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en: Job shadowing for early undergraduate dental students: Validation of educational effectiveness using structural equation modeling

en: This study aimed to evaluate and validate the educational effectiveness of a job shadowing class as a dental teaching programme for preclinical dental students through a questionnaire that assessed related student perceptions. A total of 124 preclinical (second year) dental students at Tokushima University participated in job shadowing placements from 2017 to 2019. Each student observed dental practice or surgery for 1 day in the university hospital. After shadowing, the students were requested to fill out a nine-item questionnaire based on a five-point scale. The first analysis was performed to calculate the correlation for each item. Furthermore, regression analysis for the categorical data was performed to show the relationship between eight questions (Items 1-8) and one question (Item 9: comprehensive evaluation). Next, factor analysis was performed to determine students' perceptions regarding the shadowing class. Ninety-eight students (response rate: 79%) completed the questionnaire. There was a strong relationship amongst Items 1, 8 and 9 ("interested in dentistry as a job," "learning motivation" and "comprehensive evaluation" respectively) based on the results of the correlation and regression analysis. The factor analysis led to three student perceptions as latent factors, namely, "Interesting," "Self-awareness" and "Future Goal," which had a relatively close inter-factor correlation (0.465-0.772). The finding suggests that job shadowing may increase a students' interest in a dentistry career at an early stage of their education and learning motivation, along with generating self-awareness. This programme may present possible educational effectiveness in dental education.

en: European Journal of Dental Education

ja: European Journal of Dental Education


en: Possibility and Future of Intraoral Scanner Application to Change the Method of Taking Impressions

en: Journal of Oral Health and Biosciences

ja: Journal of Oral Health and Biosciences


en: Evaluation of the measurement precision and accuracy in the dental CAD/CAM system

en: The purpose of this study is to investigate the precision and trueness of the occlusal contact record obtained with a dental CAD/CAM device (ARCTICA). Sandblasted spherical steel balls with diameters of 10-20 mm were measured using ARCTICA and a three-dimensional measurement device (FN503). The radius of each steel ball was calculated from the measured value and the difference between the measured and nominal values was obtained. Upper/lower dental arch casts were measured and processed for occlusal contact image creation using both devices. The graphical images of the occlusal contacts at the intercuspal position obtained from both systems and an occlusal analysis device (BE-1) were compared with the occlusal contact area. Excellent correlation was observed between the measurement results of ARCTICA and FN503 (p<0.001, R: 0.99). The occlusal contact areas were 186.0 mm (ARCTICA), 192.8 mm (FN503), and 196.1 mm (BE-1). This study showed that ARCTICA is capable of conducting highly accurate measurements and generating a graphical image of occlusal contacts with good reliability.

en: Dental Materials Journal

ja: Dental Materials Journal


en: Educational effects using a robot patient simulation system for development of clinical attitude

en: The aim of this study was to assess the effectiveness of improving the attitude of dental students towards the use of a full-body patient simulation system (SIMROID) compared to the traditional mannequin (CLINSIM) for dental clinical education. The participants were 10 male undergraduate dental students who had finished clinical training in the university hospital 1 year before this study started. They performed a crown preparation on an upper pre-molar tooth using SIMROID and CLINSIM as the practical clinical trials. The elapsed time for preparation was recorded. The taper of the abutment teeth was measured using a 3-dimensional shape-measuring device after this trial. In addition, a self-reported questionnaire was collected that included physical pain, treatment safety and maintaining a clean area for each simulator. Qualitative data analysis of a free format report about SIMROID was performed using text mining analysis. This trial was performed twice at 1-month intervals. The students considered physical pain, treatment safety and a clean area for SIMROID significantly better than that for CLINSIM (P < .01). The elapsed time of preparation in the second practical clinical trial was significantly lower than in the first for SIMROID and CLINSIM (P < .01). However, there were no significant differences between the abutment tapers for both systems. For the text mining analysis, most of the students wrote that SIMROID was similar to real patients. The use of SIMROID was proven to be effective in improving the attitude of students towards patients, thereby giving importance to considerations for actual patients during dental treatment.


en: Relationship between Frontal/Lateral Mandibular Translations and Masticatory Movement Based on Evaluation of Occlusal Surface Motion

en:
Objective: This study aimed to clarify whether crown restorations with adjusted occlusal surfaces that were formed using frontal/lateral mandibular translations, functioned without interference during mastication.
Materials and Methods: In 10 adult volunteers who had healthy normal dentition, frontal and lateral border movement was measured during unilateral mastication and free mastication, using an ultrasound digital mandibular measuring system (ARCUS digma2). Additionally, precise impressions of the upper and lower dental arch were taken, and dental casts were made. These casts were measured using a CAD/CAM scanning system (ARCTICA). For the fabrication of crown restorations, the functionally generated path technique (FGP technique) was used on the monitor for the lower first and second molar. The movement of the opposite teeth on the occlusal surface during frontal and lateral border movement, during unilateral mastication, and during free mastication was considered the functional occlusal surface. The data of the functional occlusal surface generated by frontal/lateral mandibular translations and that of each of the masticatory functional occlusal surfaces were superimposed using three-dimensional data evaluation software (GOM). The difference between these surfaces was evaluated to determine the interference area, maximum interference difference, and average interference difference.
Results: Interference was present for all functional occlusal surfaces created by mastication as well as those determined by frontal/lateral mandibular translations. The average interference values, in order of free masticatory movement, habitual masticatory side, and non-habitual masticatory side, were as follows. Interference area: 167.5 ± 20.8 mm2, 121.9 ± 28.5 mm2, 144.6 ± 28.0 mm2; maximum interference distance: 345.0 ± 43.1 m, 189.0 ± 39.9 m, 309.0 ± 46.8 m; average interference distance: 130.0 ± 15.7 m, 64.0 ± 10.6 m, 130.0 ± 21.9 m. Statistically significant differences were found for the maximum interference distance and average interference distance (both p < 0.05).
Conclusions: The functional occlusal surfaces for each form of mastication demonstrated interference with the functional surface of frontal/lateral mandibular translations. Thus, crown restorations of which the occlusal surfaces were adjusted and formed by frontal/lateral mandibular translations may interfere with mastication.


en: Evaluation of School Dental Checkups in the Tokushima University Hospital Training Curriculum : Results of Questionnaire Survey for 10 Years

ja: 臨床研修プログラムにおける学校歯科健康診断研修の評価 10年間のアンケート結果から

en: The Journal of Japanese Dental Education Association

ja: 日本歯科医学教育学会雑誌


en: Durability of Bond Strength Between Titanium and two PMMAs

en: Reserach & Reviews: A Journal of Dentistry


en: 二酸化チタン塗布エナメル質への青紫色半導体レーザー照射の影響，漂白効果について

ja: 二酸化チタン塗布エナメル質への青紫色半導体レーザー照射の影響，漂白効果について

en: Annals of Japan Prosthodontic Society

ja: 日本補綴歯科学会誌


en: Carbon dioxide laser application enhances the effect of silane primer on the shear bone strength between porcelain and composite resin

en: The purpose of this study was to evaluate the effect of carbon dioxide laser irradiation on the performance of silane coupling agent as an adhesion promoter. The carbon dioxide laser used in this study was Opelaser 03S II, which irradiated the silane coupling agent applied on the adhesive surface of porcelain. Before and after thermal cycling, shear bond strength was measured using a universal testing machine. Without primer treatment, most of the specimens failed adhesively before reaching the end of the thermal cycling period. For the specimens irradiated with carbon dioxide laser after primer treatment, their shear bond strengths before and after thermal cycling were higher than those treated with primer only -with a significantly pronounced difference between these two groups especially after thermal cycling. Therefore, a combined surface treatment which involved silane application followed by laser treatment was feasible and efficacious for chairside porcelain repair.


en: CO2レーザー照射が象牙質の耐酸性向上に与えるあたえる影響 -フッ化物との併用について-


en: Effect of surface treatment with commercial primers on tensile bone strength of auto-polymerizing resin to magnetic stainless steel

en: International Chinese Journal of Dentistry


en: レーザー溶接による磁性アタッチメントキーパーの取り付け法 --- 吸引力と腐蝕の検討

en:
Purpose: Recently, laser welding has gained wide acceptance as a dental laboratory technique for bonding metals. We have previously reported a new technique for installing a magnetic keeper in the overdenture abutment coping using laser welding. In the present study, the influence of this technique on the attractive force and corrosion were evaluated.
Methods: A commercially-available magnetic keeper and dental casting Au-Ag-Pd alloy were used. Specimens were prepared by one of the following procedures: original magnetic keeper only, conventional cast-on technique and laser welding technique. Attractive force between thedental magnetic assembly and magnetic keeper was measured using a self-made measuring device. The results were analyzed using the one-way ANOVA test. The external and inner surface of magnetic keepers and cross sections of specimens were observed using metal and stereoscopic microscopes before and after immersion of the specimens in 0.9% NaCl solution for 21 days.
Results: There was no significant difference of attractive force between the conventional cast-on technique and laser welding technique. All of the specimens using the cast-on technique rusted in the corrosion test. Half of the specimens using the laser welding technique changed less, and no oxidized layer or corrosion was observed on the surface.
Conclusions: Installation of magnetic keepers using laser welding is useful for increasing both attractive force and corrosion resistance.

en: The Journal of the Japan Prosthodontic Society

ja: 日本補綴歯科学会雑誌


en: Shock Absorbability of High-Abrasion-Resistance-Posterior Resin Teeth

ja: 硬質レジン人工臼歯の衝撃緩衝能に関する研究


en: Addition of the Photo-cured Composite Resin for Crown to Abrasion-resistant Plastic Posterior Denture Teeth --- Effect of Surface Treatment on Bond Strength

ja: 硬質レジン歯への光重合型硬質レジンの添加について --- 表面処理が接合強さに及ぼす影響


en: Bond Strength of Silicone Rubber Impression Materials to Self-curing Resin

ja: シリコーンラバー印象材と常温重合レジンとの接着強さについて

en: Shikoku Dental Research

ja: 四国歯学会雑誌


en: Estimation of residual stress in dental porcelain by Laser-Raman spectroscopy

en: Dental Materials Journal


en: Effect of barium in porcelain on bonding strength of titanium-porcelain system


en: Effect of ion-exchange on fracture toughness and physical strength of dental porcelains

ja: 焼付用陶材のイオン交換法による強化と破壊力学特性に関する研究


en: Shock-absorbing Behavior of Soft Denture Liner --- Part 2 Influence of Lining Design on Shock Absorbability

ja: 軟質裏装材の衝撃緩衝に関する研究 --- 第2報 裏装法の違いが衝撃緩衝能に与える影響


en: Studies on Soft Denture Liner by using Viscoelastic Analysis --- Part 3. Effect of Viscosity of Soft Lining Materials on Stress Distribution in Denture Supporting Structures

ja: 粘弾性解析による軟質裏装材の有用性に関する研究 --- 第3報 軟質裏装材の粘性が床下組織の応力分布に及ぼす影響


en: A Basic Study on Pressure Distribution of Supporting Structures under Complete Denture --- Part 3. Influence of Occlusal Surface of Artificial Posterior Teeth on Pressure Distribution

ja: 全部床義歯床下組織の負担圧分布に関する基礎的研究 --- 第3報 臼歯人工歯の咬合面形態の差が負担圧分布に及ぼす影響


en: A case of preparing complete denture using duplicate denture

ja: 複製義歯を用いて上顎総義歯の新製を行った症例

en: 日本総合歯科学会雑誌

ja: 日本総合歯科学会雑誌


en: 新しい方式を用いた非接触式3次元形状計測機の開発

ja: 新しい方式を用いた非接触式3次元形状計測機の開発


en: Clinical Application of Laser in Dentistry

ja: 歯科用レーザーの臨床応用について


en: Effect of barium in porcelain on bonding strength of titanium-porcelain system.

en: The bonding strength to titanium, thermal expansion, and bending strength of glassy porcelain containing barium of 5, 10, and 15 mass% were estimated and compared with those of barium-free porcelain, to estimate the effect of barium content on bonding strength to titanium. The three different glassy porcelains containing barium were made by melting at 950 degrees C. The bonding strength of a commercial porcelain to titanium increased with the addition of barium. Bending strength and thermal expansion were not affected by the barium content. Therefore, the addition of barium to porcelain is effective for strengthening the bonding of porcelain to titanium.