Facilitate™ is a computer guided planning tool for efficient, accurate and predictable implant treatment based on a 3D visualization of the patient's anatomy, including vital structures, implants, abutments and teeth. Facilitate is based on the successful SimPlant™ software from Materialise Dental™. The summaries present the Facilitate™ techniques and its advantages in various situations.
A prospective study on the accuracy of mucosally supported stereolithographic surgical guides in fully edentulous maxillae
A number of studies have demonstrated a discrepancy between the planned implant positions and those achieved in vivo. This has been shown to be due to a number of errors that can occur within the chain of data transfer from the virtual to the real world.
Purpose: To report on the accuracy of the Facilitate'" software offered by Astra Tech for the placement of Astra Tech OsseoSpeed1'1 implants in the edentulous maxilla using mucosally-supported stereolithographic guides.
Materials and Methods: Thirteen patients requiring implants for the rehabilitation of their edentulous maxillae were enrolled to the study. Patients were not excluded for smoking or other typically listed contraindications. At least 3 months after the extraction of the last standing teeth, impressions were taken of their edentulous jaws for diagnostic wax-up and subsequent fabrication of a full upper denture at the correct vertical dimension. This prosthesis incorporated small radiopaque glass spheres so that it could also act as a scanning template. A dual scan procedure was undertaken and the patient and prosthesis was reconstructed in 3 dimensions using the Facilitate software. Prostheti-cally driven virtual planning of 6 implants was carried out on the software and all implant lengths and widths were determined accordingly. In addition the location and orientation of at least 4 fixation screws was idealized. The resulting plan was sent to the manufacturer for the fabrication of the stereolithographic surgical guide to incorporate metal sleeves for drill guidance, depth control and subsequent implant placement. Implants were generally located 3 mm submucosally to allow for the establishment of the biologic width.
Intra-operatively the guides were fixed under local anesthesia by means of the fixation screws without flap elevation and osteotomies were prepared according to the drilling menu provided by the manufacturer to ensure correct dimensions and depth control. No tissue punch was used prior to drilling. All implants were inserted through the guide to a maximum torque of 50 Ncm. After guide removal standard Uni-Abutments" (Astra Tech) were connected and master impression taken for the conversion of the upper dentures into screw-retained fixed prostheses which were delivered within 8 hours.
Post operative CT scans were taken within 2 months and specialized software (Mimics 9.0, Materialise) was used to merge the virtual plan image with that of the actual implants in vivo. An iterative closet point algorithm was used to align the two images. The global, angular, depth and lateral deviation parameters were evalauated and compared for deviation between the two sets of images at both the coronal and apical ends of each implant. In addition the inter-implant distances were compared between the virtual and real post-op images. Statistical analysis was performed using SPSS software for non parametric analysis performed with the Kruskal-Wallis and Mann Whitney U tests. Differences were considered statistically significant if p< .05.
Results: One implant out of 78 placed failed to osseointegrated (1.3%) and no complications were reported with the use of the surgical guides. When comparing the virtual plan images to the actual postoperative images of the implants in vivo there were statistically significant deviations found for global apical position in 3 dimensions (mean apical deviation 1.13 mm), with 55% showing a deviation of > 1 mm. Although there was a coronal deviation of 0.91 mm this was not found to be statistically significant. Angular deviation varied from 0.16° to 8.86" with a mean of 2.6". Coronal inter-implant distance varied by only 0.18 ทาทใ compared to 0.33 mm for inter-implant distance measured at the apex.
Discussion and Conclusions: The deviations in the current study continue to reinforce the message that one cannot wholly rely on the use of stereolitho-graphic guides and virtual planning technology to deliver 100% accurate implant placement in 3 dimensions. However, the deviations reported in the current study are somewhat lower than has been reported previously. The small deviations in inter-implant distance suggest that deviations in apical location (in this study 0.33 mm) are the result of guide malposition rather than intrinsic errors within the guide or through drilling errors.
It can be concluded that within the confines of existing research, the Facilitate"1 software provides surgical guides which deliver acceptable accuracy compared to other published data on equivalent programs in particular when mucosally supported and secured by fixation screws. Clinicians need to be aware of the risk for angular deviations which give rise to linear apical deviations, which become accentuated for longer implants.
Astra Tech
BioManagement Complex 
