Background: Digitalisation is an expanding field in dentistry and implementation of digital teaching methods in dental education is an essential part of modern education. Therefore, two digital training modules were implemented in the preclinical curriculum at the Justus Liebig University Giessen. The aim of this study was to assess the students’ perspective on the implementation with a questionnaire survey.Methods: Since the fall term 2017/18, students of the course of dental prosthodontics I attended the training module I, where they learned to use computer-aided learning (CAL) approaches for the digital analysis of tooth preparations. In training module II, students of the course of dental prosthodontics II learned how to manufacture a computer-aided design/computer-aided manufacturing restoration. After the completion of the training modules, all students starting with the fall term 2017/18 to the spring term 2019 were asked to fill in a questionnaire regarding the aspects of handling, didactic benefit, motivation, and overall assessment.Results: Students rated the implementation of digital aspects in teaching as positive in terms of handling, didactic benefit, and motivation, but gave preference to the assessment of the tooth preparations by dental instructors. In addition, students assessed the feedback from the faculty regarding tips and tricks better than the digital feedback. More than 90% of the students indicated that they could imagine using an intraoral scanner for treatment of patients in the dental office in future.Conclusions: The results of the present study revealed a positive perspective of students on the implementation of digital dentistry in the preclinical curriculum. However, difficulties with CAL systems were reported and most students preferred evaluation of preparation by dental instructors. Thus, CAL approaches offer an additional teaching method besides the traditional teaching of manual skills.

Peter Rehmann, Dr Med Dent/Katharina Orbach, Dr Med Dent/Paul Ferger, Dr Med Dent/Bernd W?stmann, Dr Med Dent: Purpose: This retrospective clinical study aimed to evaluate the long-term outcomes of clasp-retained, metal-framework removable partial dentures (RPDs) and their clasped teeth, the influencing factors on survival, and the type and number of repairs needed during the observation period. Materials and Methods: The study is based on a convenience sample of 52 patients who received 65 RPDs with a total of 207 clasped teeth. The mean observation period was 3.11 ? 0.29 years (maximum: 10 years). Patient gender, prosthesis location (maxilla/mandible), number and distribution (Kennedy class) of abutment teeth, and impact of a continuous follow-up program on a favorable outcome probability were analyzed. Statistical analysis was performed using the Kaplan-Meier method (P < .05) in combination with Cox regression analysis. Results: During the observation period, 9.2% of the RPDs ceased to function and 5.8% of the abutment teeth were extracted. Mean RPD survival time was 8.07 ? 0.66 years, with a positive outcome probability of 90% after 5 years. Prosthesis location was the only parameter that significantly (P < .05) impacted this probability. Conclusion: Overall, the high survival probability and low extraction rate of the abutment teeth reported in this study indicate that RPDs designed according to hygienic pronciples are clinically successful. Int J Prosthodont 2013;26:147?150. doi: 10.11607/ijp.2959

To measure the internal fit of the computer-aided designed/computer-aided manufactured (CAD/CAM) crowns, a new scanner-based chairside approach was investigated in patients, and the results were compared to the established silicone replica technique and a digital laboratory replica method. Thirty full-coverage crown preparations were included. Based on a digital impression with an intraoral scanner (IOS, Trios 3), three CAD/CAM measurement copings (‘COM’, resin composite; ‘ZIR’, zirconium dioxide; ‘NPA’, non-precious alloy) were fabricated for each tooth preparation. The internal fit of the measurement copings was analyzed with three different evaluation methods: IOS-based digital approach (D-IOS), digital replica method with laboratory software (D-GOM), and conventional silicone replica technique (CV-SR). The congruence between the determined target parameter of the 80-µm cement space and the actual measured internal gap was investigated. Statistical analysis was performed by ANOVA (p-value < 0.05). No significant difference was determined between the three evaluation methods. However, significant differences were observed for the three coping materials (p-value < 0.05), the single measurement position (marginal, axial, and occlusal fit) (p-value < 0.05), and the interaction between the coping material and the measurement position (p-value < 0.05). COM revealed the smallest internal gap, followed by ZIR and NPA. Regardless of the coping material, the occlusal gap was higher than the axial and marginal gaps. Furthermore, only the internal gaps of the marginal area almost matched the target parameter of 80-µm for the cement space. D-IOS is effective for measuring internal fit of single crowns in different clinical settings.

Peter Rehmann, Dr Med Dent/Anke Podhorsky, Dr Med Dent/Bernd W?stmann, Prof, Dr Med Dent: Purpose: This retrospective clinical study evaluated the long-term outcomes of cantilever fixed partial dentures (CFPDs) and the factors influencing their survival probability. Materials and Methods: The study is based on a convenience sample of 57 patients who received 71 CFPDs on a total of 176 vital abutment teeth. The mean survival time of the CFPDs was calculated using a Kaplan-Meier estimate. The following variables were analyzed as covariates of the survival function (logrank test, P < .05): sex, denture location, number and distribution (Kennedy Class) of the abutment teeth, dentition in the opposing arch (removable dentures, fixed partial dentures, or natural dentition), position of the cantilever unit (mesial or distal), and participation in follow-up visits. Results: The mean observation period was 3.2 ? 2.8 years (maximum 10.7 years). During the observation period, 22.5% (n = 16) of the CFPDs ceased functioning. The calculated outcome probability was 93.0% after 5 years and 84.5% after 8 years. The number of abutment teeth was the only parameter that significantly (P < .05) impacted this probability. Conclusion: The survival rate of CFPDs on vital abutment teeth is comparable to that of conventional fixed partial dentures. Thus, CFPDs on vital abutments are an acceptable alternative to removable dentures.