Accuracy Assessment of a Novel Milling Technique for the Fabrication of Computer Aided Surgical Stents

Purpose: The Target of this work was to compare the amount of both linear and angular deviation of the preplanned implants with the actually placed implants using this new milling technique for the fabrication of computer guided stents which aims to reduce accumulated errors and improve accuracy. Materials and Methods: This In-vitro study involved the construction of a total of twenty radiographic templates which were transformed into the Computer Aided Surgical Stent (CASS) by simply drilling the implant vector holes into the stent utilizing a CAD/CAM machine rather than using the rapid prototyping technology. Different types of deviations were recorded; the Apical Global, Coronal Global, Apical Vertical, Coronal Vertical, Apical Medio-Lateral, Coronal Medio-Lateral, Apical Antero-posterior and the Coronal Antero-Posterior deviation. Results: By using one sample t-test and hypothesized population mean = 0 for both Angular and linear deviations, it was revealed that there were significant differences for all implant deviations as P-value ≤ 0.001 for all the measurements. Conclusions: This technique successfully reduced the implant deviation in addition to eliminating expensive machinery for the computer guided stent fabrication thus saving time, material, energy and hence money