【作者】 刘玉红；

【导师】 王忠义； 何惠明；

【作者基本信息】 第四军医大学 ， 口腔临床医学， 2008， 博士

【摘要】 口腔内残根、残冠的保存修复主要依赖于桩-核-冠修复技术,桩在其中起到至关重要的作用。在过去的临床工作中,多采用金属桩进行修复,由于金属桩的弹性模量远远大于牙本质的弹性模量,常常造成根折现象的发生。目前,弹性模量较为接近牙本质的纤维增强树脂基复合材料桩开始进入临床,有效地避免了牙折现象的发生,但此类桩都属于预成桩,无法实现根管桩的个性化制作,而且也无法满足牙冠改向的灵活性要求。所以,研究一种具有可塑性的、能够实现个性化制作的纤维增强树脂基复合材料桩显得尤为重要。在国外,仅有芬兰的Stick Tech公司研制出了一种符合上述要求的纤维桩,其商品名为Ever Stick;但在国内尚无该类桩的研究报道,因此,本研究尝试利用光固化技术、纤维增强技术和互穿聚合物网络技术研制出一种可塑性纤维增强树脂基复合材料桩,并对其机械性能、生物安全性和临床相关粘接性能进行初步评价,为该桩进一步完善并进入临床应用奠定实验基础。本研究采用如下技术路线:首先,制备互穿聚合物网络结构的树脂基体;其次,初步探求不同纤维含量对纤维增强树脂基复合材料力学性能的影响;然后,确定最佳光引发体系;再选择最佳光照时间,以求获得最佳力学性能;最后,合成光固化型可塑性纤维增强树脂基复合材料桩,并对材料的生物安全性及临床粘接性能进行了初步评价。研究内容和方法:1.互穿聚合物网络结构树脂基体的制备。选择口腔树脂材料中常用的Bis-GMA和MMA作为基体,通过不同比例配伍,在一定的工艺条件下形成共聚物,通过力学性能和各种相关的高分子结构检测手段,筛选出能够形成较为理想的互穿聚合物网络结构的树脂基体配比方案。2.不同纤维含量对纤维增强树脂基复合材料力学性能的影响及含量配方的确定。采用不同含量的玻璃纤维来增强树脂基体,通过合成材料的力学性能测试,探索其影响规律,确定其含量配方。3.不同光引发体系对纤维增强树脂基复合材料固化性能的影响及配方的确定。改变光引发体系中各组成成分的含量,通过力学性能和树脂单体转化率的测定,确定其配方。4.光照时间对纤维增强树脂基复合材料力学性能的影响。采用不同光照时间对纤维增强树脂基复合材料进行固化,通过力学性能的检测,确定最佳的光照时间。5.合成光固化型可塑性纤维增强树脂基复合材料桩。通过对其力学性能的评价,获得最佳配方和工艺,自行合成光固化型可塑性纤维增强树脂基复合材料桩。6.自行研制合成桩的生物安全性的评价。按照国家相关标准,采用实验手段,分别对自行研制合成的桩进行体外细胞毒性试验、溶血试验、粘膜刺激试验和短期全身毒性试验。7.自行研制合成桩与根管牙本质间粘接性能的研究。以Ever Stick桩为对照,利用三种不同牙本质粘接剂将自制桩和Ever Stick桩分别与根管牙本质进行粘接,采用微推出试验检测并比较粘接性能,并对断口形貌进行显微观察。8.自行研制合成桩与树脂核材料间粘接性能的研究。以Ever Stick桩为对照,利用三种不同树脂核材料将自制桩和Ever Stick桩分别进行堆塑、包埋,采用微推出试验检测并比较粘接性能,并对断口形貌进行显微观察。研究结果:1.Bis-GMA和MMA按不同比例共混,采用分步合成法形成互穿聚合物网络结构,并且在MMA含量为20%时,其结构和性能最佳。2.在已形成互穿聚合物网络结构的树脂基体中添加73.8wt%左右的玻璃纤维可以达到最理想的增强效果。3.CQ/EDB光引发体系的最佳配比为:CQ占0.5wt%,EDB占1.0wt%。4.综合考虑材料固化后的力学性能和临床操作的效率,合成材料的最佳光照时间为60S。5.自行合成并获得了可塑性纤维复合材料桩,其可塑性和可操作性较强,弯曲强度可达647.73Mpa,弹性模量达33.8GP,更接近于牙本质。6.自行研制合成桩无明显细胞毒性;溶血率仅为1.76%,不会引起急性溶血反应;对口腔粘膜无刺激性;不会引起短期全身毒性反应。7.在与牙本质和树脂核材料的粘接效果上,自行研制合成的FRC桩与国外同类产品——Ever Stick纤维桩之间无显著性差异。GC Fuji PLUS、Panavia F和3M ESPE RelyXtm Unicem的牙本质粘接剂在桩与牙本质的粘接中,也无显著性差异。8.Clearfil APX树脂核材料与自行研制合成桩之间的粘接强度显著高于3M ESPE Filtektm Z250和Dentsply Definite Core的核材料。结论:同时应用光固化技术、纤维增强技术和互穿聚合物网络技术可以制得力学性能较好的根管桩,该桩钉具有可塑性,能够实现个性化制作,同时可以满足牙冠自由改向的灵活性操作要求。与国外同类产品——Ever Stick纤维桩相比,其粘接性能无显著性差异。本研究中的工艺和配方尚属于实验室阶段,若经进一步完善和改进,则此类桩有望能够更快地进入临床工作中。更多还原

【Abstract】 The post-core-crown system is mainly applied in restoration of the residual crown or root, in which the post plays an important role. In the past, the metal post was mostly applied in this procedure. However, it caused the root fracture at every turn, for the elastic module of the metal post is far larger than that of dentin. At present, the post of fibre reinforced composite (FRC) is applied in clinical procedure gradually, which can prevent the root from fracturing, for its elastic module is approximate to that of dentin. But the FRC post is prefabricated, it can not be shaped individually to fit the different figure of root canal, and can not meet the clinical needs of modifying crown direction flexibly. So, it is necessary to develop a kind of FRC post which possesses plasticity and can be shaped individually. At abroad,only a kind of fibre post named Everstick is developed by StickTeck company in Finland,which can meet the above needs.However,there is no studies on this kind of fibre post at home.In this research, a kind of plastic FRC post was developed with the light cure technology, fibre reinforced technology and interpenetrating polymer network (IPN) technology, and was evalued elementarily on some properties including mechanics performances, biological safety and adhesive abilities. This research laid an experimental foundation to introduce this kind of post to the clinical applications.In this research, the Strategy and Procedure is studied from part to entirety and from process to properties. Firstly, we discussed the influence of different compose on the properties of composites, according to the basal mechanical properties of material matrix. At the same time, the synthesis process and formula is groped. Then the biology security of material was primary evaluated. At last, the adhesion which is closed contacted with clinic application was studied.The content and method are as follows:1. Preparation and formula of interpenetrating polymer network (IPN) of polymer were studied. The Bis-GMA and PMMA which is common material in oral cavity resin were used as matrix. Bis-GMA and PMMA were mixed with different ratio, then react in certain condition to form IPN polymer. The best ratio to form IPN polymer were confirmed according to the mechanical properties and Tg.2. The influence of glass fiber content on mechanical properties of fiber reinforced composites (FRC) was studied. Then the effect rules on mechanical properties were discussed.3. The influence of light initiation system on curing properties of fiber reinforced composite was studied. According to the mechanical properties and conversion of resin, the components content of light initiation system were confirmed. 4. The influence of the light time on mechanical properties of fiber reinforced composites was studied. According to the mechanical properties, the light time of curing resin composites were confirmed.5. Dental plastical IPN posts polymer composites were synthesized, according to the above formula and process. The mechanical properties of IPN posts were studied.6. The biological safety of the post made by self-fabricated dental plastical IPN posts polymer composites was evalued by MTT test, hemolysis test in vitro, oral mucous membrane irritation test, acute general toxicity test.7. The micro push-out test was applied to evalue the adhesive abilities between the post made by self-fabricated dental plastical IPN posts polymer composites and dentin with three kinds dentin adhesive agent, which was compared with that of EverStick, and microscopy was applied to observe the structure of the fracture section.8. The micro push-out test was applied to evalue the adhesive abilities betwwen the post made by self-fabricated dental plastical IPN posts polymer composites and three kinds of resin core materials, which was compared with that of EverStick, and microscopy was applied to observe the structure of the fracture section.The results are as follows:1. In certain condition, Bis-GMA and MMA can form the better IPN structure. The structure and properties is best when the MMA content is 20%.2. When the glass fiber content is about 73.8%, the properties of IPN composites reached best.3. The best ratios of CQ and EDB in light initiation system are 0.5 wt% and 1.0 wt% respectively.4. According to the mechanical properties and clinic manipulation, the best light curing time is 60S.5. Dental IPN posts polymer composites are plastical and easy to clinic manipulation. In addition, the bend strength is 647.05MPa, and the bend modulus is 33.03GPa, which closed to the mechanical properties of dental essence.6. The post made by self-fabricated dental plastical IPN posts polymer composites was avirulent to cells, was considered to bring no hemolysis phenomena and be no influences on function of cruor, for the hemolytic rates of samples is 1.76%, have no mucous membrane irritations, could not induce acute general toxicities.7. There was no significant diference on adhesive effects to dentin between the post made by self-fabricated dental plastical IPN posts polymer composites and EverStick. There was no significant diference on adhesive effects among utilizing GC Fuji PLUS, Panavia F and 3M ESPE RelyXtm Unicem.8. Clearfil APX could adhere to the post made by self-fabricated dental plastical IPN posts polymer composites better than 3M ESPE Filtektm Z250 or Dentsply Definite Core.Conclusions: The new pattern FRC post can be fabricated with the light cure technology, fibre reinforced technology and interpenetrating polymer network (IPN) technology. It possesses good mechanics performances and plasticity, and can be shaped individually and meet the clinical needs of modifying crown direction flexibly. There is no significant diference between self-fabricated FRC post and EverStick. In this research, the technics and components buildup is at the experimental level, and need more improved.更多还原