Desempeños del alumnado de Educación Secundaria en la evaluación de una investigación científica en el contexto de la industria láctea

En este estudio se analizan los desempeños de estudiantes de 2.º, 3.º y 4.º de ESO (14, 15 y 16 años) que cursan la asignatura de Física y química, cuando evalúan el diseño de una investigación sobre un problema de precipitación identificado en la industria láctea. Los desempeños se examinan por separado para cada dimensión del diseño: identificación de la cuestión objeto de investigación, formulación de hipótesis, planificación de la investigación y selección del criterio de finalización. Para el análisis de resultados, se recogen sus propuestas, en las que han de estar desarrolladas las siguientes tareas: seleccionar la mejor opción, justificar su elección y modificar la opción alternativa para convertirla en correcta. Los resultados menos adecuados corresponden a las dos últimas dimensiones citadas.In this paper we analyse the performance of 8th, 9th and 10th grade students (14, 15 and 16 years old respectively), attending Physics and Chemistry lessons, when assessing the design of scientific research on a precipitation problem identified in the dairy industry. Students' performances are examined separately for each dimension involved in the design: identifying the issue to be studied, posing the hypotheses, planning the research and selecting the ending criterion. For the analysis, we collect participants' individual proposals, which have to include the following tasks: selecting the best option, justifying their choice and modifying the alternative option so that it will be correct. The less adequate results correspond to the last two dimensions

STUDIES ON NEWLY DESIGNED TOOTH SURFACE TREATMENTS FOR ADHESIVE COMPOSITE RESTORATION

Recently, problems have occurred frequently such as cervical and exposed dentin surface lesions or root caries and subsequent hypersensitivity because of further increase of the elderly population. This study was projected to devise a proper and simple treatment and materials for the adhesive composite restoration for such lesions. The 10-20Ca (10% citric acid containing 20% calcium chloride) solution was found to be a comparatively mild tooth surface conditioning agent and to be effective with a single application to both dentin and enamel. In addition, the use of the SA primer (3% N-methacryloyl 5-aminosalicylic acid in 80% ethanol) and the LVR (visible light-cured, 33% microfilled low viscous Bis-GMA resin) dramatically improved the adhesion and adaptability of the composite restoration in the saucer cavity at the cervical area

International human resource development in Japanese dental field

目的：歯学領域の国際的人材育成に関する情報収集を目的に本調査を実施した。 方法：日本歯科医学教育学会発行の『歯科医学教育白書』（計5冊）の国際交流に関するデータ，および2022年に日本歯科医学会連合が実施した調査をもとに，わが国の歯学領域における国際的人材育成のあり方について検討した。 結果：わが国の29歯科大学で学ぶ外国人留学生数は287名（2009年），325名（2012年），514名（2014年），766名（2017年），988名（2021年）と経時的に増加し，学士あるいは博士の課程を修めるアジア諸国出身者がいずれの年も90%以上を占めていた。一方，日本人教員等は概ね2年以内の期間，客員研究員，教員として海外留学しており，その留学先の90％以上が欧米諸国であった。 結論：この国際交流の相違点を踏まえ，各国の歯科保健医療状況の相互理解を進めていくことが，わが国の歯学領域における国際的人材の育成，延いては国際化推進に寄与すると考えられた

Clinical effectiveness of direct resin composite restorations bonded using one-step or two-step self-etch adhesive systems : A three-year multicenter study

The purpose of this multicenter clinical study was to compare the mid-term clinical effectiveness of direct resin composite restorations using one-step or two-step self-etch adhesives (1-SEAs or 2-SEAs). In total, 352 restorations of class I–V cavities and non-carious cervical lesions in vital teeth (1-SEAs; 52 cases, 2-SEAs; 300 cases) were placed at nine university hospitals and evaluated according to the modified USPHS criteria at baseline, and after 1, 2, and 3 years. The recall rates were 86.6% (1 year), 80.1% (2 years), and 62.2% (3 years). Two restorations failed due to fracture during the follow-up, and there was no significant difference in survival rates between 1-SEAs (97.6%) and 2-SEAs (99.4%). However, 2-SEAs exhibited significantly lower occurrences of discoloration, marginal discoloration, fracture, and plaque retention. Moreover, the subjects reported a significantly lower postoperative hypersensitivity and higher overall satisfaction at all evaluation periods if 2-SEAs were used

Evaluation of the Repolished Surface Properties of a Resin Composite Employing Structural Coloration Technology

Resin composites employing structural coloration have recently been developed. These resins match to various tooth shades despite being a single paste. To accomplish this, the filler and base resin are tightly bonded, which is thought to provide excellent discoloration resistance. Here, we investigated the surface properties of one of these resins, including the discoloration of the repolished surface. We developed an innovative in vitro method to adjust the repolished surface, in which structural degradation is removed according to scanning electron microscopy (SEM) observation rather than by the naked eye. The resin samples (20 mm (length) × 10 mm (width) × 4 mm (depth)) were manufactured using this resin material. After accelerated aging of the resin by alkaline degradation, the resin was repolished and the discoloration (ΔE*ab), surface roughness (the arithmetic mean roughness (Ra)), and glossiness (the 60° specular) were measured. SEM observation showed that the appearance of the bond between the organic composite filler and base resin on the repolished surface was different from that on the mirror-polished surface. This revealed that according to our in vitro method it was difficult to make the repolished surface structurally identical to the mirror-polished surface. Among the properties of the repolished surface, the degree of discoloration did not change despite the rougher and less glossy surface. It can be concluded that the factors that induce discoloration in this resin composite are independent of the surface roughness and glossiness