| Summary: | 碩士 === 國立臺灣大學 === 機械工程學研究所 === 101 === In recent years, Ni-Ti rotary instruments are widely used in dental root canal treatment, the dentist will let Ni-Ti rotary instruments continued to rotate and in-depth dental root canal to clean the inside of therapeutic efficacy. Ni-Ti rotary instruments used in the dental pulp will cause fatigue fracture without warning due to continued rotation of alternating tensile stress and compressive stress. If Ni-Ti rotary instruments fracture in the tooth root canal, it will increase the difficulty of the treatment and also cause some unnecessary medical disputes. Some researcher conduct static measure of crack growth or fatigue fracture by way of stopping the rotation, but this method can’t provide a continuous-time and automatic measurement system, we can not use it in clinical.
This study proposed to investigate the sound from successive bending rotation and the variation of the vibration wave resulting from the scratch of cutting, with two brands of Ni-Ti rotary instruments which are Protaper F2 and Endo Wave under different radii of curvature, curvature angle and rotational speed. In this study, the sensing of sound is performed by the microphone and the sensing of the vibration wave is performed by two FBG (Fiber Bragg Grating) which are affixed to the metal block and the motor. The sensors can be used to monitor the dynamic fatigue fracture, and in comparison with time domain and frequency domain, hoping to foreknow and warn before the fracture of Ni-Ti rotary instruments.
Whether the microphone or the two FBG optical pathes of laser pump light source which are used separately or simultaneously, there are some examples which reach the achievements of supplying the physical meaning of warning, prolonging the operating time, and saving the medical resources.
Keywords: Dental root canal treatment, Ni-Ti rotary instruments, Fatigue fracture monitoring, Fiber Bragg Grating.
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