2001 Fiscal Year Final Research Report Summary
Evaluation on the mechanical properties and biocompatibility of the FRP esthetic orthodontic wire for clinical application
Grant-in-Aid for Scientific Research (A)
|Allocation Type||Single-year Grants |
|Research Institution||Hokkaido University |
SATO Yoshiaki Hokkaido Univ. Grad. School of Dental Medicine Instructor -> 北海道大学, 大学院・歯学研究科, 講師 (00250465)
WATARI Fumio Hokkaido Univ. Grad. School of Dental Medicine Prof., 大学院・歯学研究科, 教授 (70158682)
YAMAGATA Syuichi Hokkaido Univ. Grad. School of Dental Medicine Instructor, 大学院・歯学研究科, 助手 (70292034)
YAMAMOTO Takaaki Hokkaido Univ. Grad. School of Dental Medicine Instructor, 大学院・歯学研究科, 講師 (40230560)
KOBAYASHI Masahiro Tiba Institute of Technology Asso. Prof., 工学部, 助教授 (20083868)
UO Motohiro Hokkaido Univ. Grad. School of Dental Medicine Asso. Prof., 大学院・歯学研究科, 助教授 (20242042)
|Project Period (FY)
1998 – 2001
|Keywords||FRP wire / orthodontic treatment / mechanical property / improved bracket / edgewise bracket / fictional property|
The evaluation on the mechanical properties and biocompatibility of the FRP esthetic orthocontic wire for clinincal appoication is the aim of this research. The results are as follows:
1. After the FRP wire have been immersed in mechanical properties through water immersion. The deactivating load and elastic recovery in s hysterisis loop decreased much after water immersion. To prevent this, Bis-GMA was coated by R＆D method. The FRP with this coating by the method of R＆D with dipping speed 1 cm/min., showed sufficient rtention of flesural load (D/L 60-80 %) and good elastic recovery even after 30 days.
2. To develop the FRP wires in combination with biocompatible CaO-P_2O_5-SiO_2-Al_2O_3 (CPSA) glass fibers and PMMA matrix by hot drawing method, a photo cure polymerization method was applied to form the rectangular timber with a sufficient torque force. The FRP wire using dental composite resin for matrix showed a torsional load of 1/2 of Ni-Ti wire. This showed that the fiber content mainly contributes to flexural load while the use of stigg materials for the matrix is much more effective for improbing torsional properties.
3. To avoid the shear force exerted by ligatures, improved brackets with various radius curvature were evaluated. The limit of deflection of the FRP wire and the recovery of the elastic properties improved with the larger radius curvatures. It was also clarified from ligated bending test that good elastic recovery and high load-retention could be obtained.
4. The frictional properties between orthodontic wires and brackets and frictional coefficients were obtained under conditions of single contact plane and double contact planes. The friction properties of FRP wire with brackets were similar to those of metal wires expect for the polycrystalline alumina bracket.
Research Products (18 results)