Introduction: Access cavity preparation is recommended from lingual surface on mandibular incisor, however it makes changes to the root canal form. The purpose of this study was to fabricate preparation guides (PG) for access cavity on mandibular incisor, and to compare changes of root canal curvature using PG. Materials and Methods: Ten mandibular incisors were used and divided in two groups: (1) Using PG and (2) Control (preparation from lingual surface). They were scanned by micro CT (ScanXmate-D100SS270, Comscan) and reconstructed by 3-D image processing software (TRI/3D-BON, Ratoc). At first, root canal curvature were measured for coronal half on labio-lingual images and mesio-distal images. Then, two horizontal cross-sectional images which were divided into three equal parts longitudinally were made from root canal images. A straight line which was passing through center of these images was defined as root canal axis. Guided hole was designed on extended root canal axis on PG. PG were made by 3-D printer (Nobel 1.0, XYZ Printing). Access cavity were prepared for two groups. After preparation, they were scanned by micro-CT. Root canal curvature which included access cavity were measured for coronal half on both images. Results: Before preparation, there was not root canal curvature. After preparation, root canal curvature was not observed in PGs and were shown in all control on labio-lingual images. There was not observed with root canal curvature on mesio-distal images. Changing of root canal curvature were 17.7 degree. These results suggest that changes of root canal curvature could be reduced by PG.
2014-now:Research associate in The Nippon Dental University. 2011-2014: Endodontics Resident in The Nippon Dental University. 2010: Internship in The Nippon Dental University Hospital. 2004-2009: Dental school in The Nippon Dental University. From resident, my research is to investigate root canal morphology on mandibular incisor by using micro CT. It was suggested that the complexity of root canal morphology due to bifurcation, curving of root canal and apical delta. However it had not lateral canal on mandibular incisor. I think my presentation study will be developed to multi-root teeth. Article: Taro NISHIDA, Ichiroh KATSUUMI. Analysis of root canal morphology in mandibular incisor using micro-CT. Jpn J Conserve Dent 2014; 58: 42-52
Nippon Dental University
My research is to investigate how to reduce eugenol in zinc oxide eugenol sealer, and influence of rotary endodontic files. We have a study to measure the physical property of the novel sealer that was developed. Novel root canal sealer had expansion. Articles: Munehiro Maeda, Toshifumi Ozawa, Ichiroh Katsuumi. Influence of cutting aspect on continuous use of NiTi orifice opener. Jpn J Conserve Dent 2014; 57: 58-66. Munehiro Maeda Shuuichi Hashimoto, Ichiroh Katsuumi. Release and chemical change of eugenol via calcium hydroxide paste from zinc oxide eugenol mixture. Jpn J Conserve Dent 2004; 47: 291-302.
2017-: Professor, Department of Endodontics in The Nippon Dental University, School of Life Dentistry at Tokyo. 2016-: President of Japan Endodontic Association. 2008-2017: Professor, Department of Endodontics in The Nippon Dental University, School of Life Dentistry at NIGATA. My research is to investigate consider to endodontic therapy for Immature permanent tooth. Article: M IGARASHI, C.R. Irwin, M. Locke, I.C. Mackenzie. Construction of large area organotypical cultures of oral mucosa and skin. J Oral Pathol Med 2003; 32:422-430.