3种暂封材料在根管治疗中冠方微渗漏的体外效果观察

目的观察3种暂封材料在根管治疗中冠方微渗漏的体外效果。方法选取近期拔除的完整前磨牙45颗,备洞开髓建立直线通路,随机分为3组,分别用氧化锌丁香油水门汀、牙胶条、Caviton亲水性暂封材充满窝洞,经封闭处理后浸入2%亚甲蓝溶液,1周后取出纵剖牙齿,测量染料渗入深度。结果牙胶条染料渗漏最多,氧化锌丁香油水门汀其次,Caviton亲水性暂封材渗漏最少。3种暂封材料冠方微渗漏差异有统计学意义(P<0.05)。结论 Caviton亲水性暂封材封闭效果优于氧化锌丁香油水门汀和牙胶条。     

3 种根管充填材料体外封闭性能比较

一般认为严密的根管充填是根管治疗成功的关键步骤之一,而在决定传统的糊剂加牙胶尖根管充填严密性的诸多因素中,糊剂的根管封闭能力起着重要作用。本实验旨在通过比较3种根充糊剂的根管封闭能力,为临床选择使用根充糊剂提供一定的指导。1　材料和方法1. 1　实验材料国产根管充填剂(上海第二医科大学张江生物材料有限公司生产,批号: 031103),成分:粉剂含麝香草酚、氧化锌,液体含甲醛、煤酚、甘油。Cortisomol根管充填剂(法国产 ),成分:粉剂含强的松龙醋酸盐、多聚甲醛、氧化锌、红铅和赋形剂等,液体为丁香油。Apexit根管充填糊剂 (列支…     

3种根管充填材料冠方微渗漏的体外评价

目的:评价3种根管充填材料的根管冠向封闭能力,为临床采用不同的根充材料提供理论依据.方法:55颗离体单根前牙或前磨牙自釉牙骨质界截断,随机分成A、B、C 3个实验组(每组15颗牙)和D、E 2个对照组(每组5颗牙),A、B、C组分别采用Cortisomol糊剂加牙胶尖,AH-plus糊荆加牙胶尖及Resilon-Epiphany根管树脂充填材料行冷侧压充填根管,D组为阳性对照组,E组为阴性对照组.牙齿用2%甲基蓝溶液浸泡,沿牙长轴纵向剖开标本,双盲下用游标卡尺测量色素渗入根管的长度(精确至0.02mm).结果:A、B、C3个实验组染料渗入长度分别为(2.35±0.58)mm、(1.88±0.24)mm、(1.57±0.24)mm,阳性对照组的染料渗入根管全长,阴性对照组无染料渗入.A组与B、C组间染料渗入长度差异有显著性(P＜0.01),B组与C组间染料渗入长度有差异显著性(P＜0.05).结论:Resilon-Epiphany树脂根管充填材料冠方封闭性优于AH-plus糊剂与Cortisomol糊剂.     

根管充填后冠方渗漏的体外实验

冠方渗漏是根管治疗失败的主要原因之一，体外实验是评价冠方渗漏的常用方法，主要有：放射性核素渗漏实验、染料渗漏实验和微生物渗漏实验。本文就这些方法作一综述。     

桩道制备后根管冠方渗漏的体外实验

目的 本实验拟用染色实验，比较根管内牙胶余留全长、3、5、7mm两周后的冠方渗漏，为探讨桩道制备后根管充填的封闭性能做一参考：方法取86颗单根离体牙，按照牙胶余留量及暂时充填材料的不同分为8组，常规根管充填并桩道预备后，用次甲基蓝进行由冠方向根方的渗漏，2周后测量渗漏深度，统计结果并加以分析。结果各组均有渗漏，其中以牙胶封闭且根管内牙胶余留3mm组的渗漏距离最大．以氧化锌水门汀封闭且未去除根管内牙胶组的渗漏距离最小。但是8组的渗漏深度差异无统计学意义（P=0．1033）。结论桩道制备会增加根管充填的冠方渗漏，而氧化锌水门汀的封闭性能较牙胶强，但在两周时间内渗漏对根尖部封闭性能影响不大．     

不同根管充填材料的封闭性能比较

根管充填作为根管治疗的最后一步．其质量对于治疗整体效果有着至关重要的影响。而根管充填的质量除与根管预备、根管消毒的效果密不可分外，与根管充填材料的性质也有密切关系。     

GuttaFlow充填系统根管封闭性能初探

目的评价GuttaFlow常温流动牙胶充填系统的根管封闭性能。方法30颗单根管牙沿釉牙骨质界截冠,采用冠向下法,使用ProTaper机用镍钛系统预备根管。随机分为3组,每组10颗,分别以GuttaFlow充填系统、冷侧压充填法、连续波热塑牙胶充填术充填根管。采用葡萄糖定量法测定第2、7、14、21、28天从冠方向根方渗漏的葡萄糖量。结果从实验第21天起,GuttaFlow充填系统的葡萄糖渗漏量要明显低于冷侧压充填法(P<0.05),而与连续波热塑牙胶充填术相比没有统计学差异(P>0.05)。结论GuttaFlow充填系统在观测期内具有较好的根管封闭性能。     

暂时封固对根管治疗牙冠方微渗漏影响的体外研究

目的 评价不同暂封材料、暂封方式对根管治疗牙冠方微渗漏的影响,探讨根管治疗牙冠方微渗漏发生情况及与时间的关系.方法 收集离体牙,常规根管治疗后随机分组,2%亚甲基蓝染色,制作透明样本,体视显微镜下观察样本微渗漏情况,根据染料渗漏最大长度评分,收集数据并进行统计分析.结果 暂封1、4 周时,Cavit-G和Caviton微渗漏评分低于氧化锌丁香酚水门汀(ZOE);暂封2 周,Caviton微渗漏评分低于ZOE和Cavit-G.ZOE作为暂封材料,两种方式样本微渗漏评分比较差异无统计学意义(P > 0.05);暂封1 周时,Cavit-G和Caviton直接与间接暂封微渗漏评分差异无统计学意义(P > 0.05),暂封2周,Cavit-G和Caviton微渗漏评分差异无统计学意义(P > 0.05).随暂封时间的延长,3种材料的微渗漏差异有统计学意义(P < 0.05).结论 Caviton冠方暂封效果最好,其次为Cavit-G,ZOE最差;间接暂封明显加速Cavit-G和Caviton暂封样本冠方微渗漏;Caviton和 Cavit-G用于暂封的适宜时间为2周,ZOE为1周.     

五种髓腔暂封材料冠方微渗漏的体外评价

目的:评价CIMAVIT(碧兰)、Coltosol(康特)、CavitG(3M)、IRM(登士柏)和氧化锌丁香油酚粘固剂(ZOE,北京)等5种髓腔暂封材料的冠方微渗漏。方法:选取近期拔除的磨牙及前磨牙42个,排除龋齿、隐裂及牙合面过度磨耗牙。开髓并制作髓腔直线通路,洞缘1mm以外牙面封闭。随机分为5组,每组8个牙,分别用上述5种材料充填髓腔入口至充满。2个牙做对照,髓腔不充填。材料固化后,将试验牙浸入2%亚甲兰染料中,经过4℃和56℃各2min共40次温度循环及室温下16h浸泡,纵剖牙齿,观察染料沿洞壁与充填体间隙渗入的深度并分析各材料组间的差异。结果:5种材料的冠方渗漏有显著性差异(P<0.01)。CIMAVIT和Coltosol染料渗漏最少,IRM产生最多的微渗漏。结论:CIMAVIT和Coltosol可获得较理想的髓腔封闭效果。     

比较2种根管充填糊剂对根尖封闭性的作用

目的用染料渗透法测量根管微渗漏的程度,比较2种根管充填糊剂在根管充填后不同时间进行桩腔预备后对根尖部的封闭能力。方法选取90颗成人的上颌中切牙,逐步后退法预备根管,侧向加压技术充填根管,充填剂分别用Cortisomol糊剂（A组）和氧化锌丁香油糊剂（B组）,每组45颗上颌中切牙。根据根管充填后桩腔预备时间将A组上颌中切牙随机分为A1组、A2组和A3组,每组15颗,A1组为根管充填后即刻进行桩腔预备,A2组为根管充填后2周进行桩腔预备,A3组为根管充填后4周进行桩腔预备。根据根管充填后桩腔预备时问将B组上颌中切牙随机分为B1组、B2组和B3组,每组15颗,B1组为即刻进行桩腔预备,B2组为根管充填后2周进行桩腔预备,B3组为根管充填后4周进行桩腔预备。进行桩腔预备后用染料渗透法评价各组根尖渗透能力。结果Cortisomot组（A组）与氧化锌丁香油组（B组）在根管充填后相同时间进行桩腔预备后,根尖微渗漏的差异具有统计学意义（P〈0．01）。A组在根管充填后即刻、2周、4周时进行桩腔预备,其根尖微渗漏的差异具有统计学意义（P〈0．01）。B组在根管充填后即刻、2周、4周时进行桩腔预备,其根尖微渗漏的差异无统计学意义（P〉0．05）。结论Cortisomol根管充填糊剂的封闭作用效果比氧化锌丁香油糊剂好。     

三种桩封闭根管冠方能力的实验研究

目的 研究纤维桩与金属桩根管冠方封闭能力的差异.方法 45颗离体前牙根管充填后随机分成A、B、C组,每组15颗牙齿.分别用石英纤维桩(A组)、预成金属螺纹桩(B组)和铸造平滑桩(C组)进行修复.经30万次负荷加载后制成透明标本,显微镜下观察并测量每组标本冠方的微渗漏长度,对数据进行统计分析.结果 A组15颗牙只观察到2颗渗漏,螺纹桩组和铸造桩组30颗牙全部发生渗漏.平均渗漏长度:A组为(0.057±0.168)mm;B组为(2.136±0.678)mm;C组为(2.358±0.838)mm,方差分析结果表明3组之间差异有统计学意义,F=315.491,P<0.001.结论 纤维桩对根管冠方的封闭能力优于金属桩.     

Fracture Resistance of Endodontically Treated Teeth: Three Walls versus Four Walls of Remaining Coronal Tooth Structure

Purpose: The purpose of this study was to evaluate the fracture resistance of endodontically treated teeth between those with four walls and those with three walls of remaining coronal tooth structure and the effect of the site of the missing coronal wall.
Materials and Methods: Thirty-two endodontically treated second mandibular premolars were decoronated, leaving 3 mm above the cementoenamel junction (CEJ). A 0.5-mm-wide chamfer was prepared 1 mm above the CEJ. The teeth were randomly divided into four groups. Group 1 had four walls of coronal tooth structure, whereas groups 2, 3, and 4 had only three walls, missing the buccal, lingual, and mesial wall, respectively. The cast dowel and cores and crowns (Ni–Cr alloy) were cemented with zinc phosphate cement. A compressive load was applied 45° to the long axis, 2 mm below the buccal cusp, with an Instron machine until failure at a crosshead speed of 5 mm/min. Failure load (kg) and mode of failure were recorded. Data were analyzed with one-way ANOVA and Scheffé tests ( p < 0.05).
Results: Group 1 had the highest fracture resistance (1190.3 ± 110.5 kg), significantly different from the other groups ( p < 0.05) (group 2: 578.5 ± 197.4 kg; group 3: 786.6 ± 132.8 kg; group 4: 785.4 ± 289.9 kg). There were no significant differences among the test groups. The mode of failure in group 1 was a horizontal root fracture, whereas that of the other groups was either vertical or oblique fracture.
Conclusions: Teeth with four walls of remaining coronal dentine had significantly higher fracture resistance than teeth with only three walls. The site of the missing coronal wall did not affect the fracture resistance of endodontically treated teeth.     

A Practice-based Study on the Survival of Restored Endodontically Treated Teeth

IntroductionThis retrospective study evaluated the survival of endodontically treated teeth (ETTs) and investigated factors influencing restoration and tooth survival.MethodsData from 795 ETTs were recorded, and success (restoration still intact) and survival (restoration intact or failed/repaired/replaced and tooth still in situ) were analyzed using Kaplan-Meier statistics. A multivariate Cox regression analysis was performed to assess the variables influencing success and survival.ResultsAt the end of the observation period (mean observation time = 4.48 years), 45 teeth had been extracted (annual failure rate for survival = 1.9% at 9.6 years) and 114 restorations had received a restorative follow-up treatment (annual failure rate for success = 4.9% at 9.6 years).ConclusionsETTs showed acceptable survival and success in the long-term. Variables showing significant influence on survival were the number of teeth in the dentition and the presence of decay at the moment the patient entered the practice.     

Shrinkage Strains in the Dentin of Endodontically Treated Teeth with Water Loss

IntroductionDehydration has been considered as a potential contributor to vertical root fractures (VRFs) after root canal treatment (RCT). A loss of water could cause embrittlement of dentin and detrimental shrinkage strains. Senior patients have the highest risk of VRF. In this study, we characterized the spatial distribution in shrinkage of tooth roots with respect to donor age and prior RCT.MethodsSingle-rooted human teeth with and without prior RCT were collected from young (age <25 years) and old (age >60 years) adults. Transverse slices were sectioned from the apical, middle, and coronal thirds of the roots, and digital image correlation was used to evaluate shrinkage during free convection. Crack initiation and growth analysis was performed via optical microscopy, and bound water in dentin was characterized by Raman spectroscopy.ResultsThe rate of shrinkage was significantly higher (p ≤ .05) in the apical third than in the middle and coronal thirds of all teeth regardless of donor age. The highest shrinkage strain occurred in the apical third of old donor teeth with prior RCT. In addition, the RCT-treated old teeth suffered the highest percentage of water loss with dehydration. Cracks initiated from the root surface and extended toward the canal with loss of water and shrinkage.ConclusionsThe apical third undergoes significantly larger shrinkage strains with dehydration than the remainder of the root. Prior RCT exacerbates the extent of shrinkage, particularly in the teeth of seniors and after clinical function, which could increase the propensity for VRF.     

Evaluation of Related Factors in the Failure of Endodontically Treated Teeth: A Cross-sectional Study

Introduction

The aim of this study was to review the factors related to the failure and extraction of unsuccessful endodontically treated teeth.

Periapical Status Related to the Quality of Coronal Restorations and Root Fillings in a Korean Population

Introduction

The purpose of this study was to assess the prevalence of apical periodontitis in root canal–treated teeth from the Korean population and to evaluate the relationship between the quality of root canal fillings and coronal restorations and the periapical status of these teeth.

Methods

Full-mouth periapical radiographs at the Dental Hospital of Yonsei University, Seoul, South Korea, were examined. A total of 1030 endodontically treated teeth restored with full veneer crown–type restorations were evaluated by 2 independent examiners. Teeth were classified as healthy or diseased according to the periapical status. The quality of endodontic treatment and coronal restorations were also classified via radiographic and clinical evaluation. The data were analyzed using the chi-square test and logistic regression.

Results

Forty-one percent of all endodontically treated teeth were classified as diseased. Approximately 35.6% of the teeth had endodontic treatments that were rated as adequate. The diseased teeth rate for cases with adequate endodontic treatment was 24.5%, which was significantly lower when compared with teeth with inadequate endodontic treatment (49.9%). The number of teeth with adequate coronal restorations was 706 (68.5%). Teeth with adequate coronal restorations had a significantly decreased prevalence of diseased teeth (34.7%) compared with teeth with inadequate coronal restorations (54.3%). Teeth with both adequate root fillings and restorations showed a significantly better outcome (82.3%) than the others, and teeth with both inadequate root fillings and restorations showed a significantly worse outcome (41.2%) than the others.

Conclusions

Data from this Korean population showed a relatively high prevalence of apical periodontitis. The quality of endodontic treatment and coronal restorations were of equal importance and were strong independent predictors of the periapical status.     

Periapical Inflammation Subsequent to Coronal Inoculation of Dog Teeth Root Filled with Resilon/Epiphany in 1 or 2 Treatment Sessions with Chlorhexidine Medication

Introduction

Therapeutic methods that inhibit microbial ingress into filled root canals are desirable. This in vivo study assessed the inhibition of periapical inflammation subsequent to coronal inoculation in canals medicated with 2% chlorhexidine gel and filled with Resilon/Epiphany (Pentron Clinical Technologies, Wallingford, CT).

Methods

Six Beagle dogs each had 10 two-rooted premolars treated. In group 1 (n = 36 roots), 1 root/tooth had the canal conditioned with Primer Epiphany, filled with Epiphany sealer and Resilon core in 1 session, and coronally sealed with PhotacFil. In group 2 (n = 36 roots), the second root/tooth had the canal medicated with 2% chlorhexidine gel for 1 week and then filled and coronally sealed as in group 1. After 3 weeks, canals were exposed to the oral environment for 7 days, inoculated with isologous plaque, and coronally sealed. Negative controls treated as groups 1 and 2 remained sealed. Positive controls had canals unfilled and exposed. Seven months after inoculation, dogs were euthanized; jaw blocks processed for histologic examination; and periapical inflammation (PI) recorded as none, mild, or severe.

Results

In groups 1 and 2, severe PI occurred in 5 of 65 roots (8%) and mild PI in 18 of 65 roots (28%) with a significantly higher (P = .031) PI incidence in group 2 than in group 1. Negative controls had only mild PI in 9 of 29 roots (31%). Roots medicated with 2% chlorhexidine gel had mild PI significantly more (P = .009) than roots filled in 1 session (more than 2-fold).

Conclusions

Intracanal medication with 2% chlorhexidine gel and root filling with Resilon/Epiphany did not effectively inhibit apical periodontitis subsequent to coronal inoculation.     

In Vitro Fracture Resistance of Endodontically Treated Roots Filled with a Bonded Filling Material or Different Types of Posts

AimThis study aimed to compare the fracture resistance of roots filled with a bonded material, fiber posts, or titanium post systems.MethodsCanals in the first group were filled with AH Plus and gutta-percha cones, and roots in the second group were filled with Epiphany sealer and Resilon cones. The root fillings (60 roots) were removed up to 4 mm from the canal apex to obtain 10-mm-deep post spaces, and posts were cemented. The groups were as follows: AH Plus control group, Epiphany control group, AH Plus fiber post group, AH Plus titanium post group, Epiphany fiber post group, and Epiphany titanium post group. Fracture tests were performed by using an Instron testing machine. The force was applied at a 45° axial angle with a constant speed of 1 mm/min. For each sample, the force at which fracture occurred was recorded in units of newtons. Statistical analysis was carried out by using analysis of variance test.ResultsThere was no statistically significant difference between all groups (P > .05).ConclusionsTitanium posts, fiber posts, and Epiphany root canal filling systems were found to have no reinforcing effect on endodontically treated roots.