Use of a surgical navigation system for CT-guided template production

The purpose of this study was to evaluate in vitro the accuracy of 2 methods for computerized tomography (CT)-guided template production via a surgical navigation system.

Oral implants were planned on CT scans of standard dental stone casts with integrated target pellets. Method 1 used the aiming device of the navigation system for direct positioning of 2-mm surgical bur tubes on the dental stone casts. In method 2, the aiming device was used to guide drillings into the dental stone casts, and the surgical bur tubes were indirectly positioned by metal rods inserted in the drill holes. In both methods the bur tubes were affixed in a resin template. The accuracy of the obtained templates was evaluated by postoperative CT scans using descriptive statistics and the Student t test (P < .05 considered significant).

The mean accuracy (normal deviation from the defined targets) of method 1 was 0.5 +/- 0.3 mm (max 1.2 mm; n = 56). Mean accuracy for method 2 was 0.6 +/- 0.3 mm (max 1.4 mm; n = 56). No significant difference was found between the maxillary and mandibular templates.

Conventional navigation systems already installed in many hospitals may be used for surgical template production. In contrast to intraoperative tool tracking, there is no need for patient tracking, and the planned implant axis can be rigidly secured as precisely as technically feasible with the help of an aiming device.

Both methods of bur tube positioning may represent a precise means for CT-guided template production.