Accuracy of implant placement in the posterior maxilla as related to 2 types of surgical guides: a pilot study in the human cadaver.
BACKGROUND
The position of implants may have an effect on obtaining osseointegration without complications and on the outcome of the prostheses.


OBJECTIVE
The purpose of this study was to compare the accuracy of implant placement with computer-guided surgery and freehand surgery in the atrophic area of the posterior maxilla.


METHODS
Six human cadavers (Kennedy-Applegate class I) were included in the study. The specimens were randomly classified into 2 categories by using a computer: computer-guided surgery (n=3) and freehand surgery (n=3). Thirty-nine implants were planned with the software. Two types of surgeries were performed. The preoperative computed tomography data were matched with the postoperative computed tomography data by using voxel-based registration software. The position of the planned implants was compared to the actual position of the implants. A multivariate analysis was used for each variable (bone density, length of implant, implant angulation, and surgical technique) to evaluate the effect of these variables on the implant accuracy (α=.05).


RESULTS
The statistical tests (Kolmogorov-Smirnov bootstrap) found that guided surgery offered significantly better accuracy for the platform (P=.002), apex (P=.001), and angle (P<.001). However, the accuracy of the 2 methods was similar for the depth parameter (P=.186). The bone density did not influence the implant placement accuracy.


CONCLUSIONS
Computer-guided surgery was more accurate than a freehand approach for placing implants into bilateral edentulous zones in the posterior maxilla.
Associate Professor, Department of Prosthodontics, Dental Faculty, University of Lyon, Lyon, France. Electronic address: renaudnoharet@gmail.com.
Renaud
R
Noharet
Medical Imaging Manager, GRPD, Nobel Biocare AB, Sweden.
Andreas
A
Pettersson
Associate Professor, Department of Public Health, Dental Faculty, University of Lyon, Lyon, France.
Denis
D
Bourgeois
D001284:Atrophy; D015519:Bone Density / Q000502:physiology; D002102:Cadaver; D017076:Computer-Aided Design; D003758:Dental Implantation, Endosseous / Q000295:instrumentation / Q000706:statistics & numerical data*; D017267:Dental Prosthesis Design; D006801:Humans; D007091:Image Processing, Computer-Assisted / Q000379:methods; D021621:Imaging, Three-Dimensional / Q000379:methods; D007576:Jaw, Edentulous, Partially / Q000000981:diagnostic imaging / Q000601:surgery; D008437:Maxilla / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D010347:Patient Care Planning; D010865:Pilot Projects; D025321:Surgery, Computer-Assisted / Q000295:instrumentation / Q000706:statistics & numerical data*; D014057:Tomography, X-Ray Computed / Q000379:methods; D014584:User-Computer Interface