目的针对临床钙化阻塞根管预备中是否采用EDTA凝胶辅助C型先锋锉和手用ProTaper镍钛锉进行根管预备的临床效果比较,以其提高口腔根管治疗质量。方法制定严格筛选标准,选取根管细小钙化患牙50颗,钙化根管136个,随机分为两组,实验组采用EDTA凝胶辅助C型先锋锉和手用ProTaper镍钛锉预备根管70个;对照组不使用EDTA凝胶,只用C型先锋锉加手用ProTaper镍钛锉预备根管66个,根据X线片和临床指标等检查比较两组根管预备效果。结果实验组70个钙化根管有61个根管扩通,达到根管预备要求,成功率87.14%;对照组66个钙化根管有34个根管扩通,成功率51.52%,对比两者之间有显著差异。结论在临床钙化阻塞根管的机械预备中应用EDTA凝胶辅助,可极大提高钙化阻塞根管的疏通率,提高口腔根管治疗质量,有效保留患牙。

Objective To compare clinical effect of root canal preparation by ProTaper nickel titanium and EDTA gel preparation, to improve the quality of root canal therapy. Methods The strict screening criteria, selection of fine root canal calcification 50 teeth, calcified root canal 136, were randomly divided into two groups, the experimental group with EDTA gel assisted C pioneer file and hand ProTaper nickel titanium file in root canal preparation70;control group without the use of EDTA gel, only C pioneer file hand ProTaper nickel titanium file in root canal preparation 66, according to the X-ray and clinical examination were compared between the two groups of root canal preparation effect. Results 70 calcified root canals of 61 root canal expansion, to prepare for the root canal, the success rate was 87.14%;the control group 66 calcified root canals of 34 root canal expansion, the success rate was 51.52%, there was a significant difference between the two comparison. Conclusion The applica

目的探讨Raypex 5根管测量仪在根管治疗中根管工作长度测量的准确性。方法 200例进行根管治疗的患者,共520根根管,随机分为两组,实验组用Reypex 5根管测量仪测量根管工作长度,对照组用X线测量法测量,常规根管预备并充填,拍摄X线片比较充填质量。结果实验组适充率91.92%,高于对照组79.62%,差异有统计学意义(P0.01)。结论 Raypex 5根管测量仪能够准确、方便、有效的测量根管工作长度,值得临床推荐使用。

Objective To explore the accuracy of Raypex5 electronic apex locator in determining root canal working length in the root canal therapy. Methods Divided 200 patients who treated with root canal therapy, all 520 roots, into two groups, the experiment group was measured the root canal working length with Raypex5 electronic apex locator, while X-ray method was used in the control group. All canals were prepared and filled. Results The accuracy rate was 91.92%in the experiment group, while 79.62%in the control group, the difference was statistically significant. Conclusion Raypex5 electronic apex locator is accurate, convenience, effective in determination of root canal length, so it is worthy of clinical promotion.

探讨了第一类切比雪夫型基本方程Tn(x)=Tm(x)的重根现象,得到Tn(x)=Tm(x)有重根的充要条件、其全体复根均为单根的充要条件和计算重根个数的公式这三个定理以及一些有用的推论.

This paper studies the multiple root phenomenon of the first kind Tschebyscheff basic equa-tion Tn(x)=Tm(x) and gets three theorems :the necessary and sufficient condition of having multiple root of Tn(x)=Tm(x) ,the necessary and sufficient condition of only having single root of Tn(x)=Tm(x) as well as the expression on counting the number of its multiple root. Besides, it also gets some other useful conclusions.

目的探讨氢氧化钙碘仿糊剂用于有瘘型根尖周炎根管消毒的疗效。方法选择有瘘型根尖周炎患牙120颗随机分为两组,治疗组选用氢氧化钙碘仿糊剂根管内封药,对照组选用甲醛甲酚联合碘仿根管内封药,对两组封药2周后患牙疗效以及根管治疗期间疼痛（EIP）发生率进行比较。结果治疗组总有效率为96.67%,对照组总有效率为83.33%,其差异有统计学意义（P〈0.01）;治疗组EIP发生率6.67%,对照组EIP发生率20%,其差异有统计学意义（P〈0.05）。结论氢氧化钙碘仿糊剂用于有瘘型根尖周炎能有效控制感染及预防根管治疗期间疼痛的发生。

Objective To investigate the curative effect of calcium hydroxide iodoform paste used for root canal disinfection fistula. Methods The choice of fistula periapical periodontitis in 120 teeth were randomly divided into two groups, the treatment group were treated with calcium hydroxide intracanal medicament, the control group used formocresol joint iodoform intracanal medica-ment, two groups of letter 2 weeks after dental treatment and endodontic interappointment pain (EIP) to compare the incidence of. Results The total effective rate of treatment group was 96.67%, control group, the total effective rate was 83.33%, the difference was statistically significant (P<0.01); the incidence of EIP was 6.67% in the treatment group, the control group the incidence of EIP was 20%, the difference was statistically significant (P<0.05). Conclusion Calcium hydroxide iodoform paste used for fistula periapical periodontitis can effectively control the infection and prevention of root canal t

目的：以不锈钢K锉作对照,评价机用单根锉WaveOne和机用ProTaper镍钛器械成形及清理重度弯曲根管的能力。方法收集新鲜拔除的离体牙,选取弯曲度为25°~45°的根管30个,随机分成W、P、K 3组,每组10个。 W组：使用WaveOne机用往复式镍钛合金锉冠向下法预备根管；P组：使用ProTaper机用镍钛锉冠向下法预备根管；K组：使用不锈钢K锉逐步后退法预备根管。分别于预备前、后进行锥体束CT ( cone beam computed tomography,CBCT)扫描,比较在距根尖1.5mm、2.5mm、4.5mm、5.5mm处各组根管偏移值差异。将30个根管剖开,通过扫描电子显微镜观察根管预备后根管内壁的碎屑和玷污层。结果在距根尖1.5mm、2.5mm、4.5mm、5.5mm处四层水平上,K组发生的偏移值均较大,与P组和W组相比差异有显著性(P0.05)。扫描电镜下,3组之间在各部分碎屑评分上两两比较差异有显著性(P0.05),而在根管冠1/3和根中1/3处评分差异有显著性(P0.05)。结论 WaveOne和ProTaper预备重度弯曲根管具有良好的成形能力,保持原有根管走向的能力优于不锈钢K锉；配合次氯酸钠冲洗,单根锉WaveOne对根管的清理效果最优。

Objective To evaluate the shaping ability and cleaning efficiency of rotary single-file WaveOne and rotary ProTaper in severely curved root canals by compared with stainless steel K-file. Method 30 root canals with curva-tures ranging from 25° to 45° were selected and randomly assigned to W,K,P three groups with 10 teeth in each. W group:Crown-down technique with single-file WaveOne was used in root canal preparation; P group:Crown-down technique with rotary ProTaper was used in root canal preparation;K group:modified step-back technique with stain-less steel K-file was used in root canal preparation. Cone beam computed tomography scans were performed respec-tively before and after the preparation to evaluate the offset value of root canal at 1. 5mm, 2. 5mm, 4. 5mm and 5. 5mm from the root apex. After preparation,the roots were split into two halves longitudinally and root canal walls were examined the distribution of debris and smear layer under scanning electron microscop