Fully-guided versus conventional implant placement by dental students. A randomized controlled trial

WFM9T ORAL COMMUNICATION CLINICAL RESEARCH – SURGERY

Background: For experienced clinicians, fully-guided implant surgery could lead to higher accuracy than conventional surgery. The benefit of digital guidance for implant surgery by dental students is unknown. Accuracy is documented as 3D measures of the global distance and angular deviation between the virtually planned and actual implant position. The clinical applicability of these variables may increase if additional information was reported, i.e. direction of deviation from the ideal implant position.

Aim/Hypothesis: The aim of the study was to compare the accuracy of fully-guided implant surgery with conventional implant surgery performed by dental students, in which the actual implant position is compared with an ideal, virtually planned implant position.

Materials and Methods: Twenty-five patients in need of straightforward implant-supported single crowns were randomly allocated to a fully-guided (T, n = 13) or a conventionally guided (C, n = 12) implant surgery. Pre- and postoperative CBCT scans (field-of-view: 5x5 cm) were obtained for all patients. In the T-group, surgical guides were produced based on CBCTs and optical scans of the implant quadrant imported into a dedicated software. In the C-group, surgical guides were produced based on wax-ups on stone models. In the preoperative CBCTs, 3 experts placed a virtual implant in the ideal position twice, allowing accuracy analysis in the coronal (facio-lingual) and sagittal (mesio-distal) planes. Coronal Crestal Deviation, Coronal Apical Deviation, Coronal Angular Deviation, Sagittal Crestal Deviation, Sagittal Apical Deviation, Sagittal Angular Deviation and Vertical Deviation between the ideal, virtually planned position and actual implant position for the T- and C-groups were compared statistically (P < 0.05)

Results: Intra- and inter-examiner correlation coefficients ranged from moderate to excellent, for all investigated parameters. The Coronal Crestal Deviation, Sagittal Crestal Deviation, Sagittal Apical Deviation, Sagittal Angular Deviation and Vertical deviation between the virtually planned and actual implant position were not significantly different in the T-group versus C-group. Statistically significant differences between ideal and actual position were seen for both the Coronal Apical Deviation (C-group, mean: 1.62 mm, SD: 0.62; T-group, mean: 1.21 mm, SD: 0.46; P = 0.047) and for the Coronal Angular Deviation (C-group, mean: 6.42o, SD: 4.21; T-group, mean: 3.35 o, SD: 1.65; P = 0.019), where the C-group deviated more from the ideal position compared to the T-group. The deviation of the C-group was primarily in the facial direction.

Conclusions and Clinical Implications: The fully-guided implant surgery performed by dental students did not significantly improve the accuracy of implant placement compared to conventional guided implant surgery. However, conventional guided implant placements by dental students tended to deviate more in the facio-lingual than in the mesio-distal plane. This method documenting deviations in implant position in the facio-lingual and mesio-distal planes may prove more clinically applicable than previous measures of 3D global deviation

Keywords: Accuracy, dental implants, Guided surgery, computer planning.