Accuracy of Computer-Assisted Dynamic Navigation as a Function of Different Intraoral Reference Systems: An In Vitro Study

Abstract

The aim of this in vitro study was to determine whether the process chain influences the accuracy of a computer-assisted dynamic navigation procedure. Four different data integration workflows using cone-beam computed tomography (CBCT), conventional impressions, and intraoral digitization with and without reference markers were analyzed. Digital implant planning was conducted using data from the CBCT scans and 3D data of the oral models. The restoration of the free end of the lower jaw was simulated. Fifteen models were each implanted with two new teeth for each process chain. The models were then scanned with scan bodies screwed onto the implants. The deviations between the planned and achieved implant positions were determined. The evaluation of all 120 implants resulted in a mean angular deviation of 2.88 ± 2.03°. The mean 3D deviation at the implant shoulder was 1.53 ± 0.70 mm. No significant differences were found between the implant regions. In contrast, the workflow showed significant differences in various parameters. The position of the reference marker affected the accuracy of the implant position. The in vitro examination showed that precise implantation is possible with the dynamic navigation system used in this study. The results are of the same order of magnitude that can be achieved using static navigation methods. Clinical studies are yet to confirm the results of this study.

Keywords: computer-aided surgery; computer-assisted; computer-guided surgery; dental implants; dynamic navigation; real-time tracking; surgery.

Figure 1

Surgical handpiece with camera attached.

Figure 2

Plastic model with fixed marker, in this example a model from Group A.

Figure 3

Implementing implantation under standardized laboratory conditions.

Figure 4

Registering the drill.

Figure 5

Overlay of the planned and actual achieved implant position using the treatment evaluation program function of coDiagnostiX software.

Figure 6

The angular deviations achieved by each process chain. No significant differences were observed between the process chains. Process chain B_1: CBCT without a reference marker and intraoral digitization with and without a reference marker. Process chain B_2: CBCT without a reference marker and conventional impression and extraoral digitization with and without a reference marker. Process chain C: CBCT without a reference marker and intraoral digitization without a reference marker.

Figure 7

The global 3D deviations at the coronal exit point achieved by each process chain. The 3D deviations at the coronal exit point are significantly different between the B-1 process chain and the A, B_2, and C process chains. Statistical significance was determined using the Mann–Whitney U test. The red lines indicate significant group differences.