壮族人群恒前牙根管弯曲度测定

目的了解壮族人群恒前牙的根管弯曲情况。方法收集新鲜拔除的壮族人群恒前牙245颗,采用间接影像学手段观察其根管类型和弯曲形状,在Schneider法和Sch覿fer法的基础上,结合电子测量尺软件测量分析218颗Ⅰ型根管牙齿的弯曲度、弯曲半径和弯曲长度。结果壮族人群恒前牙以Ⅰ型根管为主,有13颗下颌中切牙和12颗下颌侧切牙为Ⅱ、Ⅲ、Ⅳ型根管。上颌中切牙、侧切牙、尖牙以及下颌中切牙、侧切牙、尖牙Ⅰ型根管近远中向弯曲发生率分别为40%、80%、77%、65%、66%、73%,唇舌（腭）向弯曲发生率分别为62%、69%、70%、62%、41%、61%。弯曲部位多在根尖1/3,多为中度弯曲;上颌尖牙在近远中向上的根管弯曲度最大,下颌尖牙在唇舌（腭）向上的根管弯曲度最大;上颌侧切牙在近远中和唇舌（腭）2个方向上的根管弯曲半径及弯曲长度均较小。结论壮族人群恒前牙根管弯曲情况较复杂,其下颌切牙Ⅱ、Ⅲ、Ⅳ型根管发生率较高。     

400颗上颌前牙根管弯曲情况的研究

目的了解上颌前牙根管弯曲情况。方法采用间接数字化X线成像技术拍摄400颗上颌前牙的近远中向和颊舌向X线影像,分析根管的弯曲情况。结果上颌前牙根管以Ⅰ型为主。上颌中切牙、侧切牙和尖牙只出现近远中向弯曲的比例为11.17%、16.19%、21.43%,只出现唇舌向弯曲的比例为39.59%、40.00%、29.59%,近远中向和唇舌向都存在弯曲的比例为4.60%、35.24%、24.49%。大约50%左右的上颌前牙根管存在中度弯曲;与上颌切牙相比, 上颌尖牙的弯曲度略大而弯曲半径略小。结论上颌前牙根管弯曲情况较复杂,其中以上颌尖牙为甚。充分了解根管的分型、弯曲度和弯曲半径是完善上颌前牙根管治疗的需要。     

回族和蒙古族成人前牙牙根弯曲情况比较研究

目的了解回族和蒙古族成人前牙根管弯曲情况。方法采用间接影像学手段,运用改良的Schneider测量方法,利用电子测量尺进行测量、分析两民族的根管弯曲情况。结果回族和蒙古族前牙根管多为Ⅰ型根管,且弯曲多发生在靠近根尖1／3处,回族下颌侧切牙、尖牙根管唇（颊）舌向弯曲发生率分别为（54．55％、68．42％）,与汉族接近,但明显高于蒙古族（17．65％、23．53％）,其间的差异具有统计学意（P〈0．05）;回族下颌中切牙近远中向的弯曲度明显大于汉族和蒙古族（P〈0．05）。回族上颌侧切牙及尖牙根管在唇舌方向的弯曲长度与汉族接近,均小于蒙古族（P〈0．05）,回族下颌中切牙根管在唇舌方向的弯曲长度与汉族接近,但大于蒙古族（P〈0．05）。S形根管在两民族前牙的发生比率相对较小。结论回族和蒙古族前牙根管弯曲情况与汉族一样较为复杂,不同种族的前牙根管弯曲情况确有差别。     

运用锥束CT对恒前牙根管变异的分析

目的采用锥束CT扫描所得图像数据,统计和分析前牙根管的变异。方法收集600例患者7200颗前牙图像数据,运用NNT软件,在冠状面、矢状面和横断面进行观察,统计和分析根管的数目、形态变异,根管类型,牙根数及两侧根管变异的对称性。结果 1根管数目：上颌前牙均为单根管,未见到根管变异;下颌前牙中330颗牙出现变异根管,为9.16%;2根管类型：上颌前牙均为Ⅰ型,下颌前牙Ⅰ型90.84%,Ⅱ型0.83%,Ⅲ型6.67%,Ⅳ型1.33%,Ⅴ型0.33%;3根管变异的对称性：上颌前牙不存在变异根管对称;下颌前牙两侧变异根管对称率：中切牙69.2%;侧切牙86.1%;尖牙66.7%;4牙根数：前牙除2例下颌尖牙为双根外,余均为单根。结论上颌前牙未见根管和牙根的变异;下颌前牙根管形态较复杂,根管变异率为9.16%,CBCT可准确发现根管变异。     

上颌乳前牙根管形态及根部牙本质力学性能的测定

目的 测量上颌乳前牙根管锥度、直径及根部牙本质的弹性模量和硬度,为用于上颌乳前牙的可吸收根管桩的制作提供参考。方法 选择全身麻醉下进行上颌乳前牙根管治疗的患儿,采用硅橡胶制取上颌乳前牙根管印模,扫描印模后测量根管的锥度和直径。收集10颗离体上颌乳前牙,测量根部牙本质的弹性模量和硬度。结果 本研究共收集了74颗上颌乳前牙的根管模型,其中乳中切牙28颗,乳侧切牙35颗,乳尖牙11颗。乳中切牙、乳侧切牙、乳尖牙的平均锥度依次为0.106、0.185、0.098,釉牙骨质界下方5 mm处平均直径依次为1.267、0.860、1.429 mm。10颗离体上颌乳前牙根部的牙本质弹性模量范围为19.919~25.017 GPa,硬度范围为0.867~1.082 GPa。结论 制作乳牙根管桩时,乳中切牙及乳尖牙根管桩建议取锥度为0.1,尖端直径为1.2、1.4 mm;乳侧切牙根管桩建议取锥度为0.2,尖端直径为0.8 mm;桩的弹性模量范围为20~25 GPa,硬度范围为0.87~1.08 GPa较为适宜。     

487颗下颌前牙根管的弯曲情况研究

目的:了解下颌前牙根管弯曲情况。方法:采用间接数字化X线成像技术拍摄487颗下颌前牙的近远中 向和颊舌向X线影像,分析根管的弯曲情况。结果:下颌前牙根管以Ⅰ型为主。26.22%的下颌切牙和31.45%的 下颌尖牙出现近远中向弯曲,7.01%的下颌切牙和18.87%的下颌尖牙出现颊舌向弯曲。下颌切牙Ⅰ型弯曲根管 颊舌向弯曲度(M=15.8°)最大;其弯曲半径(M=4.7mm)和弯曲长度(M=2.6mm)最小。结论:下颌前牙根管的 弯曲情况较复杂,以下颌切牙为甚。     

上颌前磨牙根管变异及其与上颌窦关系的锥形束CT研究

目的:利用锥形束CT研究上颌前磨牙牙根及根管系统解剖形态,为临床提供影像学依据。方法:选取720例成人患者（18~67岁）的锥形束CT扫描图像,按年龄分为5组：18~28岁、29~38岁、39~48岁、49~58岁及>58岁组,分析上颌前磨牙牙根及根管数、根管类型、两根管口间距离、根管弯曲度、根尖到上颌窦底距离、左右同名牙的对称性等及与年龄的关系。采用SPSS21.0软件包对数据进行统计学处理。结果:上颌第一前磨牙多为双根管（89.72%）,根管类型以Ⅳ型最常见（57.78%）。上颌第二前磨牙单根管发生率（53.06%）略高于双根管（46.94%）,根管类型以I型（53.06%）为主。左右同名牙牙根及根管数目多为对称分布。上颌前磨牙单根、双根管检出率随年龄变化而变化,两根管口间距离与根管类型关系密切。上颌第一、第二前磨牙颊舌向弯曲的根管检出率分别为32.53%和21.50%,存在S形复杂弯曲根管。16.69%的上颌第二前磨牙与上颌窦为关系密切型（d≤0.05 mm）。结论:上颌前磨牙牙根及根管解剖结构复杂,左右同名牙呈对称性。根管形态、结构和类型存在增龄性变化,根管弯曲情况复杂,牙根与上颌窦关系密切。     

离体上颌第二前磨牙根管颊舌向弯曲的发生情况

目的：确定人上颌第二前磨牙的颊舌向根管弯曲程度和情况。方法：收集213个离体的上颌第二前磨牙，拍近远中向的X线片，用Photoshop5．0软件分析根管，Weine氏法测量根管的弯曲度，测量角度大于18度时，则认为根管有明显的弯曲，根管的构型采用Vertucci分类法。结果：单根单根管上颌第二前磨牙的根管弯曲仅有2个，单根双根管牙齿的根管明显弯曲有6个，在28个双根牙中有明显根管弯曲的6个，根管弯曲的牙齿总发生率为6．6％(14/213)。根管弯曲的发生部位多为根尖1/3或附近。结论：上颌第二前磨牙颊舌向根管弯曲的发生率较低。     

激光与镍钛器械联合应用于根管治疗术一次法的临床效果

目的：观察脉冲Nd：YAG激光与镍钛机动器械联合应用于上颌前牙慢性根尖周炎根管治疗术一次法的临床效果。方法：对92例192个慢性尖周炎的上颌前牙随机分为3组，激光组61个牙，采取不锈钢K型锉预备，脉冲Nd：YAG激光消毒根管；镍钛器械组64个牙，采用镍钛机动器械Hero642系统预备根管；联合组67个牙，采用镍钛机动器械Hero642系统预备、脉冲Nd：YAG激光消毒根管。3组均采用根管治疗术一次法治疗，术后1周对3组根管充填后的疼痛反应进行评价，术后1年评价其疗效。结果：3组牙术后疼痛反应有显著性差别，激光与镍钛机动器械联合应用术后疼痛反应较轻（P〈0．05），1年疗效则无明显差别（P〉0．05）。结论：脉冲Nd：YAG激光与镍钛机动器械联合应用于慢性根尖周炎上前牙根管治疗术一次法，可减轻术后疼痛反应。     

上颌恒磨牙近中颊根根管弯曲情况的离体研究

目的 分析上颌恒磨牙近中颊根根管分型、弯曲发生情况、弯曲位置、弯曲方向及弯曲程度。方法 收集上颌第一、第二恒磨牙60颗，探查近中颊根管，并于根管内插入006#～015#扩大针，拍摄颊舌向(临床)和近远中向(邻面)X-线片。用Photoshop-6．0软件分析根管弯曲位置、弯曲方向和弯曲角度。结果 ①上颌第一恒磨牙近中颊根MB1根管的发现并探通率为90．6％；MB2根管的发现并探通率为71．8％，近中颊根以2—2型为主(48．27％)；上颌第二恒磨牙近中颊根MB1根管的发现并探通率为89．3％；MB2根管的发现并探通率为60．7％，近中颊根以2—1型为主(48％)。②大多数MB1与MB2根管在两个观察方向均有不同程度的弯曲。第一弯曲多发生于根中1／3及其冠方，临床片所示近颊根管多向远中弯曲，邻面片观察到的根管多向腭侧弯曲。在颊舌向发生的弯曲中，2—1型的MB2根管较MB1根管有更大的弯曲度；而2—2型的MB1与MB2根管弯曲度无显著性差异；2—1型的MB2根管弯曲的发生率与弯曲度均高于2—2型的MB1根管。在近远中向发生的弯曲中，2—1型的MB1根管弯曲度高于2—2型的MB1根管。③第二弯曲多发生于根尖1／3(部分发生于根中1／3)，弯曲度与第一弯曲度无显著性差异。结论 上颌第一、第二恒磨牙近中颊根管多有弯曲，充分了解根管的走向和弯曲度是完善根管治疗的必需。     

人上前牙根管治疗难度评估的实验研究

目的:利用X线放射影像学方法,评估人离体上前牙根管治疗的难度。方法:对80颗中国成人离体上前牙使用放射影像学等方法,获取解剖评估资料(共3组:正位片、侧位片、最大角度位片);采用根管治疗难度系数评估标准,进行根管治疗难度评估;采用多样本比较的秩和检验进行统计学分析。结果:①牙位2、3根管治疗的难度大于1,P<0.05,差异有统计学意义;2与3两者间差异无统计学意义,P>0.05。②1在3种不同投照片上难度总评的差异有统计学意义(P<0.05),最大角度位片>正位片>侧位片;2和3均无统计学意义(P>0.05)。③以正位片为考察对象,危险因素影响效力总体间差异有统计学意义的牙位是1(P<0.05)和2(P<0.01),弯曲度导致的难度>钙化度>牙长度;3无统计学意义(P>0.05)。结论:正位片能够正确反映上颌前牙各牙位的难度并作为评估依据。在上颌前牙中,1是难度总评最小的牙,2是弯曲度最大的牙。弯曲度是对1和2根管治疗产生最大难度效力的危险因素,而在3,3个危险因素均起同等的重要作用。     

常用根管消毒药物对犬牙根管内优势致病菌消毒作用研究

目的:对比研究碘仿糊剂、FC、Vitapex和氢氧化钙糊剂4种根管消毒药物对犬牙根管内根尖周病优势致病菌的抗菌活性。方法:健康成年杂种犬4只,随机选取单根管前牙,建立犬牙根尖周病模型。取根管预备前后根管内细菌进行培养和计数,将碘仿糊剂、FC、Vitapex、氢氧化钙糊剂分别封入4组根管内,对照组封无菌纸捻,7 d后再取样进行细菌培养和计数,对细菌计数结果进行统计学分析。结果:①根管预备后的各种细菌数量均较根管预备前明显减少,差异有统计学意义(P<0.05);②封药后根管内细菌数量大部分为0,但4种消毒药物抗菌活性比较无显著统计学意义(P>0.05)。结论:完善的根管预备能有效去除大部分根管内优势致病菌,4种消毒药物对犬牙根管内的优势致病菌均有抗菌作用。     

Accessory roots and root canals in human anterior teeth: a review and clinical considerations

Anterior teeth may have aberrant anatomical variations in the number of roots and root canals. A review of the literature was conducted using appropriate key words in major endodontic journals to identify the available reported cases as well as experimental and clinical investigations on accessory roots and root canals in anterior teeth. After retrieving the full text of related articles, cross‐citations were identified, and the pooled data were then discussed. Results revealed a higher prevalence in accessory root/root canal variations in mandibular anterior teeth than in maxillary counterparts. However, maxillary incisor teeth revealed the highest tendency for accessory root/root canal aberrations caused by anomalies such as dens invaginatus and palato‐gingival groove. Primary anterior teeth may also exhibit external and internal anatomical variations in the root, especially maxillary canines. Therefore, dental practitioners should thoroughly assess all teeth scheduled for root canal treatment to prevent the undesirable consequences caused by inadequate debridement of accessory configurations of the root canal system.     

Root resorption associated with ectopically erupting maxillary permanent canines: a computed tomography study

The aims of this retrospective computed tomography (CT) study were to determine the occurrence of severe root resorption involving the pulpal canal of adjacent permanent teeth associated with ectopically erupting canines, and to verify the existence of related factors. The sample consisted of 255 consecutive patients (159 females and 96 males, mean age 18.4 and 16.8 years, respectively). Three hundred and thirty-four ectopic maxillary canines and adjacent teeth were analysed using CT images. Statistical significance was evaluated with chi-square and Fisher's exact tests. The results showed that severe root resorption of adjacent permanent teeth occurred in 17.7 per cent of ectopic canines and was equally common in females and males. Severe root resorption affected 12.6 per cent of the lateral incisors, 4.8 per cent of the first premolars, and 2.1 per cent of the central incisors. No relationship was found between the type or side of ectopic eruption, inclination of the longitudinal axis of the ectopic canine and the occurrence of severe root resorption. A significant relationship was found between a bucco-lingual position of the ectopic canine and root resorption (P < 0.05). Root resorption mainly occurred in the apical third (57.6 per cent) and apical and middle thirds (27.1 per cent). A significant relationship existed between the occurrence of root resorption and complete loss of space for the erupting canine (P < 0.05). No association was found between alignment of the upper permanent incisor and root resorption. A widened dental follicle occurred in 15 per cent of ectopic canines but did not cause root resorption of the adjacent permanent teeth. Since root resorption is asymptomatic, early detection by radiographic examination is essential for correct diagnosis and treatment.     

Evaluation of the root canal configurations of the mandibular and maxillary permanent teeth by gender in the Turkish population

A key objective of successful nonsurgical endodontic treatment is obturation of the root canal systems. One factor in achieving this goal is the knowledge of possible root canal morphologies. Root canal morphology may exhibit variation as a result of many factors, including ethnic origin. In this study, 1400 male and 1400 female extracted mandibular and maxillary permanent teeth were evaluated for patterns in root canal morphology. The mandibular and maxillary teeth were divided into seven groups of tooth type (e.g. centrals, laterals, canines, first premolars, second premolars, first molars, and second molars), subdivided into gender, and classified by root canal morphologies. Vertucci's classification was taken as a reference during the evaluation. Although a majority of the specimens corresponded to this classification scheme, the analysis of this large data set revealed 14 additional root canal morphologies.     

Double-rooted primary canines: A report of three cases

This article reports three rare cases of birooted primary canines. In one of the three cases reported, the double-rooted primary canine was unilateral, which is a unique condition in the dental literature. One of the birooted primary canines was extracted for examination. Root canal morphology was examined using the clearing technique and three root canals were detected. The detection of birooted teeth requires a fastidious radiographic evaluation. Moreover, it should be kept in mind during endodontic therapy that the number of root canals might exceed the number of roots for these teeth.     

前牙髓腔完全钙化的临床研究

目的：探讨完全钙化根管行根管治疗术的可行性。方法：对26例完全钙化前牙根管行根管治疗术，进行术前术后X线片对比研究。结果：24例顺利完成根管治疗术，2例因根管口完全钙化行根尖手术。结论：完全钙化的前牙根管X线片上显示为根管闭锁，临床上可通过寻找根管口，逐步扩大根管完成根管治疗术，以避免根尖手术或牙拔除术。