- 著者
- Yoshiyuki Amari Toshiki Takamizawa Ryo Kawamoto Yasuhiro Namura Ryosuke Murayama Munenori Yokoyama Akimasa Tsujimoto Masashi Miyazaki
- 出版者
- Nihon University School of Dentistry
- 雑誌
- Journal of Oral Science (ISSN:13434934)
- 巻号頁・発行日
- pp.20-0420, (Released:2020-12-30)
- 参考文献数
- 33
- 被引用文献数
- 4
Purpose: This study investigated the influence of professional mechanical tooth cleaning (PMTC) pastes on the surface texture of different subject materials.Methods: Two one-step PMTC pastes, Clinpro Cleaning Paste for PMTC (CP) and PRG Pro-Care Gel (PG), and multiple-step PMTC pastes, Merssage Regular (MR), Merssagge Fine (MF), and Merssage Plus (MP), were used. For comparison, PMTC was performed using distilled water without paste (DW). The subjected materials used were bovine enamel (ENA) and dentin (DEN), a resin composite (FSU), and lithium disilicate (IEC). The prepared specimens were polished using a #2000-grit silicon carbide paper. PMTC was performed using a brush at 1,000 rpm for 15 s.Results: The surface roughness (Ra) values of the specimens before and after PMTC were measured by laser scanning microscopy. The Knoop hardness number (KHN) of the subjected material was obtained. The types of PMTC pastes and subject materials had a significant influence on the Ra values and KHN. For the majority of subject materials, the descending order of Ra values after PMTC was MR > MF > CP > PG > MP > DW. The descending order of KHN of the materials was IEC > ENA > FSU > DEN.Conclusion: Although one-step PMTC pastes appeared to be effective, it is important to consider the subject material during PMTC.
- 著者
- Masahiro Kondo Hirofumi Aboshi Masaaki Yoshikawa Ayano Ogata Ryosuke Murayama Masami Takei Shin Aizawa
- 出版者
- Nihon University School of Dentistry
- 雑誌
- Journal of Oral Science (ISSN:13434934)
- 巻号頁・発行日
- vol.63, no.1, pp.54-58, 2021 (Released:2020-12-23)
- 参考文献数
- 37
- 被引用文献数
- 14
Age estimation of unidentified bodies is important in forensic medicine and crime scenes. There is accumulating evidence that DNA methylation in the human genome isolated from body fluids changes with age. Most of the data have been obtained by pyrosequencing. In the forensic field, a simple, quick, and economical method is required to evaluate the age of various types of samples. In this study, an age estimation method based on methylation levels of DNA extracted from teeth using real-time methylation-specific PCR (MSP) was developed. The CpG island in the upstream region of ELOVL2, which is known as a validated biomarker in blood samples, was selected as a target site. The CpG methylation levels highly correlated with age (r = 0.843, n = 29). Age-related increase in DNA methylation levels was not affected by sex differences. In addition, the simple regression model based on methylation status of the CpG island exhibited moderate accuracy with a mean absolute deviation between chronological age and predicted age of 8.94 years. The results imply that real-time MSP can be a new tool to perform age prediction of unidentified bodies in forensic scenes.
- 著者
- Ryosuke Murayama Yuko Nagura Kabun Yamauchi Nobuyuki Moritake Masayoshi Iino Ryo Ishii Hiroyasu Kurokawa Masashi Miyazaki Yumiko Hosoya
- 出版者
- Nihon University School of Dentistry
- 雑誌
- Journal of Oral Science (ISSN:13434934)
- 巻号頁・発行日
- pp.17-0256, (Released:2018-07-09)
- 参考文献数
- 40
- 被引用文献数
- 5
We used optical coherence tomography to examine the effect of a coating material containing surface reaction-type pre-reacted glass-ionomer (S-PRG) filler on primary enamel demineralization in 18 extracted human primary teeth. The pulp was removed, and each tooth was ultrasonically cleaned with distilled water. Six teeth were treated with 0.1-M lactic acid buffer solution (De group). In the second group (n = 6), a thin film of coating material was applied before demineralization (PRG group). A third group (Control group; n = 6) was maintained in artificial saliva. Using optical coherence tomography, we measured peak signal intensity (dB) and width at 1/e2 (µm) at predetermined locations on the enamel surface and calculated integrated values. All data were analyzed with ANOVA and the Tukey-Kramer test (α = 0.05). Although changes in integrated values differed between groups, there was a small but significant increase in the Control group and a small but significant decrease in the De group. In the PRG group, integrated values were significantly higher at 7 days after the start of the experiment and significantly increased thereafter. Our findings indicate that a coating material containing S-PRG fillers may prevent primary enamel demineralization.
- 著者
- Chie KANAZAWA Ryosuke MURAYAMA Tetsuya FURUICHI Arisa IMAI Shunichi SUDA Hiroyasu KUROKAWA Toshiki TAKAMIZAWA Masashi MIYAZAKI
- 出版者
- 日本歯科理工学会
- 雑誌
- Dental Materials Journal (ISSN:02874547)
- 巻号頁・発行日
- pp.2016-175, (Released:2016-12-06)
- 参考文献数
- 28
This study used an ultrasonic measurement device to monitor the setting behavior of silicone elastomeric impression materials, and the influence of temperature on setting behavior was determined. The ultrasonic device consisted of a pulser-receiver, transducers, and an oscilloscope. The two-way transit time through the mixing material was divided by two to account for the down-and-back travel path; then it was multiplied by the sonic velocity. Analysis of variance and the Tukey honest significant difference test were used. In the early stages of the setting process, most of the ultrasonic energy was absorbed by the elastomers and the second echoes were relatively weak. As the elastomers hardened, the sonic velocities increased until they plateaued. The changes in sonic velocities varied among the elastomers tested, and were affected by temperature conditions. The ultrasonic method used in this study has considerable potential for determining the setting processes of elastomeric impression materials.
- 著者
- Mayumi KOTAKU Ryosuke MURAYAMA Yutaka SHIMAMURA Fuminori TAKAHASHI Takayuki SUZUKI Hiroyasu KUROKAWA Masashi MIYAZAKI
- 出版者
- 日本歯科理工学会
- 雑誌
- Dental Materials Journal (ISSN:02874547)
- 巻号頁・発行日
- vol.33, no.5, pp.648-655, 2014-09-30 (Released:2014-10-01)
- 参考文献数
- 33
- 被引用文献数
- 11
Effects of a fluoride-releasing varnish containing surface reaction-type prereacted glass ionomer (S-PRG) filler on dentin demineralization were examined using optical coherence tomography. Bovine incisors that were sliced and treated with undersaturated 0.1 M lactic acid buffer solution (DE group). A thin film of varnish-containing S-PRG filler was applied before demineralization (PRG group). Control was maintained in artificial saliva. Using optical coherence tomography of selected locations on the dentin surface, peak intensity (dB) and width (μm) at 1/e2 were obtained and integrated values calculated. Although alterations in integrated values were different in each group, there was a slight but not significant increase in those for the control group and a slight but significant increase for the De group. For the PRG group, integrated values were doubled seven days after experiment initiation, followed by a significant increase. Fluoride-releasing varnish containing S-PRG fillers prevented dentin demineralization as detected by optical coherence tomography.