Purpose To evaluate the accuracy of three digitization methods for the maxillary dental arch. Materials and Methods A maxillary typodont with various tooth preparation designs was used as the reference model. The scanned data were classified into direct scanning (DS), cast scanning (CS), and impression scanning (IS) groups according to the techniques applied for digitization (n = 10/group). An intraoral scanner was used for the DS group. Impressions obtained with polyether impression material were scanned with a tabletop scanner for the IS group. For the CS group, the definitive casts fabricated from the obtained impressions were scanned with the same tabletop scanner. The accuracy (trueness and precision) of the produced virtual dental casts was evaluated with specialized software. The full‐arch and individual abutment deviations were measured with regard to root mean square error (RMSE) values. Data were analyzed with statistical software with an α0.33em=0.33em0.05. Results The RMSE values for both trueness and precision were lowest in the IS group, followed by the CS and DS groups, with statistically significant differences among the groups (p < 0.05). The trueness of individual abutments was significantly higher in the IS group than in the DS group. In addition, the trueness of individual abutments was affected by the location of the abutments in the DS group, whereas it did not differ between individual abutments in the CS and IS groups. Conclusions These findings suggest that the IS method is an accurate digitization technique for the creation of a virtual dental cast.

Purpose/Objectives Dental students experience difficulties during the transition from preclinical to clinical curriculum. In order to help the students to adapt to the clinical education programme, a simulated practice using patient‐based customised models was introduced in this study to prepare for their first clinical practice. Methods This study included 45 third‐year predoctoral students (D3 students) who were about to perform the preparation of a single crown abutment on their first patient. After practicing abutment preparation using simulated models and providing the actual treatment to their own patient, the students were surveyed to investigate their perceptions on the simulated practice using the 3D‐printed customised typodont model. The statistical analysis of the quantitative data and the thematic analysis of the qualitative data were conducted. Results Regarding this simulation, more than 80% of the students gave positive feedback on their practice of (a) operative positions and postures, (b) finger rest, (c) occlusal reduction, (d) axial reduction and (e) proximal reduction. Student responses on the open‐ended questions about how they perceived the usefulness of this simulation were categorised as “First clinical case,” “Patient‐based model” and “Realistic simulation environment.” In addition, a number of improvements of the simulation were also suggested by the students including the typodont and the manikin. Conclusions This study gives insights into the significance of simulated practice using patient‐based customised typodonts as a transitional education tool and its direction of development in the field of restorative treatments accompanied by irreversible tooth preparations.

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This study investigated the trueness of a digital implant impression according to the orientation of the implant scan body (ISB) and the scanning method. With the flat surface of the ISB facing either the buccal or proximal direction, the ISB was scanned using one tabletop scanner (T500) and three types of intraoral scanner (TRIOS 3, CS3600, and i500). The effects of differences in the scanning method and ISB orientation were assessed. Postalignment data were subsequently obtained with the abutments generated using a digital library, and superimposed with reference data using a best-fit algorithm, followed by root-mean-square error (RMSE) analysis. The RMSE was lower in the buccal groups (28.15 ± 8.87 μm, mean ± SD) than in the proximal groups (31.94 ± 8.95 μm, p = 0.031), and lower in the full-scan groups (27.92 ± 10.80 μm) than in the partial-scan groups (32.16 ± 6.35 μm, p = 0.016). When using the tabletop scanner, the trueness was higher when the ISB was connected buccally (14.34 ± 0.89 μm) than when it was connected proximally (29.35 ± 1.15 μm, p < 0.001). From the findings of this study it can be concluded that the operator should connect the ISB so that its flat surface faces the buccal direction, and attempt to scan all areas. Additionally, it is advantageous to connect an ISB buccally when using a tabletop scanner.