Accuracy evaluation of surgical guides in implant dentistry by non-contact reverse engineering techniques.
OBJECTIVE
In the paper laser scanning was used to evaluate, by indirect methods, the accuracy of computer-designed surgical guides in the oral implant supported rehabilitation of partially or completely edentulous patients.


METHODS
Five implant supported rehabilitations for a total of twenty-three implants were carried out by computer-designed surgical guides, performed with the master model developed by muco-compressive and muco-static impressions. For all cases the surgical virtual planning, starting from 3D models obtained by dental scan DICOM data, was performed. The implants were inserted on the pre-surgical casts in the position defined in the virtual planning. These positions were acquired by three-dimensional optical laser scanning and compared with the laser scans of the intraoral impressions taken post-operatively.


RESULTS
The comparison between the post-surgical implant replica positions and the positions in the pre-operative cast, for the five patients, shows a maximum distance in the range 1.02-1.25 mm, an average distance in the range 0.21-0.41 mm and a standard deviation in the range 0.21-0.29 mm.


CONCLUSIONS
The results of this research demonstrate accurate transfer of implant replica position by virtual implant insertion into a pre-operative cast and a post-operative cast obtained from impressioning. In previous studies the evaluation of the implant positions have required a post-surgical CT scan. With the indirect methods by laser scanning technique, proposed in the paper, this extra radiation exposure of the patient can be eliminated.
Giordano Dental Office, Caserta, Italy.
M
M
Giordano
P
P
Ausiello
M
M
Martorelli
D000328:Adult; D017076:Computer-Aided Design; D003758:Dental Implantation, Endosseous / Q000379:methods*; D017267:Dental Prosthesis Design / Q000379:methods*; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000295:instrumentation / Q000379:methods*; D007575:Jaw, Edentulous / Q000000981:diagnostic imaging* / Q000601:surgery; D007576:Jaw, Edentulous, Partially / Q000000981:diagnostic imaging / Q000601:surgery; D008297:Male; D018613:Microscopy, Confocal; D008875:Middle Aged; D003765:Models, Dental; D011859:Radiography; D025321:Surgery, Computer-Assisted / Q000379:methods