P=.67 for deviation in angulation; P=.27 for 3D implant deviation of entry; and P=.3 for 3D implant deviation of the apex. CONCLUSIONS: Implant diameters had no significant effect on placement deviations when a single posterior static guided surgery was used.