Accuracy of Different Surgical Guide Designs for Static Computer-Assisted Implant Surgery: An In Vitro Study

The aims of this study were to evaluate the effect of (1) the different surgical guide designs and (2) implant placement location on the accuracy of fully guided implant placement in single edentulous sites using an in vitro study model. Forty-five partially edentulous models were scanned and divided into 3 groups: group 1, tooth-supported full-arch surgical guide; group 2, 3 different tooth-supported shortened surgical guides (SSGs); and group 3, tooth-supported full-arch surgical guide with a crossbar. All surgical guides were printed and used for fully guided implant placement. A total of 180 implants (60 per group) were placed, and scan bodies were positioned on all models, and postoperative surface scan files (STL) files were obtained. Superimposition of preoperative and postoperative STL files was performed, and the accuracy of implant position was evaluated. The interaction between group and implant location was statistically significant for angle, 3D offset at the base, and at the tip (P < .001). The post-hoc tests showed a statistically significantly higher deviation for group 2 compared to group 3 for all outcomes for implants #4 (P < .05) and #7 (P < .05). There was also a statistically significant difference in all outcomes between groups 1 and 3 for implant #7 (P < .05). All surgical guide designs presented satisfactory performance with clinically acceptable levels of deviation. However, SSGs presented higher accuracy for guided implant placement in a single-edentulous site, whereas a full-arch surgical guide with a crossbar presented superior outcomes when 2 or more guided implants were placed simultaneously.