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目的探讨根管再治疗的技术及方法。方法选取2005年7月至2006年8月于东南大学医学院附属徐州中心医院口腔科就诊的38例患者共46颗需根管再治疗的患牙,采用小号K型锉配合次氯酸钠溶液和乙二胺四乙酸二钠(EDTA)溶液探查根管并清理根管内感染物质,封入氢氧化钙糊剂1～2周,采用手用镍钛器械ProTaper进行根管预备,侧向加压技术充填根管,记录治疗过程中患牙症状的改善程度、根管疏通情况、根管预备和充填效果。结果45颗患牙根管疏通成功,治疗过程中症状明显缓解或完全消失,瘘管明显减小或消失,根管预备时无根管偏移、根尖阻塞、台阶等并发症发生,根管形态良好。结论根管再治疗时应强调彻底清除根管内感染物质。采用次氯酸钠和EDTA溶液清理根管,氢氧化钙消毒根管,器械ProTaper进行根管预备能取得良好的治疗效果。     

ProTaper机用锉行干髓治疗失败患牙根管治疗的护理体会

目的总结ProTaper机用镍钛锉行干髓治疗失败患牙根管治疗的护理配合体会。方法干髓术失败的患者67例,磨牙89颗,先用10～15号不锈钢K锉探查根管,配合次氯酸钠和乙二胺四乙酸冲洗液,清理根管内的感染物质,然后用ProTaper机用镍钛锉进行根管预备,并实施规范熟练的护理配合,以缓解患者在根管治疗中的疼痛与恐惧。结果 67例89颗患牙的根管疏通成功,预备的根管无根管偏移、根尖阻塞、台阶等并发症发生,根管形态良好,根管治疗后临床症状明显缓解或完全消失。结论掌握根管治疗的护理配合步骤、熟悉机用镍钛锉预备根管的方法,才能更迅速、准确地配合医生使用ProTaper机用镍钛锉完成根管治疗,提高工作效率。     

手术显微镜联合超声技术在塑化根管再治疗中的应用评价

目的:评价手术显微镜联合超声技术在塑化根管再治疗中的应用。方法:选取曾进行过塑化治疗的患牙63颗,在手术显微镜下,采用超声根管锉疏通塑化根管的上段,小号手用K锉配合EDTA溶液逐步疏通根管下段,机动镍钛器械Hero642完成根管预备,侧向加压充填法充填根管,观察并评价疗效。结果:54颗患牙的根管疏通成功,并完成根管治疗,根管再通成功率为85.7%。治疗过程中无牙根折裂、台阶形成、根管壁侧穿或器械折断发生。结论:手术显微镜和超声器械去除根管内塑化物快速高效,可作为临床上处理塑化再治疗患牙的有效方法,但不推荐将超声器械用于根管的下段或弯曲部位。     

根管显微镜联合超声技术在塑化根管再疏通中的应用

目的:评价根管显微镜联合超声技术在塑化根管再疏通中的应用。方法:选取曾进行过塑化治疗的患牙77颗,在根管显微镜下,采用超声根管锉、超声工作尖疏通塑化根管上段,再用根管扩大器扩大及EDTA疏通根管下段,机用镍钛器械预备根管,完成根管充填,X线片评价根管再疏通效果。结果:190个塑化根管169个根管疏通成功,再疏通成功率88.9%。治疗过程中无牙根折裂、根管壁侧穿或器械折断发生。结论:根管显微镜联合超声器械去除根管内塑化物快速、有效。     

上颌第一磨牙近颊第二根管的临床治疗

目的 探讨上颌第一磨牙近烦第二根管（second mesiobuccal canal，MB2）的特征及临床治疗方法。方法 选取患牙髓炎或根尖用炎的上颌第一磨牙95颗，拍摄术前X线片，术中采用小号K锉配合15％EDTA溶液探查根管，记录根管数目、形态和类型；采用机动镍钛器械Hero642进行根管预备，侧向加压充填技术充填根管。结果上颌第一磨牙MB2的发现率为81．1％，扩通的MB2占72．6％，多数MB2根管细小弯曲，需用小号锉配合使用EDTA进行疏通，机动镍钛器械预备根管无明显并发症。结论上颌第一磨牙MB2的发生率高，多数根管细小弯曲，小号K锉配合EDTA疏通根管，机动镍钛器械预备可获得良好的治疗效果。     

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目的评价MTWO镍钛根管预备系统在磨牙根管治疗中的应用效果。方法选取2008年1月至2009年2月解放军第463医院口腔科门诊收治的需做根管治疗的患者110例(126颗患牙),随机分成2组,试验组72颗,对照组54颗;分别采用MTWO镍钛根管预备系统和不锈钢K锉行根管预备,次氯酸钠溶液和EDTA凝胶疏通并清理根管内感染物质,采用侧向加压技术行根管充填;根据临床操作时间、术后X线片及疼痛情况评价根管预备和充填的效果。结果试验组根管预备平均时间为4min10s,明显少于对照组的10min50s;试验组无根管偏移及台阶形成,能较好地保持根管的解剖初形,对照组中2例有台阶形成;试验组适充率(94.4%)明显高于对照组(81.5%)(P<0.01),术后3d疼痛的发生率(4.2%)明显低于对照组(13.0%)(P<0.01)。结论用MTWO镍钛根管预备系统预备根管能很好地维持根管解剖形态,减少术后疼痛,并且省时、高效,提高了根充效果。     

根管治疗处理牙髓治疗失败牙的疗效观察

根管治疗是牙髓根尖周病的治疗方法之一,进行根管治疗需要精湛的技术和先进的设备\+\{［1］\}。发达国家对牙髓根尖周病主要采用根管治疗术。目前我国仍多种治疗方法并存,牙髓治疗失败率较高。本文就近年收集的162例牙髓治疗失败患牙进行病因分析、再处理及临床疗效观察。 1 材料和方法 1．1 病例选择 选择1996～1998年间中山医科大学口腔医学院牙体牙髓科就诊的148例、162颗牙髓治疗失败患牙（纵折除外）。出现下述任何一项即为牙髓治疗失败：①治疗后6～24个月出现骨质破坏或骨质破坏区扩大;②瘘管未消失;③治疗6个月后仍诉疼痛和肿胀。患牙原治疗情况及牙位分布见表1。 1．2 方法 再处理：①充分揭开髓顶,清理髓腔、根管。对曾行干髓术者,彻底清除干髓剂及根管内残余牙髓等;曾行塑化治疗者,采用乙二胺四乙酸（EDTA）辅助清除髓室和根管内塑化物等;曾行根管治疗者,用氯仿溶解、去除原充填物。②利用镍钛根管器械（Profile 系列）及超声根管治疗仪（Odontoson M ,丹麦）进行常规法或逐步后退法（弯曲根管）预备根管。③用Spreader侧压器进行不加热侧方加压法充填根管。 牙髓治疗失败患牙经再处理后,充填成功牙每3个月复查1次,作临床检查及X线片复查,随访2年。     

Mtwo镍钛器械在钙化阻塞根管治疗中的应用

目的:对Mtwo镍钛器械处理钙化阻塞根管的疗效进行评价.方法:选取21例35个用C型先锋锉结合EDTA凝胶疏通治疗失败的钙化阻塞根管,应用10#Mtwo镍钛器械结合EDTA凝胶进行钙化疏通处理,观察根管疏通成功率和根管内并发症发生率.采用SAS 9.4软件包对数据进行统计学分析.结果:成功疏通23个钙化阻塞根管,成功率为65.71％.4个根管(11.43％)发生器械分离,3个根管(8.57％)形成根管台阶.按不同钙化部位分为3组,成功率无显著差异(P＞0.05).结论:Mtwo镍钛器械可提高钙化阻塞根管的治疗成功率.     

下颌第二磨牙C形根管的特点和临床治疗

目的探讨下颌第二磨牙C形根管的发生率、临床诊断和治疗方法。方法通过对152例下颌第二磨牙拍摄术前X线片和术中根管探查,按照Melton标准诊断C形根管;采用机用镍钛器械Hero642进行根管预备,次氯酸钠超声冲洗,热牙胶垂直加压技术充填根管。记录C形根管的发生率及临床特点,根据治疗前、中、后的X线片评价根管预备和充填的效果。结果下颌第二磨牙C形根管的发生率为32.2%,79.6%的C形根管患牙X线片表现为锥形融合牙根,20.4%表现为近、远中独立牙根;所有患牙均无根管内并发症发生,治疗效果好。结论下颌第二磨牙C形根管主要存在于融合牙根,根管探查结合X线片可诊断C形根管;机用镍钛器械预备根管、次氯酸钠超声冲洗和垂直加压技术充填根管可获得良好的治疗效果。     

机用镍钛器械ProTaper用于根管治疗的临床研究

目的：评价使用机用镍钛器械ProTaper预备根管的临床效果。方法：选取临床上患牙髓炎及根尖周炎需要进行根管治疗的患牙162个,其中83个运用冠向下技术,机用镍钛器械ProTaper进行根管预备,热牙胶垂直加压技术充填根管;另外79个患牙运用逐步后退法根管预备技术,国际标准手动不锈钢K锉进行根管预备,冷侧压技术充填根管。记录两组根管预备所需时间及器械折断数量,根据治疗前、中、后的X线片评价预备及根充效果。结果：用机用镍钛器械ProTaper根管预备组所有患牙根管锥度流畅度好,根管形态及工作长度无改变,操作时间短,有3例发生器械折断。结论：使用机用镍钛器械ProTaper预备根管成形、根充效果好,时间短,但要注意预防器械的折断。     

Dentinal tubule penetration of root canal sealers after root canal dressing with calcium hydroxide.

The purpose of this study was to evaluate the dentinal tubule penetration of root canal sealers after root canal dressing with calcium hydroxide (Ca(OH)2). Forty-two single-rooted teeth were instrumented to size 60. Six teeth served as the control group, and the remaining teeth were assigned to two groups. Root canals of the first group were filled with the Ca(OH)2 paste; the second group was filled with TempCanal, and all were incubated for 7 days. The samples were either irrigated with only NaOCl or with EDTA, followed by NaOCl to remove Ca(OH)2. All of the teeth were obturated with CRCS, AH26, and Ketac Endo by a lateral condensation technique. The specimens were then kept at the same conditions for another 7 days, and then all of the roots were prepared for scanning electron microscopic evaluation. Scanning electron microscopic examination revealed that Ca(OH)2 was not completely removed from the root canal surfaces, and root canal sealers did not penetrate into the dentinal tubules when only NaOCl was used. EDTA followed by NaOCl irrigation resulted in complete removal of Ca(OH)2 and root canal sealers penetrated into the dentinal tubules.     

The influence of preparation technique and sodium hypochlorite on removal of pulp and predentine from root canals of posterior teeth

AIM: To test the null hypothesis that removal of pulp tissue and predentine from root canals of multirooted teeth is not significantly different when performed by one of two mechanical preparation techniques in conjunction with either water or 3% sodium hypochlorite (NaOCl) irrigation. METHODOLOGY: Forty-six freshly extracted premolar or molar teeth, with pulps vital at the time of extraction, were assigned to four groups balanced by anatomy (group 1, step-back filing/NaOCl; group 2, step-back filing/water; group 3, automated rotary/NaOCl; group 4, automated rotary/water). Preparation was undertaken by a single operator and the volumes of irrigant recorded for each tooth. One root from each tooth was prepared for transverse histological assessment at eight levels, including one at and two apical to the working length. A validated index was used to measure the presence and location of residual pulp tissue and predentine. RESULTS: No statistically significant differences were found in the frequency with which residual pulp tissue or predentine were observed amongst the groups. Coronal parts were more frequently devoid of pulp tissue and predentine than the apical. Canals were frequently occluded with residual pulp tissue apical to the working length. There was a trend for better pulp and predentine removal in accessible parts of the canal as a function of rotary preparation and NaOCl irrigation. The isthmus had residual pulp tissue less frequently in the NaOCl groups. Accessory anatomy was unaffected regardless of technique or irrigant. CONCLUSIONS: Pulp tissue and predentine removal were not significantly different between a step-back filing and an automated rotary preparation technique in conjunction with water or NaOCl.     

Detection and eradication of microorganisms in root-filled teeth associated with periradicular lesions: an in vivo study

This study determined the presence of microorganisms by culture and polymerase chain reaction in asymptomatic root-filled teeth with periradicular lesions. Furthermore, a disinfecting regimen using sodium hypochlorite (NaOCl), ethylenediaminetetraacetic acid (EDTA), chlorhexidine digluconate (CHX) irrigation, and calcium hydroxide (Ca(OH)(2)) dressing was assessed. After removal of the root-filling material, specimens of 20 cases undergoing retreatment were sampled. Moreover, the canals were sampled after each step of the disinfecting regimen. Prevalence of microorganisms was 60% by culture and 65% by polymerase chain reaction. In four of those samples (31%), DNA of Enterococcus faecalis was found. After further root canal preparation and irrigation using NaOCl and EDTA, microorganisms could be detected in none of the teeth. Thus, CHX and Ca(OH)(2) could not show further disinfection. In contrast, microorganisms were found in two teeth after the interappointment dressing. It may be concluded that proper root canal preparation and irrigation using NaOCl and EDTA are sufficient for decontamination of the root canal system during endodontic retreatment.     

Reduction in intracanal bacteria during root canal preparation with and without apical enlargement

AIM: To compare in vitro intracanal bacterial reduction using nickel-titanium rotary instruments with and without apical enlargement. METHODOLOGY: Thirty-eight palatal roots of maxillary molar teeth, with mature apices were subdivided according to lengths and then randomly assigned to two experimental and one control groups. The roots were sterilized and then reinfected with Enterococcus faecalis, which served as a bacteriological marker. All roots in the experimental groups were prepared in a step-down sequence with engine-driven GT rotary files at 350 rpm. In experimental group A (n = 16) additional apical enlargement to ISO size 35 was performed. In group B (n = 16) a serial step-back technique was followed with no apical enlargement. This was combined in groups A and B with irrigation with NaOCl and EDTA. In the control group (group C, n = 6) irrigation only was carried out, with no mechanical preparation. Samples were then taken from the root canals to determine the numbers of remaining bacteria. RESULTS: In groups A and B, 15 (94%) and 13 (81%) specimens were rendered bacteria-free, respectively. In the control group C none of the specimens were bacteria-free. There was a significant difference (P < 0.001) in the antibacterial effects of experimental and control regimens. There was, however, no significant difference (P = 0.276) between the preparation methods used in the experimental groups. CONCLUSIONS: There was no significant difference in intracanal bacterial reduction when Ni-Ti GT rotary preparation with NaOCl and EDTA irrigation was used with or without apical enlargement preparation technique. It may therefore not be necessary to remove dentine in the apical part of the root canal when a suitable coronal taper is achieved to allow satisfactory irrigation of the root canal system with antimicrobial agents.     

Ex vivo analysis of the debris remaining in flattened root canals of vital and nonvital teeth after biomechanical preparation with Ni-Ti rotary instruments

The purpose of this study was to assess the presence of apical debris remaining in the apical third of flattened root canals of vital and nonvital teeth after biomechanical preparation with Ni-Ti rotary instruments. Fresh-extracted human mandibular incisors were used in this study. The teeth had clinical indication for extraction and were submitted to cold pulp vitality testing and radiographic examination. Eighteen teeth were selected and randomly assigned to two groups (n=9), according to the clinical diagnosis, i.e., pulp vitality or pulp necrosis. The canals were instrumented with the ProTaper NiTi rotary system in the following sequence: S1--up to the middle third; SX--at the cervical third; S2--up to the apical third; and S1, F1, F2, F3--at the working length. The canals were irrigated with 1% sodium hypochlorite, dried and were submitted to the histological processing. Sections from the apical third were analyzed by an optical microscope (X40) that was coupled to a computer where the images were captured and analyzed using specific softwares. A grid was placed over these images to assess the total canal area and the areas with debris. Mann-Whitney U-test showed no statistically significant difference (p>0.05) between the teeth with pulp vitality (6.49 +/- 3.39) and those with pulp necrosis (5.95 +/- 2.22). It may be concluded that the clinical condition of pulp tissue did not interfere with the amount of debris remaining in the apical third of flattened root canals prepared with Ni-Ti rotary instruments.     

Calcium hydroxide root canal dressing. Histopathological evaluation of periapical repair at different time periods

The objective of this study was to evaluate periapical and apical repair using calcium hydroxide root canal dressings for different lengths of times in teeth with induced chronic periapical lesions. A total of 61 root canals of maxillary and mandibular premolars from 4 dogs were used. After mechanical preparation of the root canals using the crown-down technique, and 5.25% NaOCl as irrigating solution, the apical foramen was enlarged in all cases. A calcium hydroxide root canal dressing was applied. The control group did not receive a root canal dressing. The animals were killed at 7, 15 or 30 days. After histological preparation, serial sections were stained with hematoxylin-eosin and Mallory's trichrome. The best histopathological results occurred at 15 and 30 days, and the worst results occurred at 7 days and in the control group.     

钙化根管的根管显微镜治疗

目的:探讨应用根管显微镜治疗钙化根管的方法,并对其疗效进行评价.方法:因根管钙化进行根管治疗的患牙33个,在根管显微镜引导下,将超声预备、手动NiTi器械预备以及EDTA化学预备相结合进行治疗,记录预备时间,术后1周进行根管充填,半年后复查并进行疗效评价.结果:根管显微镜下钙化根管的治疗成功率为88.9%,平均每根根管耗时25.8 min.结论:在根管显微镜引导下,将超声预备、手动NiTi器械预备以及EDTA化学预备相结合可提高钙化根管治疗的成功率.     

倒敞法结合2 种机用镍钛锉预备重度弯曲后牙根管的应用研究

目的:评价倒敞法结合Hero 642和ProTaper机用镍钛锉预备重度弯曲后牙根管的疗效.方法: 随机将100 颗患牙髓炎或根尖周炎、最大根管弯曲度≥25°的后牙分为2 组,各50 例.实验组(A组)采用倒敞法,而对照组(B组)不采用倒敞法机械预备.A组以机用开口锉根管中上端敞开后,手用K锉预备根尖,再先用镍钛器械Hero 642,后用ProTaper预备根管;B组则直接应用Hero 642和ProTaper冠向下法预备根管. 2 组均用侧压法充填根管.根据X线片情况,预备时间,器械折断、疼痛等并发症,评价根管预备和充填的疗效,1 年随访率95%.结果:A组倒敞法结合Hero 642和ProTaper机用镍钛锉预备重度弯曲后牙根管,锥度、流畅度好,术后疼痛少且程度轻,无器械折断;而B组发生器械折断3 支(P>0.05);充填恰充率、欠充率、流畅度、术后疼痛两者有显著性差异(P<0.05).结论: 倒敞法结合Hero 642和ProTaper机用镍钛锉预备重度弯曲后牙根管,成形、根充效果好,并发症少,最大限度发挥了各自优点,是预备重度弯曲后牙根管值得推广应用的有效方法.