Yukio Miyagawa

The Role of Genetic Factors in the Outbreak Mechanism of Dental Caries

OBJECTIVE The aim of the present study was to investigate the relationships between cariogenic bacterial infection and single nucleotide polymorphisms (SNPs) in candidate genes associated with dental caries, and to explore the factors related to caries in children. STUDY DESIGN Children aged 3 to 11 years were selected. Detection of cariogenic bacteria (Streptococcus mutans, Streptococcus oralis, Streptococcus sobrinus and Lactobacillus) from the plaque of each patient, and SNP analyses of five candidate genes (MBL2, TAS2R38, GLUT2, MMP13 and CA6) were performed using DNA isolated from buccal mucosal cells. The dental caries experience in primary and permanent teeth was determined using the decayed, missing and filled teeth (DMFT) index, and the effects of the observed factors on the DMFT value were analyzed by multiple regression analysis. RESULTS The results of the multiple regression analysis showed that the DMFT value significantly increased in the presence of S. mutans or S. sobrinus (p < 0.001), while the dmft/DMFT value decreased in the presence of nucleobase C in MBL2 (p < 0.05). CONCLUSION These results suggest that the MBL2 gene is related to the pathogenesis of dental caries.

Development of metal-resin composite for dental magnet keepers, Part 2: Optimum 4-META content.

Six kinds of experimental magnetic resin composites containing SUS447J1 stainless steel particles as filler were prepared. UDMA/MAA resin with an MAA mole fraction of 0.67 was used as the matrix resin. The effects of six levels of 4-META content (2, 4, 6, 8, 10, and 12 mass%) on the setting and flexural properties were studied. The metal filler content in each paste was 90 mass%. Although working time and setting time significantly diminished with the increase of the BPO and DMPT contents, both working time and setting time satisfied the ISO 4049 requirements for all experimental levels. Flexural strength and elastic modules significantly improved with the increase of 4-META content up to 10%. The optimum 4-META content necessary to develop better composite resins for magnetic attachment has been clarified.

Odontology receives an impact factor

received its fi rst impact factor, 1.833, according to Thomson Reuters Journal Citation Reports (JCR) 2008. The impact factor for Odontology ranked 21st among 55 JCR journals in the subject categories of dentistry, oral surgery, and medicine. In this way, Odontology is being recognized for the high quality of the peer-reviewed articles published in the journal. We would like to thank authors, reviewers, members of the editorial board, and the publisher for their support and dedication in maintaining a high standard for the journal. We are also grateful to The Nippon Dental University for its generous support of our biannual publication, which was inaugurated in 2009. Odontology will continue to be at the forefront in disseminating novel, highquality fi ndings of advanced work from many researchers and clinicians in dental science and related fi elds. We look forward to receiving your submissions and your comments. Odontology (2010) 98:1