In Vitro Comparison between Metal Sleeve-Free and Metal Sleeve-Incorporated 3D-Printed Computer-Assisted Implant Surgical Guides.

The present study aims to compare the accuracy of metal sleeve-free 3D-printed computer-assisted implant surgical guides (MSF group) (n = 10) with metal sleeve-incorporated 3D-printed computer-assisted implant surgical guides (MSI group) (n = 10). Implants of diameter 4.0 mm and 5.0 mm were placed in the left second premolars and bilateral first molars, respectively, using a fully guided system. Closed-form sleeves were used in teeth on the left and open-form sleeves on the right. The weight differences of the surgical guides before and after implant placement, and angular deviations before and after implant placement were measured. Weight differences were compared with Student's t-tests and angular deviations with Mann-Whitney tests. Cross-sectional views of the insert parts were observed with a scanning electron microscope. Preoperative and postoperative weight differences between the two groups were not statistically significant (p = 0.821). In terms of angular deviations, those along the mesiodistal direction for the left second premolars were significantly lower in the MSF group (p = 0.006). However, those along the mesiodistal direction for the bilateral molars and those along the buccolingual direction for all teeth were not significantly different (p > 0.05). 3D-printed implant surgical guides without metal sleeve inserts enable accurate implant placement without exhausting the guide holes, rendering them feasible for fully guided implant placement.