Deep learning algorithms for identifying 79 dental implant types

Purpose@#This study aimed to evaluate the accuracy and clinical usability of an identification model using deep learning for 79 dental implant types. @*Materials and Methods@#A total of 45396 implant fixture images were collected through panoramic radiographs of patients who received implant treatment from 2001 to 2020 at 30 dental clinics. The collected implant images were 79 types from 18 manufacturers. EfficientNet and Meta Pseudo Labels algorithms were used. For EfficientNet, EfficientNet-B0 and EfficientNet-B4 were used as submodels. For Meta Pseudo Labels, two models were applied according to the widen factor. Top 1 accuracy was measured for EfficientNet and top 1 and top 5 accuracy for Meta Pseudo Labels were measured. @*Results@#EfficientNet-B0 and EfficientNet-B4 showed top 1 accuracy of 89.4. Meta Pseudo Labels 1 showed top 1 accuracy of 87.96, and Meta pseudo labels 2 with increased widen factor showed 88.35. In Top5 Accuracy, the score of Meta Pseudo Labels 1 was 97.90, which was 0.11% higher than 97.79 of Meta Pseudo Labels 2. @*Conclusion@#All four deep learning algorithms used for implant identification in this study showed close to 90% accuracy. In order to increase the clinical applicability of deep learning for implant identification, it will be necessary to collect a wider amount of data and develop a fine-tuned algorithm for implant identification.

Experience of Rh & Others Antigen Negative Rate Elicitation in a Blood Laboratory Center / 대한수혈학회지

BACKGROUND: The demand for Rh-related and other specific antigen negative donations has increased recently, and in response, we need to improve work efficiency while decreasing reagent consumption. Thus, we desire to create a ‘table of Nambu Blood Laboratory Center's own Rh-related and other antigen negative rate’. METHODS: We analyzed the results of Rh-related specific antigen test for 2,806,330 donors using ‘PK-7300’ and the results of manual test for 10,024 other blood type antigen-related specific and compound antigens. We made a table summarizing the results using two cases. RESULTS: The negative rate of Rh-related specific antigens was approximately 12.9% for C, 41.7% for c, 49.5% for E, and 9.2% for e antigens. The negative rate of compound antigens was increased when compared with the number of inspections. The negative rate for C and e antigens was increased from 90.1% to 97.3%, and that for E, c, and JKa was increased from 7.6% to 31.6%. CONCLUSION: The negative rate table made in July 2016 has been determined to be very effective in screening for specific and compound antigen negative blood. Also it was very efficient in terms of examining and supplying the compound antigen negative blood. It would be helpful to improve the supply of specific antigen negative blood to better meet the unique needs of each medical institution.

Accuracy of stone cast produced by adjustable dental impression tray / 대한치과보철학회지

PURPOSE: This study was performed to measure the accuracy of adjustable dental impression trays by a scanning laser three-dimensional digitizer. MATERIALS AND METHODS: The metal stock, individual, and adjustable stock trays were used for 60 stone casts(10 casts each) duplicated a resin master model of mandible and maxilla. The type IV dental stone was poured in a vinyl polysiloxane impressions and allowed to set for one hour. The master model and the duplicated casts were digitized using an optical digitizer. The distance between the reference points were measured and analyzed on the graphic image of 3-D graphic software(CATIA version 5.0). The statistical significance of the differences between the groups was determined by a two-way ANOVA. RESULTS: There were no significant differences between the accuracies of the adjustable stock tray and the master model except only anterior arch width on the upper arch and the diagonal arch length and arch length on one side of the lower arch. CONCLUSION: The adjustable stock trays showed clinically acceptable accuracies of the study cast produced by them.

A STUDY ON THE WEAR OF DENTAL RESTORATIVE MATERIALS / 대한치과보철학회지

The purpose of this study was to compare the wear characteristics of Type III Gold Alloy (Degular C; Degussa AG), VMK 95 (Vita Zahnfabrik), Vitadur Alpha (Vita Zahnfabrik), IPS Empress (Ivoclar-Vivadent) and Targis (Ivoclar-Vivadent). Ten samples of each material were abraded against enamel of extracted incisors for 160,000 cycles on the wear machine. The depth of wear scars on enamel was analized with profilometer (Alpha-step 200; Tencor). And the wear of material specimen was determined with micrometer (PB-1B; Mitutoyo Co. Japan). The results obtained were as follows : 1. Type III gold alloy (2.47micrometer) and Targis (5.89micrometer) caused less wear of enamel specimens compared to VMK 95 (75.59micrometer), IPS Empress (78.60micrometer) and Vitadur Alpha (78.89micrometer) (p<0.05). 2. The wear of material specimen when opposing enamel was the lowest in type III gold alloy (3.0micrometer), followed by Targis (69.8micrometer), IPS Empress (148.4micrometer). VMK 95 (298.0micrometer) and Vitadur Alpha (300.8micrometer) exhibited the most severe wear against enamel (p<0.05).