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.