- 著者
- Motohiro UO Tsukasa AKASAKA Fumio WATARI Yoshinori SATO Kazuyuki TOHJI
- 出版者
- The Japanese Society for Dental Materials and Devices
- 雑誌
- Dental Materials Journal (ISSN:02874547)
- 巻号頁・発行日
- vol.30, no.3, pp.245-263, 2011 (Released:2011-06-02)
- 参考文献数
- 106
- 被引用文献数
- 49 66
After the discovery of fullerene and carbon nanotubes, various carbon nanomaterials were discovered or synthesized. The carbon nanomaterials have remarkable properties, different from bulk materials with the same chemical composition, and are therefore useful for industrial applications. However, the toxicity of nanomaterials may also differ from that of the bulk materials; this difference poses a concern. The physical similarity of nanomaterials to asbestos has led to evaluations for toxicity by many researchers using various methods. In this review, we compile and compare the toxicity evaluations of each carbon nanomaterial.
- 著者
- Tool SRIAMPORN Niyom THAMRONGANANSKUL Chumphol BUSABOK Sushit POOLTHONG Motohiro UO Junji TAGAMI
- 出版者
- The Japanese Society for Dental Materials and Devices
- 雑誌
- Dental Materials Journal (ISSN:02874547)
- 巻号頁・発行日
- vol.33, no.1, pp.79-85, 2014-01-30 (Released:2014-02-01)
- 参考文献数
- 65
- 被引用文献数
- 27 68
The surface morphology and crystal structure change of dental zirconia after hydrofluoric acid (HF) etching were evaluated. Four groups of sintered zirconia specimens were 1) control group, 2) immersion in 9.5%HF at 25oC for 1, 2, 3, or 24 h, 3) immersion in 9.5%HF at 80oC for 1, 3, 5, or 30 min and 4) immersion in 48%HF at 25oC for 30 or 60 min. The specimens were evaluated under SEM and XRD. The SEM analysis revealed changes in surface topography for all the HF-etched zirconia specimens. The irregularities surface increased with increasingly longer immersion times and higher etching solution temperatures. The XRD analysis of the HFetched zirconia specimens revealed the presence of a crystalline monoclinic phase along with a tetragonal form. It was concluded HF can etch dental zirconia ceramic, creating micro-morphological changes. Tetragonal-to-monoclinic phase transformation was induced on the etched zirconia surface.
- 著者
- Akifumi TAKAHASHI Tomohiro TAKAGAKI Takahiro WADA Motohiro UO Toru NIKAIDO Junji TAGAMI
- 出版者
- The Japanese Society for Dental Materials and Devices
- 雑誌
- Dental Materials Journal (ISSN:02874547)
- 巻号頁・発行日
- vol.37, no.5, pp.734-739, 2018-09-27 (Released:2018-09-30)
- 参考文献数
- 23
- 被引用文献数
- 20
The effects of contamination and cleaning methods on bonding of self-adhesive resin cement to zirconia ceramics were examined. Airborne particle-abraded zirconia (Zpex Smile) specimens were divided into the following four groups: control (con), contaminated with saliva and cleaned with tap water (HS), cleaned with Ivoclean (IC), and cleaned with Multi Etchant (ME). The pretreated specimens were bonded using three self-adhesive resin cements, and tensile bond strengths were measured using a universal testing machine at a crosshead speed of 2 mm/min. Con and IC groups showed significantly higher bond strength than those of HS and ME groups. Separately, the surface chemical composition of the groups was determined using X-ray photoelectron spectroscopy (XPS). XPS revealed that the N/Zr ratio increased in the HS group but decreased in the IC and ME groups. Cleaning agents can improve the adverse effect of saliva contamination on zirconia, but this effect varies depending on the product.