Mechanics of Nickel-Titanium RotaryInstrumentation Applied to Endodontic Treatment

• Main Authors: Shi-Ming Huang, 黃世明
• Other Authors: Weng-Pin Chen
• Format: Others
• Language: zh-TW
• Published: 2006
• Online Access: http://ndltd.ncl.edu.tw/handle/22764710715187115979

碩士 === 中原大學 === 醫學工程研究所 === 94 === Abstract Using the traditional Endodontic hand files to prepare root canal, though it can achieve more satisfactory cleaning and shaping, but more consuming time and need more skillful technique. However, inexperienced in operation usually cause the transportation, zipping, perforation and separation. In recent years, the Nickel-Titanium (Ni-Ti) alloy instruments have been used widespread, they have the advantages of the higher elasticity and a lot of researchers have also verified few complications during canal preparation. However, separation is still a concern with Ni-Ti rotary instruments and they have the risk of unexpected fractures. So, the purpose of this study was to investigate the fracture influence factor of Ni-Ti rotary instruments by using finite element analysis. Then lead to recommendations for preventing instrument separation and reduce its fracture risk. The analysis results can be used to estimate optimization prepare procedure and to provide suggestions for the instruments innovative designs. First, we used the cutting volume of root canal preparation to find ProTaper files major cutting region. The new-type instruments have been designed according to this result. The design concept of the new-type files is the cutting by stage and the alteration major cutting region. They don’t use region have been designed smooth curve, in order to reduce frictional force and avoid cutting excessively of Ni-Ti rotary instruments. Finally, we compared the mechanical behaviors of new-type files and ProTaper files, the results showed the new-type files have low stress in the root canal, the risk of fracture have been decreased and more efficiency of root canal preparation.