【作者】 倪冰；

【导师】 曹军； 赵信义；

【作者基本信息】 第四军医大学 ， 口腔临床医学， 2010， 硕士

【摘要】 固定正畸已成为目前矫治错牙合畸形最有效、应用最广泛的方法,然而,由于固定矫治器的戴入,改变了口内环境、增加了刷牙的难度,同时由于治疗时对牙面的酸蚀、患者刷牙不认真等原因,造成了固定正畸治疗中黏接托槽牙面牙釉质出现脱矿的问题,且这种情况具有较高的发病率。这种脱矿可导致牙面出现白垩斑或形成龋洞,影响了患者的牙齿健康、美观以及患者的满意程度。因此,如何预防正畸治疗中黏结托槽牙面牙釉质脱矿已经成为广大正畸医生不断讨论并尝试解决的问题。FQ光固化防龋涂料是第四军医大学口腔医院自主研发的一种光固化甲基丙烯酸树脂,具有固化前流动性好、可行薄层涂布、固化后无色透明、对牙面美观无明显影响等特点。本研究中我们用这种涂料在体外离体牙上对黏结托槽的牙面进行了封闭,然后对封闭后牙面的美观性、抗脱矿性能、与正畸托槽的黏结强度以及涂布的厚度和耐磨耗性等诸多指标进行了测试,以期能建立一种基于FQ光固化防龋涂料应用的、具有可行性的牙面封闭法预防黏结托槽牙面脱矿的途径。实验一:FQ光固化防龋涂料封闭层对离体牙外观效果的影响研究。用FQ光固化防龋涂料对离体牙进行表面封闭,置于自然光下观察其表面形态,对照封闭前的情况,比较分析这种非封闭方法的应用对牙齿表面美观形态的影响。将封闭后的离体牙进行MicroCT扫描及相应软件分析,测评其涂布厚度。结论:涂料层呈无色透明的隐性薄层,对牙齿表面形态美观无明显影响,且能够均匀分布于牙面。实验二:FQ光固化防龋涂料封闭法预防牙釉质脱矿的实验研究。将6颗离体前磨牙随机分为对照组和实验组,对照组常规清洁后不做处理,实验组颊面采用FQ光固化防龋涂料封闭,经恒温及冷热循环后置于0.1M/L的乳酸酸胶脱矿48h后,切片置于扫描电镜下观察。结果:有FQ防龋涂层的牙面在乳酸酸胶脱矿处理后,表面的封闭层仍然存在,对其下的牙体组织构成屏蔽保护层,故其牙体组织无明显脱矿表现。而无FQ防龋涂层的釉质脱矿较明显。结论:FQ光固化防龋涂料封闭法可起到预防牙釉质脱矿的作用。实验三:FQ光固化防龋涂料封闭层对牙表面与托槽间的黏结强度影响的研究。以20颗离体前磨牙为研究对象,制成牙片,经自凝塑料包埋,随机分为2组,每组10颗,对照组用临床常规手段黏结托槽,实验组先用FQ光固化防龋涂料封闭后再黏结托槽,经恒温水浴及冷热循环后进行抗剪黏结强度测试。结果:实验组和对照组的抗剪黏结强度比较差异无显著性。结论;FQ光固化防龋涂料封闭牙表面后不影响其与托槽间的黏结强度。实验四:FQ光固化防龋涂料封闭层的抗磨耗性研究。离体前磨牙20颗常规清洁后,随机分成2组,对照组无特殊处理;实验组用FQ光固化防龋涂料封闭,将两组样本置于牙刷磨耗试验机磨耗31000次后,进行扫描电镜观察。结果:FQ光固化防龋涂料的抗磨耗性满足临床工作要求。结论:用于预防正畸过程牙釉质表面脱矿的FQ光固化防龋涂料封闭层的抗磨耗性能满足临床应用要求。实验五:FQ光固化防龋涂料的生物安全性评价。按材料使用要求,制成FQ光固化防龋涂料圆片,按照GB/T16886.5-2003《医疗器械生物学评价》,进行体外细胞毒性试验。结果:FQ光固化防龋涂料无细胞毒性。结论:牙釉质表面脱矿FQ光固化防龋涂料封闭法具有安全可行性。综上所述,FQ光固化防龋涂料牙面封闭法可以作为一种预防正畸过程牙釉质表面脱矿的方法尝试性地应用于临床。这种方法在具有生物安全性、不影响牙面美观、不影响托槽黏结强度、具有良好的抗磨耗性能的应用前提条件下,能起到预防正畸过程牙釉质表面脱矿的作用。更多还原

【Abstract】 Fixed orthodontic treatment has become the most effective and widely used method in the treatment of malocclusion. However, oral environment has been changed, and the difficulty of brushing teeth was increasing after bonding the fixed appliance. Meanwhile,the reasons that the acid act on the tooth surface during the treatment, and patients pay less attention to oral hygiene leading to the high incidence of the enamel demineralization during the bonding process in orthodontic treatment. Demineralization leading to white spot lesions or cavities, which have a great influence on the patient’s dental health, appearance and their satisfaction. Therefore, how to prevent enamel demineralization during bonding process in orthodontic treatment becomes a great issue for orthodontist.FQ light-cured fluoride varnishes for preventing dental caries is a kind of homemade light-cured methacrylate resin by School of Stomatology, Fourth Military Medical University which possesses the advantages, such as good fluidity before curing, availability of thin coating, colorless after curing and having no significant effect on the appearance of tooth surface. In this study, we sealed the isolated teeth surface bonding to brackets in vitro by FQ light-cured fluoride varnishes for preventing dental caries. Dental aesthetics, anti-demineralization performance, and the adhesive strength of orthodontic brackets and the coating thickness and abrasion resistance and many other indicators were measured. It is assumed that the applicable and feasible way to prevent surface demineralization by FQ light-cured fluoride varnishes for preventing dental caries.Experiment 1: The observation of in vitro teeth with FQ light-cured fluoride varnishes for preventing dental caries and thickness measurement. After cleaning the in vitro teeth, surface morphology were observed before and after coating was observed under natural light, and comparative analysis on surface appearance and morphology were made after applying FQ light-cured fluoride varnishes for preventing dental caries. The thickness measurement of layer was taken after the scanning of in vitro teeth and analysis by software. Conclusion: colorless and transparent coating layer into the hidden layer on the surface of the teeth had no effect on morphological appearance, and thin layer can evenly distributed in the tooth surface.Experiment 2: Study on FQ sealing method to prevent enamel demineralization. The six premolars in vitro were randomly divided into control and experimental group. Experimental group was placed in 0.1M / L lactic acid gel demineralization before sealing by FQ for 48 hours under hot and cold cycles of constant temperature, and slices were scanned by electron microscopy. Results: The surface sealed layer which protect the dentin remains exist after applying FQ in lactic acid demineralization procedure.On contrary, control group without applying FQ has phenomenon of enamel demineralization.Experiment 3: Study on shear bond strength of enamel surface by applying FQ. To 20 in vitro premolars which were randomly divided into 2 groups (each group 10) were made into slices, and then embedded by self-curing resin. Control group was bonding with conventional clinical means; the experimental group was bonding before sealing by FQ, and shear bond strength of slices were utilized under hot and cold cycles of constant temperature. Results: The experimental group and control group have no significant differences in shear bond strength.Experiment 4: Study on wear resistance of enamel by applying FQ. Twenty premolars were randomly divided into 2 groups after regular cleaning. The experimental group was applied by FQ. The groups were placed in brush wear testing machine for 31000 times, and then scanned by electron microscope. Results: The anti-abrasion characteristic of FQ can meet the clinical requirements.Experiment 5: The evaluation of biological safety of FQ. Materials were made into light-cured round pieces by the requirements, in accordance with the GB/T16886.5-2003 "Biological Evaluation of Medical Devices": The in vitro cytotoxicity test was performed. Results: FQ paint curing dental has no cytotoxicity.In summary, FQ is a new aesthetic dental sealing material, and it possesses the advantage such as convenience for clinical work and no need for cooperation of patient. It can fully meet the clinical need of orthodontic work.更多还原