Please activate JavaScript!
Please install Adobe Flash Player, click here for download
ePaper created 2017-10-13, 10:01:15 | version 1.38.0
A c c u r a c y o f c o m p u t e r - a s s i s t e d i m p l a n t p l a c e m e n t Fig. 1 Fig. 2 Fig. 1 Intraoral digital impression in the fully digital group. Fig. 2 Conventional impression, wax-up and scan model in the control group. studies, not allowing for a true sample size calcu lation. Hence, it was decided to publish preliminary results with 12 patients. Partially edentulous patient aged 18 years or older, able to sign an informed consent form and in need of an implant-supported fixed res- toration was considered eligible for this study. Any potential implant locations based on indi- vidual patient requirements were considered eligible in the present trial. No set location or group of locations was excluded. Patients were not admitted to the study if any of the following exclusion criteria were present: general medical contraindication to oral surgery (American Society of Anesthesiol- ogists [ASA] Physical Status Class III or IV), irradiation of the head and neck area less than 1 year before implantation, psychiatric prob- lems, alcohol or drug abuse, pregnant or nurs- ing, untreated perio dontitis, severe bruxism or clenching, uncontrolled diabetes, poor oral hygiene and motivation, and inability to com- plete the follow-up. The investigation was con- ducted according to the principles embodied in the Declaration of Helsinki of 1975 for biomed- ical research involving human subjects, as revised in 2008. All of the patients were informed about the nature of the treatment and their written consent was obtained. Data col- lection was designed to preserve patient ano- nymity. All of the patients received preoperative photo graphs, periapical radiographs or pan- oramic radiographs for initial screening and evaluation. The prosthetic-driven planning workflow started with taking a CBCT scan (CRANEX 3Dx, SOREDEX, Tuusula, Finland) of the enrolled patient, using a wax bite to separate the dental arches. The next step was to create a digital model, accomplished in two ways: the clinician used an intraoral scanner to create a digital impression (Fig. 1), or the clinician took a conventional impression and then scanned the impression using an extraoral scanner (Fig. 2). Patients were randomly assigned to undergo intraoral digital impressions (fully digital group) or conventional impressions (control group). In the fully digital group, a digital impression was taken using a CS 3600 intraoral scanner (Carestream Dental, Atlanta, Ga., U.S.). The dig- ital data (STL interface format) were imported into 3-D design software (exocad DentalCAD, exocad, Darmstadt, Germany) to realize a virtual wax-up according to the functional and esthetic requirements. In the control group, a polyether impression (Impregum, 3M ESPE, Seefeld, Germany) was taken with a customized tray (Diatray Top, Dental Kontor, Stockelsdorf, Germany). The impressions were poured with Type IV Gypsum (T6, Techim Group, Arese, Italy) and then the models were mounted in a fully adjustable articulator (PROTARevo 7, KaVo Dental, Biberach, Germany). Afterward, a dental wax-up was produced according to the func- tional and esthetic requirements. Finally, the master cast and wax-up were digitalized using a laboratory scanner (Sinergia-Scan, Version 2016 Plus, Nobil-Metal, Villafranca d’Asti, Italy). In both groups, the STL and DICOM data were imported into a 3-D software planning program (3Diagnosys, Version 4.2, 3DIEMME, Cantù, Italy). Then, the reprocessed surface extrapolated from the DICOM data (using a Hounsfield scale filter) and the surface gener- ated by the master cast scanning process or by the intraoral scanning process were merged 10 Volume 3 | Issue 3/2017 Journal of Oral Science & Rehabilitation