Comparison of functional and esthetic outcomes in digital versus analog rehabilitation of one-piece screw-retained implant crowns placed at second stage surgery.

PURPOSE: Analog and digital impressions are established procedures for restoration of single-tooth implants. In this study, single-tooth implants were restored with definitive restorations during second-stage surgery. Analog and digital workflows were compared. MATERIAL AND METHODS: Eighty single-tooth implants were examined in total. In 40 implants, an index was taken immediately after implant placement using composite resin to fabricate the final crowns (analog workflow). For the other 40 single-tooth implants, intraoral intraoperative scans were performed (digital workflow) during primary surgery. The custom-fabricated screw-retained crowns were placed during second-stage surgery. Photographs and examinations for the scores were taken at the time of the follow-up visit, 1-4 years after placement of the crowns. The number of treatment appointments required was recorded and the modified pink esthetic score (PES) was determined. Additionally, the functional implant prosthetic score (FIPS) was measured. RESULTS: The mean PES was 12.15/14 for the digital workflow and 11.95/14 for the analog workflow. The most common deficit was incomplete papillae for both workflows. Three treatment appointments were required for both workflows: (1) Scan and/or impressions making and patient consent, (2) implant placement, and (3) second-stage surgery with crown insertion. The FIPS was 9.1/10 for the digital workflow group and 9.2/10 for the analog workflow group. Common deficits presented as missing papillae as well as open approximal contacts. The FIPS was not significantly different between workflows (p = 0.679). The PES also did not show a statistically significant difference for both workflows (p = 0.654), however, the analog workflow showed better values for the papillae (p < 0.05). A significant difference was also found in the other PES values, with the digital workflow showing better results here (p < 0.05). A chronological analysis of the results of the digital technique showed that the cases treated last had significantly better values than the cases treated first. CONCLUSIONS: According to the results of this study, both workflows allowed placement of the definitive crowns on single-tooth implants during second-stage surgery. Both workflows were found to be equivalent in terms of esthetic results in this study, although the digital workflow demonstrated a learning curve.

Rehabilitation of one-piece screw-retained implant crowns placed at second-stage surgery-a retrospective patient series.

OBJECTIVES: To evaluate the esthetic and functional rehabilitation of single implants delivering the final crown during second-stage surgery. MATERIALS AND METHODS: In 26 single-tooth implants, the impressions were taken immediately after implant placement to fabricate the final crowns. During the second-stage surgery, the screw-retained hybrid crowns were delivered. Six months to 3 years after placement of the crown, a modified pink esthetic score (PES) was measured. Additionally, the number of treatment sessions was recorded. The mesial and distal contact points and the static and dynamic occlusion were examined. Patients' satisfaction was measured using a questionnaire. RESULTS: In this retrospective study, 21 posterior and 5 anterior implants were included. The average pink esthetic score was 11.3 out of 14. The most frequent limitations were incomplete papillae and deficits of the alveolar ridge. The average number of appointments was three, consisting of impression taking and surgery consent, implant placement, and crown delivery. Average patients' satisfaction was 46.7 out of 50 and thus, extremely high. CONCLUSIONS: The presented approach allows the second-stage surgery and delivery of the final restoration for single-tooth implants in the same session. As the peri-implant mucosa is adapted to the final restoration in the first place, a more natural emergence profile is achieved. However, there is an increasing risk for reduced or missing papillae. Patients' satisfaction is generally very high. CLINICAL RELEVANCE: A method for direct definitive prosthetic restoration during the exposure of single-tooth implants is examined, advantages and disadvantages will be described, and patient acceptance is validated.

Accuracy of a robotic system for the reproduction of condylar movements: a preliminary report.

OBJECTIVE: Methods in restorative dentistry have to meet stringent accuracy requirements. The accuracy of robotic systems used for the reproduction of condylar movements has not been determined. The purpose of this study was to assess the accuracy of the robot system, ROSY, a robotlike electronic simulator (developed by the author) that reproduces condylar movements previously recorded on a patient. METHOD AND MATERIALS: The simulator consists of a custom-designed ultrasonic system that records mandibular movements in all three dimensions (vertical, horizontal, and coronal) with six degrees of freedom. The simulator automatically reproduces all movements around these axes with a robotic system with six stepper motors. The accuracy of the simulator was measured for all directions in space by registering eccentric jaw positions on both sides of 10 subjects in two ways: (1) by the ultrasound registration system; and (2) simultaneously with an interocclusal recording medium. The standard deviation and interquartile range of the differences between the measurements based on these two approaches were used to statistically describe the accuracy of ROSY. RESULTS: The accuracy of the entire system was better than 0.28 mm. CONCLUSION: The electronic simulator comes with an accuracy that may render it suitable for clinical applications.

Accuracy of image-guided implantology.

OBJECTIVES: The accuracy of two commercially available systems for image-guided dental implant insertion based on infrared tracking cameras was compared with manual implantation. MATERIAL AND METHODS: Phantoms of partially edentulous mandibles were used. In a master phantom, pilot boreholes for dental implants were placed. These boreholes were reproduced in slave phantoms using either of the two image-guided systems and manual implantation. The resulting positions were determined using a coordinate measurement machine and compared with the master model. RESULTS: In comparison with manual implantation, the difference of borehole positions to the master phantom was significantly lower using either of the systems for image-guided implant insertion. CONCLUSION: Image-guided insertion of dental implants is significantly more accurate than manual insertion. However, the accuracy that can be achieved with manual implantation is sufficient for most clinical situations.