In-vitro study on the accuracy of a simple-design CT-guided stent for dental implants.
OBJECTIVE
An individual surgical stent fabricated from computed tomography (CT) data, called a CT-guided stent, would be useful for accurate installation of implants. The purpose of the present study was to introduce a newly developed CT-guided stent with a simple design and evaluate the accuracy of the stent placement.


METHODS
A resin template was fabricated from a hog mandible and a specially designed plastic plate, with 4 metal balls inserted in it for radiographic recognition, was attached to the occlusal surface of the template. With the surgical stent applied, CT images were taken, and virtual implants were placed using software. The spatial positions of the virtually positioned implants were acquired and implant guiding holes were drilled into the surgical stent using a specially designed 5-axis drilling machine. The surgical stent was placed on the mandible and CT images were taken again. The discrepancy between the central axis of the drilled holes on the second CT images and the virtually installed implants on the first CT images was evaluated.


RESULTS
The deviation of the entry point and angulation of the central axis in the reference plane were 0.47±0.27 mm, 0.57±0.23 mm, and 0.64±0.16°, 0.57±0.15°, respectively. However, for the two different angulations in each group, the 20° angulation showed a greater error in the deviation of the entry point than did the 10° angulation.


CONCLUSIONS
The CT-guided template proposed in this study was highly accurate. It could replace existing implant guide systems to reduce costs and effort.
Department of Oral and Maxillofacial Radiology and Dental Research Institute, School of Dentistry, Seoul National University, Seoul, Korea.
Young-June
YJ
Huh
Bo-Ram
BR
Choi
Kyung-Hoe
KH
Huh
Won-Jin
WJ
Yi
Min-Suk
MS
Heo
Sam-Sun
SS
Lee
Soon-Chul
SC
Choi