Developing of an Ultrasonic Vibration Assisted Orthodontic Brackets Debonding Tool

• Main Authors: Jhih-Han Wang, 王祉涵
• Other Authors: Yunn-Shiuan Liao
• Format: Others
• Language: zh-TW
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/91207630332905653351

碩士 === 國立臺灣大學 === 機械工程學研究所 === 104 === Nowadays, the dentists often use pliers to remove the orthodontic brackets, however the patients would feel uncomfortable due to the fierce force. It would lead to another problem which the ceramic brackets may be broken into pieces and cause harm to patients and doctors if you use pliers as the debonding tool. Someone uses ultrasonic bone scraper (SL4 instrument, Electro Medical Systems, Switzerland), which is used for winning autologous bone material during surgery, to debond brackets. The purpose of this research is to develope a new tool especially for debonding orthodontic brackets and aims to reduce the debonding force and not to damage the ceramic brackets. SL4 ultrasonic bone scraper was the basic design model because of its feasibility to debond brackets though it was not made for orthordotics originally. Solidworks Design Studies, Solidwork Simulation and Ansys FEM were used to find out the optimal design model and analyze the natural frequency, amplitude, stress of the structure. It was with the aid of many professors and dental clinics to develop these two new OBD (Optimal Bracket Debonder), OBD-1(toothless) and OBD-2(tooth).The debonding force, time requring, ARI, brackets and enamel conditions and temperatures variations will be discussed in the article. The light activated resins would show brittle characteristic after hardening by curing light. There is little or no gross plastic deformation before it fractures. The mode shape of OBD correspond to the opening mode in failure mechanics. The experimental results showed that OBD can remove brackets easily without damaging the ceramic brackets and enamels. It takes less than 1 second to debond each bracket with lower force. And the thermal energies are hard to transmit upon the surface of teeth so it won’t do harm to teeth. Compare to OBD-1, the OBD-2 can debond brackets with a lower force. The reason may be the saw tooth can increase the stress because of the smaller contact area. This would make it debond the orthodontic brackets more easily.