Accuracy, Labor-Time and Patient-Reported Outcomes with Partially versus Fully Digital Workflow for Flapless Guided Dental Implants Insertion-A Randomized Clinical Trial with One-Year Follow-Up

Abstract

(1) Background: Prosthetically-driven implant positioning is a prerequisite for long-term successful treatment. Transferring the planned implant position information to the clinical setting could be done using either static or dynamic guided techniques. The 3D model of the bone and surrounding structures is obtained via cone beam computed tomography (CBCT) and the patient's oral condition can be acquired conventionally and then digitalized using a desktop scanner, partially digital workflow (PDW) or digitally with the aid of an intraoral scanner (FDW). The aim of the present randomized clinical trial (RCT) was to compare the accuracy of flapless dental implants insertion in partially edentulous patients with a static surgical template obtained through PDW and FDW. Patient outcome and time spent from data collection to template manufacturing were also compared. (2) Methods: 66 partially edentulous sites (at 49 patients) were randomly assigned to a PDW or FDW for guided implant insertion. Planned and placed implants position were compared by assessing four deviation parameters: 3D error at the entry point, 3D error at the apex, angular deviation, and vertical deviation at entry point. (3) Results: A total of 111 implants were inserted. No implant loss during osseointegration or mechanical and technical complications occurred during the first-year post-implants loading. The mean error at the entry point was 0.44 mm (FDW) and 0.85 (PDW), p ≤ 0.00; at implant apex, 1.03 (FDW) and 1.48 (PDW), p ≤ 0.00; the mean angular deviation, 2.12° (FDW) and 2.48° (PDW), p = 0.03 and the mean depth deviation, 0.45 mm (FDW) and 0.68 mm (PDW), p ≤ 0.00; (4) Conclusions: Despite the statistically significant differences between the groups, and in the limits of the present study, full digital workflow as well as partially digital workflow are predictable methods for accurate prosthetically driven guided implants insertion.

Keywords: accuracy; digital impression; digital workflow; flapless; guided implant surgery.

Figure 1

Consolidated Standards of Reporting Trials (CONSORT) flowchart [13]. From the 55 enrolled patients, 6 were excluded due to lack of meeting the inclusion criteria. A total of 49 patients with 66 edentulous sites were randomly assigned to one of the protocols, either fully digital workflow (FDW) or partially digital workflow (PDW) (33 sites for each protocol). A total of 56 implants were inserted in 24 patients with FDW and 55 implants were inserted in 25 patients with PDW. No loss to follow-up patients was registered at one-year evaluation period.

Figure 2

Dental implants insertion planning in R2GATE software. (A) Importing digital or digitalized impression (standard tessellation language (STL) files) and cone beam computed tomography (CBCT) Digital Imaging and Communications in Medicine (DICOM) files; (B) Superimposing files using the “best fit” algorithm; (C) Design of the prosthetic restoration (digital wax-up); (D) Marking the alveolar nerve trajectory.

Figure 3

Planning implant directions, length and diameter in R2GATE software taking into consideration the final restoration and the available bone volume and quality. To facilitate bone quality assessment the “Digital Eye” option of the software (right) provides automatic conversion of CBCT gray scale in 5 basic colors, for bone density evaluation.

Figure 4

Study workflow: FDW—fully digital workflow, PDW—partially digital workflow including conventional impression, pouring models, models digitalization. Clinical steps are displayed in orange and laboratory steps are displayed in blue.

Figure 5

Precision assessment: S1 (digital scan at implant insertion) was compared with S2 (digital scan for final prosthetic manufacturing) in Geomagic Control X software. (A) 3D measurements at marginal border; (B) Angular deviation measurement.

Figure 6

Trueness assessment was performed 3D at the implant entry point (b’ vs. b), at the implant apex (a’ vs. a), angular deviation between the axes of the planned and effectively placed implant, and vertical deviation on z axis.

Figure 7

Trueness measurements in Geomagic Control X. (A) The displayed data were registered for assessment. (B) Measurement of angular deviation.

Figure 8

(A) 3D error at implant entry point overall and separately evaluated for maxilla and mandible; (B) 3D error at implant apex overall and separately evaluated for maxilla and mandible. (C) Angular deviation; (D) Vertical deviation at entry point. The boxplots symbols significance: box—interquartile range (IQR), ᵻ range within IQR, — median line, □ mean, ◊ outliners. Red plots are for FDW group and blue plots are for PDW group.

Figure 9

Assessment of response to the VAS questionnaire (0 meaning not satisfied at all and 10 meaning completely satisfied): Q1: How was your experience with data collection (dental impression)?; Q2: How was your experience with dental implants insertion?; Q3: How do you describe your postoperative discomfort considering pain, swelling, bleeding? The boxplots symbols significance: box—interquartile range (IQR), ᵻ range within IQR, — median line, □ mean, ◊ outliners. Red plots are for FDW group and blue plots are for PDW group. Most of the patients in FDW grouped scored 10 at Q1 (minimum 9) comparing to PDW (scores between 6 and 9). Dental implants insertion and postoperative patient’s feedback was favorable, for both groups (VAS score between 8 and 10).