Accuracy of computer-guided surgery: A comparison of operator experience

Abstract

Statement of problem: Even though high-precision technologies have been used in computer-guided implant surgery, studies have shown that linear and angular deviations between the planned and placed implants can be expected.

Purpose: The purpose of this study was to evaluate the effect of operator experience on the accuracy of implant placement with a computer-guided surgery protocol.

Material and methods: Ten surgically experienced and 10 surgically inexperienced operators participated in this study. Each operator placed 1 dental implant (Replace Select) on the partially edentulous mandibular model that had been planned with software by following a computer-guided surgery (NobelGuide) protocol. Three-dimensional information of the planned and placed implants were then superimposed. The horizontal and vertical linear deviations at both the apex and platform levels and the angular deviation were measured and compared between the experienced and inexperienced groups with the independent t test with Bonferroni adjustment (α=.01). The magnitude and direction of the horizontal deviations were also measured and recorded.

Results: No significant differences were found in the angular and linear deviations between the 2 groups (P>.01). Although not statistically significant (P>.01), the amount of vertical deviation in the coronal direction of the implants placed by the inexperienced operators was about twice that placed by the experienced operators. Overall, buccal apical deviations were most frequent and of the highest magnitude.

Conclusions: When a computer-guided protocol was used, the accuracy of the vertical dimension (depth of implant placement) was most influenced by the operator's level of experience.

Copyright © 2015 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

Figures

Fig. 1

Partially edentulous (missing second premolars bilaterally) mandibular model with radiopaque teeth.

Fig. 2

Radiographic guide made of clear acrylic resin.

Fig. 3

Planning of implant position with NobelGuide software A, Buccolingual view. B, Mesiodistal view.

Fig. 3

Planning of implant position with NobelGuide software A, Buccolingual view. B, Mesiodistal view.

Fig. 4

Stereolithographic surgical template.

Fig. 5

Mandibular model with maxillary typodont mounted on mannequin head to simulate intraoral situation.

Fig. 6

Sequential osteotomy. A, Note flange on drill. B, Flange in contact with metal sleeve of surgical template to control depth of osteotomy.

Fig. 6

Sequential osteotomy. A, Note flange on drill. B, Flange in contact with metal sleeve of surgical template to control depth of osteotomy.

Fig. 7

A, Initial implant placement with surgical handpiece. B, Final implant placement with manual torque wrench at ≤ 45 Ncm.

Fig. 7

A, Initial implant placement with surgical handpiece. B, Final implant placement with manual torque wrench at ≤ 45 Ncm.

Fig. 8

Occlusal view of implants in position.

Fig. 9

Three-dimensional superimposition of planned (yellow) and placed (light blue) implants.

Fig. 10

Measurements of linear and angular deviations between planned and placed implants. A: Angular deviation between planned and placed implants PFO: Overall deviation at implant platform level PFH: Horizontal deviation at implant platform level PFV: Vertical deviation at implant platform level APO: Overall deviation at implant apex level APH: Horizontal deviation at implant apex level APV: Vertical deviation at implant apex level

Fig. 11

Overall frequency distribution of horizontal deviation in mesiodistal direction. M = mesial; D = distal.

Fig. 12

Overall frequency distribution of horizontal deviation in buccolingual direction. B = buccal; L = lingual.