预备桩时对根尖封闭的影响

根管治疗牙通常用桩、核和人造冠修复,预备桩时破坏了根尖1/3的充填物可影响根尖封闭。关于桩的长度,许多学者提出:桩应与冠等长,桩为根长的1/2或为根长的2/3、4/5,桩的可能长度应不影响根尖封闭等,但都没有提供适当的根尖封闭需要保留牙胶的长度。预备桩时去除牙胶的方法同样是重要的。有人发现用溶剂和扩孔钻去牙胶可引起充填物的收缩而影响根尖封闭。有人研究了用热的根管充填器预备根管对根尖封闭的影响。有学者指出用侧向凝聚的牙胶作根管封闭和用Peeso扩孔钻预备根管没     

不同根管预备方法对直根管即刻桩腔预备根尖封闭性影响的研究

目的观察直根管不同根管预备方法根管充填后即刻桩腔预备对根尖封闭性的影响。方法离体直单根管上前牙84个,其中80个按根管预备方法随机平均分为2组(n=40),A组:不锈钢根管锉常规法;B组:G型钻根管冠部预处理+不锈钢根管锉常规法,其余4个随机平均分配为阴性对照组和阳性对照组。所有根管均用侧方加压法充填,即刻垂直加压器去除部分充填材料,然后P型钻桩腔预备。用染料渗透法评价各组根尖封闭能力。结果B组的根管进行即刻桩腔预备后,其根尖微渗漏较A组轻(P<0.05)。结论大锥度根管预备,根管充填后即刻桩腔预备根尖封闭性较好。     

根充时预留桩道桩冠修复的临床疗效研究

根管充填治疗后桩核冠修复是牙体缺损修复的重要方法之一,通常在根充完成2周后行根管预备,以避免并发症的发生并有助于桩道预备时根充材料的取出。但桩道预备过程会破坏根管上段封闭,形成微渗漏,甚至破坏根尖封闭,造成微生物进入,引起根尖周组织感染。近年来随着热压充填技术的发展,使根充的同时预留桩道成为可能。     

桩道预备后剩余根管充填物的根尖封闭作用评价

目的:比较不同根管充填方法及桩道预备后不同长度的充填材料对根尖的封闭作用,寻找根管充填方法和剩余充填材料的最佳搭配选择,为临床应用提供理论依据.方法:132颗单根管牙随机分为6个实验组(每组各20颗)和2个对照组(每组各6颗).根管预备后A、B、C3组行冷牙胶侧方加压充填,桩道预备后分别剩余4、6、8 mm根管充填物;D、E、F3组行连续波热牙胶充填,桩道预备后分别剩余4、6、8 mm根管充填物;G组(阴性对照组)随机选择不同充填方法及不同长度剩余根管充填物:H组不进行根管充填.利用葡萄糖定量检测微渗漏模型,检测各组从冠方向根方渗漏的葡萄糖浓度(体积).采用SPSS 19.0软件包对数据进行统计学分析.结果:A和D、B和E、C和F比较,冷牙胶侧方加压充填组微渗漏显著大于热牙胶充填组.A和B、A和C、D和E、D和F相比,差异均具有显著性;B和C、E和F相比,无显著差异,说明根尖剩余4 mm和6 mm组间具有显著差异,而剩余6 mm和8 mm组间无显著差异.结论:连续波热牙胶充填技术的根尖封闭性能显著优于冷牙胶侧方加压法.桩道预备后剩余6 mm微渗漏较少.是较合适的剩余充填材料长度.     

即刻桩腔预备对三种根管预备方法预备的直根管根尖封闭性的影响

目的 研究三种不同根管预备方法根管预备、根管充填后即刺桩腔预备对直根管根尖封闭性的影响.方法 离体直单根管上前牙124个,其中120个随机平均分为3组(n=40),A组:不锈钢根管锉常规法;B组:G 型钻根管冠部预处理 不锈钢根管锉常规法;C组:手用Pr01raper镍钛根管锉冠向下法,刺余4个随机平均分为阴性对照组和阳性对照组.所有根管均用侧方加压法充填,即刻手持垂直加压器去除部分充填材料,然后P型钻桩腔预备.用染料渗透法评价各组根尖封闭能力.结果 B组G型钻根管冠部预处理 不锈钢根管锉常规法预备的根管和C组手用ProTaper镍钛根管锉冠向下法预备的根管即刻桩腔预备后,其根尖微渗漏较A组常规法预备的轻(P<0.05).结论 大锥度根管预备,根管充填后即刻桩腔预备的根尖封闭性较好.     

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。     

桩腔预备后剩余充填材料封闭根管能力的实验研究

目的:采用葡萄糖微渗漏模型检测桩腔预备后剩余充填材料封闭根尖的能力。方法:选取70颗单根管上颌前牙,随机分为4个实验组和2个对照组。采用逐步后退技术预备根管,AHp lus糊剂和牙胶尖侧向加压充填根管,然后G钻进行桩腔预备。实验组根管内剩余充填物长度分别为3、5、7、10 mm。用葡萄糖微渗漏模型检测第1、2、3和4周根管冠根向渗漏出的葡萄糖量。结果:实验第1周各组的葡萄糖微渗漏值无显著性差异(P>0.05),第2周起,第1组的微渗漏值高于第3、4组(P<0.05),而第1、2组之间无显著性差异(P>0.05)。结论:在保证桩核固位的前提下,应尽量多的保留根管内剩余充填物的长度。     

桩道预备对两种新型根管充填剂封闭性的影响

目的液体转移法评价根管桩道预备对两种新型根管糊剂充填后根尖封闭性的影响。方法 24颗人上颌前牙截冠后统一工作长度为16mm,进行根管预备。样本随机分组为Endofill组、Acroseal组和AH Plus组(对照组),每组8个样本。根管充填1周后液体转移法测量桩道预备前根管微渗漏。随后1-6号G钻逐步桩道预备,保留根尖4mm充填物。再次测量桩道预备后的根管微渗漏。实验数值采用SPSS 13.0统计学软件进行霍特林T2检验,取α=0.05。结果桩道预备增加Endofill组的根尖微渗漏,差别有统计学意义(P<0.05)。桩道预备不影响Acroseal组和AH Plus组的根尖微渗漏(P>0.05)。结论桩道预备降低了Endofill的根尖封闭性。建议Endofill慎用于需桩核冠修复的根管充填。     

根管充填材料和根管充填技术规范

根管治疗术是通过清除根管内的坏死物质,进行适当的消毒后严密充填根管三维系统,以去除根管内容物对根尖周围组织的不良刺激,防止发生根尖周病变或促进根尖周病变愈合的一种治疗方法.根管充填是根管治疗的关键步骤之一,在根管经严格的预备、消毒后,通过严密的三维封闭,有效消灭死腔,杜绝再感染,达到根管治疗的最终目的.     

连续波热牙胶充填后不同时机桩腔预备对根尖封闭性的影响

目的 评价连续波热牙胶充填后不同时机桩腔预备对根尖封闭性的影响。方法 50颗单根管牙,采用冠向下法,使用ProTaper机用镍钛系统预备根管。随机选择5颗牙为阴性对照组,5颗牙为阳性对照组。另40颗牙随机分为A、B、C、D4组,每组10颗,所有根管均使用连续波热牙胶充填术充填根管,阳性对照组不使用根管封闭剂,然后A、B、C、D组分别于根充后即刻、3d、7d、30d四个不同时间点进行桩腔预备。采用葡萄糖定量法测定第2、7、14、21、28d从冠方向根方渗漏的葡萄糖量。结果 从第14d起即刻桩腔预备组与延迟桩腔预备三组相比,葡萄糖渗漏量均有显著性差异(P<0.05),而实验期间延迟桩腔预备三组之间相比没有统计学差异(P>0.05)。结论 延迟桩腔预备会削弱充填材料和封闭剂封闭根管的能力。     

A radiographic comparison of two root canal instrumentation techniques.

The ability of two instrumentation techniques to negotiate and enlarge small curved canals was com-compared radiographically. Fifty canals in extracted human molar teeth were instrumented by the progressive enlargement (PE) technique, a form of step-back preparation using standard K files, or by the balanced force (BF) technique using K files whose tips had been specially modified. By using drawings and projected radiographic images of the files, the position of the largest file used in the apical preparation, #30 or #35 for the PE technique and #45 for the BF technique, was compared with the position of a small file placed in the canal before instrumentation. The PE and BF techniques were equally capable of instrumenting small curved canals to their respective largest apical preparation sizes. However, at sizes equivalent to the largest apical preparation sizes used in the PE technique, the BF technique produced significantly less deviation from the center of the original canal.     

A micro-computed tomographic evaluation of apical root canal preparation using three instrumentation techniques

Aim  To investigate the morphological changes in the apical third of the root canal after preparation with three techniques.
Methodology  Forty molar teeth were scanned using micro-computed tomography before and after instrumentation with: Group 1 – stainless steel K-files using the balanced force technique; Group 2 – stainless steel K-files (balanced force) and then refining the apical preparation with the equivalent size 0.04 taper FlexMaster instrument; Group 3 – a hybrid ProTaper/FlexMaster (ProFile for sizes 45 and 60) sequence. Eight canals were excluded because of artefacts in the images or unnegotiable blockages leaving 110 canals that could be analysed. Apical root canal preparation was evaluated with respect to the amount of dentine removed, canal roundness, transportation and how the dimensions of the prepared apical root canal correlated with those of the final instrument used.
Results  The median apical preparation sizes for the three groups respectively were: 30, 30 and 40. Despite the larger size and less experienced operator, the volumetric change (the amount of dentine removed) in canals prepared with a hybrid rotary nickel–titanium instrumentation technique remained small and, a more rounded preparation ( P  < 0.001) that closely matched the final instrument dimensions ( P  < 0.001) was produced. There was a trend for less canal transportation using rotary nickel–titanium instruments.
Conclusions  Stainless steel hand preparation was not conservative of apical dentine. When used correctly, even by less experienced operators, rotary nickel–titanium instruments were able to precisely 'machine' a canal to larger apical sizes with minimal risk of iatrogenic damage.     

ProTaperNext锉和WaveOne锉根管成形能力的对比研究

目的:比较机用ProTaperNext和WaveOne在弯曲树脂模拟根管中的成形能力。方法:选取统一规格的透明树脂模拟根管40个,将其随机分为2组,分别使用ProTaperNext和WaveOne锉以冠向下技术预备两组树脂模拟根管。使用ImagePro Plus软件测量根管弯曲半径和弯曲度的变化以及各测量点去除树脂量,计算树脂去除总量和两组器械的中心定位力,同时记录和分析根管工作长度的变化和器械变形、分离等参数。结果:两种器械预备根管时,均能保持较好的工作长度,不易发生器械分离,能够较好的维持根管原始走形,但在根尖段,WaveOne预备后的根管较易发生偏移。结论:ProTaperNext与WaveOne相比,在预备重度弯曲根管时具有良好的根管成形能力。     

Root canal retreatment or surgical apicoectomy?

Failure of root canal therapy is usually due to re-infection of the root canal system. In most of these cases, an endodontic retreatment is indicated. Patients with persisting apical periodontitis frequently are referred to an oral surgeon for apical surgery, although endodontic retreatment would have been possible in a majority of these cases. When endodontic retreatment is not possible or does not resolve the patient's problems, surgical apicoectomy or extraction might be the only possibilities left. Apical surgery is usually performed by an oral sugeon or by a specially trained dentist. In most surgical clinics beveled resection, followed by an preparation and restoration is performed. New developments, such as microscopic sugery, ultrasonic preparation and newly developed restorative materials are described in this article. Since there is a lack of well-designed comparative clinical studies, no definite conclusions can be drawn with regard to the clinical value of these modern techniques.     

连续波热牙胶充填技术根尖封闭性能的评估

目的体外实验比较不同器械预备根管后连续波热牙胶根管充填技术的根尖封闭能力。方法离体双根管上颌前磨牙随机分为机用ProFile预备组和不锈钢K锉预备组,分别采用连续波热牙胶充填技术和冷侧压法进行根管充填,用染料渗透法和透明标本法测量根尖微渗漏,评价各组根尖封闭能力。结果各组根尖微渗漏距离无统计学差异(P>0.05)。结论连续波热牙胶充填技术与冷牙胶侧方加压充填技术的根尖封闭能力无显著性差异;对直根管和轻度弯曲的根管,不同器械根管预备后其根管充填效果无明显影响。     

Sinus floor elevation via the maxillary premolar extraction socket with immediate implant placement: a case series

Background: When immediate implant placement is considered for teeth with close proximity to the sinus floor, apical extension of the osteotomy is significantly limited, and often a staged approach is used. Implant placement into fresh extraction sockets and sinus floor manipulation using bone‐added osteotome sinus floor elevation with implant placement are techniques most often used independently or sequentially. Very few reports have described the combined use of immediate implant placement in fresh sockets and the bone‐added osteotome sinus floor elevation technique. Methods: We present five cases in which a maxillary premolar was extracted and an implant placed into the extraction site with simultaneous abfracture of the sinus floor using osteotomes. All teeth were extracted atraumatically, and sockets carefully debrided and checked for integrity of the walls. After ideal osteotomy preparation, particulate bone graft was placed in the osteotomy and appropriately sized osteotomes were used for sinus floor elevation. After sufficient elevation, implant placement was completed and particulate bone was packed in the bone–implant gap when indicated. Results: All implants were restored after a minimum healing period of 6 months. At the time of final restoration, bone was seen surrounding the implants from the apical portion to the most coronal thread. All five implants healed without complications and were in function for periods ranging from 6 to 12 months. Conclusions: Immediate implant placement with simultaneous osteotome sinus floor elevation is an advantageous combination of two successfully used techniques. This combined approach can significantly reduce the treatment time for implant therapy in teeth with close sinus proximity and provide the operator with the ability to place implants of desired length.     

后牙弯曲根管充填方法的根尖封闭能力研究

本实验用常规法、逐步后退法和超声法三种方法预备后牙弯曲细小根管，再分别用传统侧压充填法和热侧压充填法进行充填，然后比较其根尖封闭能力。结果表明：热侧压充填法的根尖封闭能力优于传统的侧压充填法，并能在一定程度上弥补常规法和超声法预备弯曲细小根管成形不佳的缺陷，增加其根尖封闭能力     

Evaluation of three instrumentation techniques at the precision of apical stop and apical sealing of obturation

Objective

The aim of this study was to investigate the ability of two NiTi rotary apical preparation techniques used with an electronic apex locator-integrated endodontic motor and a manual technique to create an apical stop at a predetermined level (0.5 mm short of the apical foramen) in teeth with disrupted apical constriction, and to evaluate microleakage following obturation in such prepared teeth.

Material and Methods:

85 intact human mandibular permanent incisors with single root canal were accessed and the apical constriction was disrupted using a #25 K-file. The teeth were embedded in alginate and instrumented to #40 using rotary Lightspeed or S-Apex techniques or stainless-steel K-files. Distance between the apical foramen and the created apical stop was measured to an accuracy of 0.01 mm. In another set of instrumented teeth, root canals were obturated using gutta-percha and sealer, and leakage was tested at 1 week and 3 months using a fluid filtration device.

Results

All techniques performed slightly short of the predetermined level. Closest preparation to the predetermined level was with the manual technique and the farthest was with S-Apex. A significant difference was found between the performances of these two techniques (p<0.05). Lightspeed ranked in between. Leakage was similar for all techniques at either period. However, all groups leaked significantly more at 3 months compared to 1 week (p<0.05).

Conclusions

Despite statistically significant differences found among the techniques, deviations from the predetermined level were small and clinically acceptable for all techniques. Leakage following obturation was comparable in all groups.     

Apical sealing ability of 2 epoxy resin-based sealers used with root canal obturation techniques based on warm gutta-percha compared to cold lateral condensation.

OBJECTIVE: To evaluate the apical sealing ability of 2 epoxy resin-based root canal sealers used with 2 different warm gutta-percha obturation techniques and cold lateral condensation. METHOD AND MATERIALS: The root canals of 72 freshly extracted single-root incisors were prepared and randomly assigned to 6 experimental groups. Root canal fillings were performed using either cold lateral condensation, warm vertical condensation, or Thermafil obturators with EndoRez or AH Plus as sealer. After root canal filling, the teeth were stored in 5% methylene blue solution for 7 days. Linear dye penetration was measured in bisected specimens by a calibrated investigator using a light microscope. RESULTS: Statistical analysis revealed significantly higher penetration depths in groups where EndoRez was used (P < .05, Tukey test). Regarding the different obturation techniques, the least amount of dye penetration was observed for AH Plus and EndoRez when warm vertical condensation was used. CONCLUSION: The results of this study indicate that the apical sealing ability of EndoRez is not as effective as that of AH Plus. Thermafil obturators and warm vertical condensation achieved seals with low dye penetration depth. The use of these techniques might decrease the risk of apical leakage.     

The antimicrobial effect of apical box versus apical cone preparation using iodine potassium iodide as root canal dressing: A pilot study

Abstract

Purpose. The purpose was to study the reduction of intra-canal microflora in premolars with apical periodontitis instrumented with either apical box or apical cone preparation and to provide measurements of intervention effects to allow proper power calculation in future clinical trials. Methods. Twenty-four patients were centrally randomized to apical box preparation (size #60) or cone preparation (apical size #25). The groups were comparable regarding the presence of primary caries and type of coronal restoration. In the course of canal preparation each tooth was irrigated with 2.5% NaOCl (12 ml). Lastly, the canals were filled with 17% EDTA (2 × 30 s) and 5% iodine potassium iodide (IKI) for 10 min. The canals were sampled for micro-organisms on four occasions: before instrumentation, after instrumentation, after application of IKI dressing and at the beginning of the second appointment 1 week later. Between the treatment sessions, the root canals were sealed with IRM cement. In the laboratory, culture techniques were used to measure microbial growth, which was classified as: none, very sparse, sparse, moderate, heavy or very heavy. Results. Initially, microbes were recovered in 88% of the teeth. Growth was classified as none in 35% of the teeth after instrumentation and in 50% after the application of IKI. Irrespective of the time of sampling, no significant difference in microbial growth reduction was observed between the two types of apical preparation. Based on the 1-week post-sampling, a power calculation revealed that over 900 patients are needed to show a difference of 9% between the two protocols tested. Conclusions. Future trials should be conducted using stringent protocols and as multi-centre trials for reaching the required information size.