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The incorporation of computer-aided design/computer-aided manufacturing (CAD/CAM) technology into complete denture fabrication brings about several advantages to the fabrication process, providing better predictability of the desired outcomes and high accuracy of denture fit, mainly because the milling of prepolymerized acrylic resin eliminates the shrinkage of the acrylic base. Also, there is a decrease in the porosity when compared to a conventionally processed denture, and consequently there is a decrease in the retention of Candida albicans on the denture base. The presented workflow for complete denture fabrication presents a totally wax-free manufacturing process, combining rapid prototyping (RP) and rapid milling. With the presented technique, the maxillomandibular relation (MMR) and the ideal setup of the tooth arrangement are developed by using occlusion rims and trial setup made with RP. For the definitive final denture, the denture base and the basal surfaces of the conventional denture teeth were milled according to the individual clinical situation. Posteriorly, the teeth were adapted and bonded into the milled sockets of the milled base.

Background: The accuracy of implant casts generated with various impression techniques was mainly investigated in vitro resulting in limited clinical data. Purpose: (1) To compare the three-dimensional (3-D) accuracy of splinted and non-splinted impression techniques to the control casts (verification jigs) that had been used for actual patient treatment; and (2) to determine the maximum level of clinically undetectable misfit. The null hypothesis was that there would be no significant difference in the accuracy of casts generated with different impression techniques. Materials and methods: The implant casts used for the prosthetic rehabilitation of 12 edentulous jaws with CAD/CAM zirconia, implant-fixed complete dental prosthesis (IFCDP) were included in this study. Intraoral acrylic jigs were used to fabricate index casts. Splinted and non-splinted, open-tray techniques were used to generate two casts. Optical scanning acquisition of the x-coordinates, y-coordinates and z-coordinates of the implant positions for each individual cast was performed. The “best fit” algorithm was used with computer software to superimpose the scanning datasets. Group I (n=12) included casts from the splinted impression technique vs. acrylic jig casts, and group II (n=12) included casts from non-splinted technique vs. jig casts. Results: The paired t-test and Wilcoxon's signed ranks test were used to compare the 3-D discrepancies within and between groups I (splinted vs. jig) and II (non-splinted vs. jig), respectively. Significant difference was found at the x-axis, y-axis and 3-D between groups I and II (P 0.05). Within subject, global 3-D discrepancies between groups I and II were significantly different (P

The transition of patients from failing dentition to complete arch implant rehabilitation often requires that the patient be rendered edentulous and has to wear a complete removable dental prosthesis for varying periods of time. This is objectionable to many patients. A staged treatment approach allows a fixed interim restoration, patient comfort, and prosthodontic control throughout the rehabilitation process. CAD/CAM-guided flapless implant surgery has the advantage of prosthetically driven implant placement and minimal postoperative sequelae. A patient with a failing dentition was treated with this combined protocol and was followed up for 3 years after loading. Implant and prosthesis survival rates were 100%, with no technical complications encountered up to the last recall. The purpose of this clinical report is to describe a combination of CAD/CAM-guided flapless surgery and a staged treatment approach, thereby giving the patient a tooth-supported or implant-supported fixed interim prosthesis during the entire rehabilitation process. The various surgical, laboratory, and prosthetic stages are illustrated for the complete arch prosthetic rehabilitation, and the 3-year follow-up outcome is reported.

The effect of different implant impression techniques on the accuracy of casts has been investigated mostly in vitro, and clinically relevant evidence is scarce. The purpose of this study was to investigate the effect of implant impression techniques--specifically, splinted versus nonsplinted--on the accuracy of fit of fixed implant prostheses in edentulous patients.This clinical study included 12 edentulous patients (13 edentulous arches). All patients had undergone computer-guided, prosthetically driven implant surgery. Splinted (with acrylic resin) and nonsplinted pickup implant impression techniques were used to generate two different casts. Intraoral verification jigs were made to fabricate a third index cast (prosthesis fabrication cast); these made up a control group. All patients were definitively rehabilitated with one-piece zirconia prostheses. The accuracy of fit of each prosthesis was evaluated indirectly by examining them clinically and radiographically while they were fit on the generated casts.Of the 13 splinted casts, 12 presented with accurate clinical fit when the zirconia prosthesis was seated on its respective cast. Only 6 of the 13 nonsplinted casts showed accurate clinical fit. The zirconia prostheses fit accurately on all respective casts of the control group (prosthesis fabrication cast) as well as intraorally. The differences between the test groups and between the nonsplinted and control groups were statistically significant. No statistically significant differences were found between the splinted and control groups.There is clinical evidence that the splinted impression technique generates more accurate implant impressions and master casts than the nonsplinted technique for complete-arch, one-piece fixed prostheses.

The accuracy of implant casts generated with various impression techniques was mainly investigated in vitro resulting in limited clinical data.(1) To compare the three-dimensional (3-D) accuracy of splinted and non-splinted impression techniques to the control casts (verification jigs) that had been used for actual patient treatment; and (2) to determine the maximum level of clinically undetectable misfit. The null hypothesis was that there would be no significant difference in the accuracy of casts generated with different impression techniques.The implant casts used for the prosthetic rehabilitation of 12 edentulous jaws with CAD/CAM zirconia, implant-fixed complete dental prosthesis (IFCDP) were included in this study. Intraoral acrylic jigs were used to fabricate index casts. Splinted and non-splinted, open-tray techniques were used to generate two casts. Optical scanning acquisition of the x-coordinates, y-coordinates and z-coordinates of the implant positions for each individual cast was performed. The "best fit" algorithm was used with computer software to superimpose the scanning datasets. Group I (n=12) included casts from the splinted impression technique vs. acrylic jig casts, and group II (n=12) included casts from non-splinted technique vs. jig casts.The paired t-test and Wilcoxon's signed ranks test were used to compare the 3-D discrepancies within and between groups I (splinted vs. jig) and II (non-splinted vs. jig), respectively. Significant difference was found at the x-axis, y-axis and 3-D between groups I and II (P0.05), but not in the vertical z-axis (P0.05). Within subject, global 3-D discrepancies between groups I and II were significantly different (P0.05), corroborated by in vivo observations of clinical fit. Implant position in the arch affected the 3-D accuracy of casts for both anterior and posterior implants (P0.05).The splinted technique generated more accurate master casts than the non-splinted technique for one-piece IFCDPs in edentulous jaws and the null hypothesis was rejected. These clinical implications demonstrate improved accuracy of splinted impression techniques compared with the non-splinted technique. For the external connection, the implant system used in this study, a 3-D misfit ranging from 59 to 72 μm, may be considered the maximum discrepancy resulting in an acceptable clinical fit with one-piece IFCDPs.

Eight implants were placed in the posterior part of the mandible using computer-generated stereolithographic templates. Preoperative implant simulation was done on a 3D computer model created by reformatted computerized tomography data. The surgeon and the prosthodontist positioned the simulated implants in the most favorable position addressing all concerns with regard to anatomy, biomechanics, and esthetics. The length and diameter of each implant along with the angulation/collar of abutments required for a screw-retained prosthesis were determined. Stereolithographic templates were then fabricated by incorporating the precise spatial position of the implants within the bone as previously planned during the computer simulation. The templates were fabricated to seat directly on the bone and were stable. The first template was used to complete osteotomies with a 2-mm twist drill followed by the second template for the 3-mm drill. Implants were placed and allowed to integrate for 4 months. After second-stage surgery, the definitive abutments were torqued into place followed by insertion of the definitive screw-retained prostheses. Dimensions of all implants and abutments were the same as planned during the computer simulation. J Prosthodont 2006;15:117-122. Copyright C � 2006 by The American College of Prosthodontists.

Surgical and prosthodontic implant complications are often an inadvertent sequelae of improper diagnosis, planning, and placement. These complications pose a significant challenge in implant dentistry. Presented in this article is a technique using a highly advanced software program along with a rapid prototyping technology called stereolithography. It permits graphic and complex 3D implant simulation and the fabrication of computer-generated surgical templates. These templates seat directly on the bone and are preprogrammed with the individual depth, angulation, and mesio-distal and bucco-lingual positioning of individual implants as planned during the 3D computer simulation.