Accuracy of a computerized tomography-guided template-assisted implant placement system: an in vitro study

Objectives To evaluate the accuracy of computer-assisted 3D planning and implant insertion using computerized tomography (CT). Materials and methods Nine implants were planned on pre-operative CTs of six resin models, which were acquired with radiographic templates, using a planning software (E implants). Each resin model contained three pre-existing control implants (C implants). Radiographic templates were converted into operative guides containing 4.8-mm-diameter titanium sleeves. A single set of insertable sleeves was used for consecutively drilling the six models, followed by implant insertion through the guide sleeves. Models were further divided into group A (the first three models) and group B (the last three models). Post-operative CTs were used to compare implant positions with pre-operative planned positions. Statistical analysis included the Mann-Whitney U test for E and C implants and the Wilcoxon's signed ranks test for groups A and B. Results The mean apex depth deviations for E and C implants [0.49 mm +/- 0.36 standard deviation (SD) and 0.32 mm +/- 0.21 SD, respectively], and the mean apex radial deviations (0.63 mm +/- 0.38 SD and 0.49 mm +/- 0.17 SD, respectively) were similar (P > 0.05). The mean angulation deviations for E and C implants were 2.17 +/- 1.06 degrees SD and 1.33 +/- 0.69 degrees SD, P < 0.05. E implant deviations of all the parameters in group A were significantly smaller than E implant deviations in group B. Conclusions Computer-assisted implant planning and insertion provides good accuracy. Deviations are mainly related to system and reproducibility errors. Multiple use of drills and titanium sleeves significantly reduces system accuracy. To cite this article:Horwitz J, Zuabi O, Machtei EE. Accuracy of a computerized tomography-guided template-assisted implant placement system: an in vitro study.Clin. Oral Impl. Res. 20, 2009; 1156-1162.doi: 10.1111/j.1600-0501.2009.01748.x.