| The ceramic brackets have been the first chioce for the adult patients because of its color beauty. But the surfaces of brackets are irregular and the complex structure of the fixed orthodontic appliance, it is hard for the patients to keep well oral hygiene, which leads to the result that the dental plaque are accumulating on the area between the brackets and the teeth surface. This situation breaks the balance of the original oral microorganism, so the amount and kinds of oral microorganism have been changed. Those inhabited microorganism become activity in the pathopoiesia. The enamel demineralization, white-spot lesion and the gingivitis are the common noted situations in the clinic job. The relevant informantions showed that the prevance of white-spot lesion occured near the area can be up to 73%93% during the orthodontic treatmnet.There are many methods to prevent the above complications, such as regular mechanical cleaning, antibiosis rinses or mouthwash and fluoride toothpaste and so on. But these methods need the well cooperation of the patients, which have many disadvantages. The nano TiO2 is a n-type semiconductor material, which has antibiosis property under the ultraviolet ray. So this study modified the ceramic brackets on the basis of the above property so as to offer a new thought in preventing and solving the orthodontic complication.Objective: To clear and definite the physical and chemical property and the antibiosis under the visible light of nano TiO2-xNx ceramic brackets. Supplying a new method for preventing the clinical compliances such as enamel demineralization in the orthodontic treatment.Method:?1? On the basis of the normal ceramic brackets made in China, to prepare the nano TiO2-xNx ceramic brackets by Sol-gel method.?2? The crystal structure of nano TiO2-xNx ceramic brackets was analyzed by XRD; The morphology of nano TiO2-xNx was observed by using SEM.?3?The thin film and the attachment force of the basal were respectively measured by MET-4000 multi-functional material surface of experimental apparatus.?4?The thickness of the nano TiO2-xNx thin film was analyzed by spectroscopic ellipsometer.?5? The color changes of ceramic brackets that before and after coating film were evaluated through German VITA Easyshade Advance 4.0 photoelectric color comparator.?6? To evaluate the antibiotic performance of thin film ceramic brackets in the visible light by plate bacterial colony counting method.Result:?1?On the basis of the normal ceramic brackets made in China, we successfully prepared the nano TiO2-xNx ceramic brackets by Sol-gel method.?2?The results analyzed by XRD showed that the crystal structure of thin film was anatase type and well degree of crystallinity; The result of SEM showed that the morphology of thin film was uniform and compact, the particle was in the level of nano.?3? The binding force between the nano TiO2-xNx thin film and its basal –ceramic brackets was well, which could bear the normal outside force during the normal function.?4?The colorimetric result revealed that nano TiO2-xNx ceramic brackets that the color changes of ceramic brackets that before and after coating film were not obvious, which would not affect the original beautiful property of ceramic brackets.?5?The antibiotic result of plate bacterial colony counting method showed that the antibiotic rate of TiO2-xNx thin film ceramic brackets in the visible light was up to 92.9% and the antibiotic rate for Candida albicans was more than 75.6%.Conclusion:By using of the nano TiO2-xNx thin film successfully prepared by the sol-gel method on the ceramic brackets, the vitro antibiosis trial showed that the modified ceramic brackets had well antibiosis performance for the common oral pathogenic bacteria. |
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