Fabrication of a quartz optical fiber tip for dental treatment with Nd:YAG laser—Proposal of a new process with TiO2 powder

In dental treatment with Nd:YAG laser beam, a quartz optical fiber is generally used to transmit the laser beam, which is irradiated to the hard and soft tissues for a caries treatment and a periodontal tissue excision. Since a normal optical fiber, which the laser beam comes out from the tip of the fiber, has difficulty irradiating to a narrow space and an inner root canal uniformly, it is effective to use a processed optical fiber tip from which is obtained a diffused and circumferential laser beam. In this paper, a new process to obtain these laser beams with TiO2 powder is proposed, and the characteristics and the performances of the processed optical fiber were investigated. An experimental instrument was developed to measure the energy partition radiated from the processed fiber tip, and the ratio of a straight beam, a sideways beam and heat generated by the absorption of the laser beam was measured in each condition. As a result, the ratio of an energy partition was controllable by changing the incidence parameter to process the fiber tip, and the processed fiber tip corresponding to the clinical purpose could be obtained. The parameters which affected the processability of the fiber tip were processing time and incidence laser energy. The prepared cavity with processed fiber on the enamel was influenced by a straight beam, and the removal of enamel to the depth direction was controllable by using the processed fiber.