Development of new articulator with six degrees of freedom jaw movement replicating system

Research Project

Project/Area Number	13672039
Research Category	Grant-in-Aid for Scientific Research (C)
Allocation Type	Single-year Grants
Section	一般
Research Field	補綴理工系歯学
Research Institution	The University of Tokushima
Principal Investigator	NISHIGAWA Keisuke The University of Tokushima Dental Hospital, Assistant Professor, 歯学部附属病院, 講師 (10202235)
Co-Investigator(Kenkyū-buntansha)	MATSUURA Hiroki The University of Tokushima Dental Hospital, Research Associate, 歯学部附属病院, 助手 (10271082) SATSUMA Toyoko The University of Tokushima School of Dentistry, Research Associate, 歯学部, 助手 (80335801) YAMAZAKI Yukiko The University of Tokushima Dental Hospital, Dental Resident, 歯学部附属病院, 医員 (60332821) BANDO Eiichi The University of Tokushima School of Dentistry, Professor, 歯学部, 教授 (00014168)
Project Period (FY)	2001 – 2002
Project Status	Completed (Fiscal Year 2002)
Budget Amount *help	¥1,500,000 (Direct Cost: ¥1,500,000) Fiscal Year 2002: ¥1,500,000 (Direct Cost: ¥1,500,000)
Keywords	six degrees of freedom jaw movement / artiulator / FGP technique / crown / morphology of occlusal surface
Research Abstract	OBJIETIVE The purpose of this research is to develop a new articulator that performs dynamic replication of jaw movement in six degrees of freedom. METHOD A healthy adult volunteer (male, 31 years old) who palaned to have full cast crown restoration on his left side upper first molar was selected as the subject. Clinical procedures for tooth preparation and taking impression were performed according to the standard methods of Tokushima University Dental Hospital. After taking informed consent, jaw monement of the subject was measured with six degrees of freedom jaw tracking device (BS-3). The recorded jaw movements were attached on the abutment tooth of working model, and this model was fixed on the positioning stage of HEXAPOD. During replication of jaw movement, functional pathway of opposite tooth occlusal surfacewas carved on FGP wax above occlusal table. Functional core was taken from the occlusal table, and FGP srticulator was used for waxing up of full veneer crown. RESULTS AND DISCUSSION Jaw movement data that measured by BS-3 is accurate to level of 10 um for translation and 0.001 degrees for rotation. HEXAPOD can control positioning stage precisely at level of 0.5-1.0 um for translation and 1.0 arcsec (0.000278 degrees) for rotation, so complete replocation of the measured jaw movements could be performed. Since cast stone cast stone model dose not have elasticity due to the periodontal tissue, the model could be broken during closing phase of jaw movement. So we applied silicone rubber impression material as shock absorber for attaching upper cast stone model. It could be concluded that the new six degrees of freedom articulator was applicable for designing functional occlusal surface of dental prosthesis.