根尖倒充填术微渗漏的研究进展

根尖倒充填术扩大了保留牙齿的适应证的范围,提高了患者的生活质量,但是对决定手术能否成功的关键因素—根尖倒充填微渗漏的研究结果仍然不统一。本文从根尖切除方法、根尖切除斜度、根尖切除后术区处理、根尖倒充填材料等方面加以综述。     

根尖倒充填材料的研究进展

根尖倒充填术的目的是严密封闭根尖孔与根尖周组织的交通，预防根尖微渗漏，常用于非手术治疗失败，不能用常规方法进行根管治疔术且要尽量保留患牙的病例。由于大量材料已应用于根尖倒充填，本文对各种以往在临床和动物实验中常用的根尖倒充填材料作一简要综述。     

Nd：YAG激光照射对根尖倒充填术窝洞封闭性影响的初步研究

目的:探讨Nd:YAG激光照射对根尖倒充填术封闭性的影响.方法:将根管形态相近的52 颗牙齿(前牙35 颗,前磨牙17 颗)随机分成5 组,每组10 颗,其余2 颗为电镜观察标本备用牙.去除牙冠,进行常规根管充填后去除根尖2 mm,用高速球钻将截面预备成碟形洞面.除第1 组外,分别用Nd:YAG激光以不同的时间和不同的方式(涂墨水与不涂墨水)照射洞面,用玻璃离子倒充填后进行微渗漏实验.扫描电镜观察激光处理后窝洞表面结构的改变,分析激光改善窝洞密封性的可能机制.结果:Nd:YAG激光照射组微渗漏程度显著低于对照组(P<0.01),并且涂墨汁组的微渗漏比未涂墨汁组的微渗漏明显减少(P<0.01).激光照射20 s组微渗漏明显低于照射10 s组(P<0.01).结论:Nd:YAG激光照射倒充填窝洞可以增加玻璃离子倒充填窝洞的封闭性.     

Er,Cr:YSGG激光切割对牙根尖封闭效果影响的微渗漏研究

目的 :探讨Er,Cr:YSGG激光进行根尖切除、预备后对倒充填材料密合性的影响 ,为此激光在临床上的应用提供重要的理论及实验依据。方法 :将 32个新拔除的单根离体牙随机分成 4组。去除牙冠 ,常规根管充填。第 1组 ,不做任何处理 ,作为阳性对照组 ;第 2组 ,手机切割组 ,手机进行根尖切除、预备后 ,银汞合金倒充填 ;第 3组 ,激光照射组 ,2WEr,Cr:YSGG激光于无水条件下照射根尖区 6s;第 4组 ,激光切割组 ,4WEr,Cr:YSGG激光于喷水条件下进行根尖切除、预备后 ,银汞合金倒充填。采用微渗漏实验对此激光切割后的牙根尖封闭效果进行评估。结果 :与阳性对照组相比 ,激光照射组的染料微渗漏深度无显著改善 (P >0 .0 5 ) ;与手机切割组相比 ,激光切割组的染料微渗漏深度有所减少 ,但并无显著性差异 (P >0 .0 5 )。结论 :Er,Cr:YSGG激光进行根尖切除、预备与常规手机预备具有同样的根尖封闭效果 ,因此有望在根尖倒充填术中取代手机 ,应用于口腔临床。     

不同材料及根尖术式对根管封闭性的影响

目的:评价MTA、iRoot BP Plus两种根管充填材料在根管正充填与倒充填两种不同根尖术式下的根管封闭效果。方法::收集因牙周、正畸拔除并符合标准的下颌恒前磨牙40颗,根管预备后随机分为4个实验组(n=8)和2个对照组(n=4):A组(MTA正充填组)、B组(iRoot BP Plus正充填组)、C组(MTA倒充填组)、D组(iRoot BP Plus倒充填组)、M组(阳性对照组)、N组(阴性对照组)。使用印度墨汁染色技术,透明牙技术评价两种材料在根管正充填与倒充填两种不同根尖术式下的根管封闭效果。结果:各实验组根方均有不同深度的墨汁渗入,A、B组较C、D组微渗漏值稍大,但各组间差异无统计学意义(P>0.05)。结论:MTA、iRoot BP Plus在根管正充填与倒充填两种不同充填方式下能取得同样的根尖封闭效果。因此,对于部分特殊部位的根尖病变以及止血困难等行根尖倒预备、倒充填较困难的病例可以选择MTA或iRoot BP Plus正充填后再行根尖切除这一手术方式作为有效的替代方式。     

镓合金在根尖切除术中根尖倒充填的临床应用

目的:观察镓合金在根尖切除术中根尖倒充填的临床应用.方法:32个根管治疗后根尖周病灶未消退而施行根尖切除术的患牙,用镓合金进行根尖倒充填术,术后进行3、9、12、36个月随访观察.结果:32个患牙除2个因牙折拔除外,成功率达93.75%.结论:镓合金与骨组织界面结合紧密,对口腔黏膜及牙龈组织无刺激,无毒性,无过敏反应,是较理想的根尖倒充填材料.     

根管充填后根尖微渗漏的评估及预防方法

根管充填的作用在于封闭整个根管系统,封闭不严会造成根尖微渗漏导致治疗失败。根尖微渗漏是评价根管充填材料根尖封闭效能的常用指标,目前评估根尖微渗漏的主要方法包括:染色法、液体滤过(传输)法、电化学法、放射性同位素渗透法和细菌或内毒素渗透法等。Nd:YAG激光和Er:YAG激光照射后可有效预防根尖微渗漏。     

磨牙根尖切除术和倒充填术的临床疗效观察

目的观察根尖切除术和倒充填术在难治性磨牙牙髓病和根尖周病治疗中的临床疗效。方法选择41颗难治性牙髓病和根尖周病的磨牙,经常规根管治疗无效,进行根尖切除术和根尖倒充填术,术后随诊观察。结果本组41颗患牙,其中28颗手术治疗后无自觉症状且完全恢复功能,组织附着紧密。10颗患牙经治疗后咀嚼基本正常,瘘管消失,疼痛消失,根尖阴影缩小。临床成功率为92.68。结论根尖切除术和倒充填术在难治性磨牙牙髓病和根尖周病治疗中,具有满意的疗效。     

不同根尖倒充填材料临床疗效分析

目的：比较不同封闭性能的充填材料在根尖倒充填治疗中的临床疗效。方法：选择近2年因常规根管治疗无法治愈行根尖切除及根尖倒充填治疗的根尖周疾患病例69例;共72颗牙（其中上颌中切牙31颗、上颌侧切牙24颗、上颌尖牙17颗）根据选择的倒充填材料分为MTA治疗组（M组）、银汞合金治疗组（Y组）、银粉玻璃离子水门汀组（B组）,每组24颗牙,三组均肉眼下进行根尖切除、倒预备及根尖倒充治疗。术后随访24月,通过临床体征及影像学评判术后疗效,统计分析术后6月、12月、24个月临床治愈率及术后短期（1周内）局部炎症反应发生率。结果：术后2年M组临床治愈率高于Y组和B组（P〈0．05）,差异有统计学意义;Y组与B组之间有效率无明显差异（P〉0．05）;术后6个月治愈率M组与Y组、M组与B组间差异有统计学意义（P〈0．05）,Y组与B组差异无统计学意义（P〉0．05）;术后1周内M组肿痛发生率略少于Y组与B组,但经统计学处理差异无统计学意义（P〉0．05）。结论：以上三种不同根尖封闭性能的充填材料均能有效提高根尖倒充填治疗的临床效果,但MTA根尖封闭性能更好,根尖倒充填的临床治愈率更高。     

牙髓病及根尖周病

冠折年轻恒前牙活髓切断术后临床及X线研究；连续波热牙胶垂直充填术根尖微渗漏的研究；R-H糊剂超填对疗效的影响；根管治疗后冠部封闭材料的渗漏研究；手用ProTaper镍钛器械根管预备后不同充填方法的效果研究     

The effect of varnish and pit and fissure sealants on the sealing capacity of retrofilling techniques

Freshly extracted teeth with single canals were instrumented and filled with laterally condensed gutta-percha and sealer. After obturation, the tooth apices were treated with various retrograde techniques. The sealing ability of these techniques, namely laterally condensed gutta-percha, heat-sealed gutta-percha, and silver amalgam retrofilling, was compared on the basis of dye penetration. The apical foramen of the treated canals was then coated with different sealing materials--HelioSeal (light-activated sealant), Delton pit and fissure sealant (chemically activated sealant), and varnish--to examine their effect on the leakage resistance of these materials. Statistical analysis indicated that laterally condensed gutta-percha, as well as retrograde amalgam filling, produced a statistically significantly better seal than heat-sealed gutta-percha. Coating of the apical foramen with different sealing materials showed that HelioSeal had significantly improved the sealing capacity of all the materials tested at each time period. Delton pit and fissure sealant did not increase the sealing ability in the first week. However, this material has significantly improved the sealing ability after the first week. On the other hand, sealing of the apical foramen with varnish did not produce any significant change in the sealing capacity of the filling materials. Finally, dye penetration around all the filling and retrofilling materials, in the presence or absence of the apical seal, continued and increased with time. However, root canals sealed with Helioseal consistently showed the least amount of apical leakage of all the canals tested.     

Retrograde approaches in endodontic therapy.

The routine use of retrograde fillings during apical surgery, as well as the material of choice for that purpose, have been debated. A retrograde filling is placed so as to seal an infected root canal causing periapical pathosis. Therefore, retrograde root canal fillings should be performed routinely during apical surgery regardless of the apparent technical quality of the root canal obturation, unless orthograde endodontic treatment is performed in conjunction with surgery. When orthograde treatment is not performed, retrograde root canal filling enhances the prognosis of apical surgery. An array of potential retrograde filling materials have been extensively investigated in vitro and in vivo. Once that the biocompatibility of the materials is confirmed a clinical comparison, rather than in vitro sealability studies, is the most valid evaluation method. Some of the difficulties encountered in long term clinical studies in patients may be avoided in animal studies. The review of the relevant literature of the past decade suggests that amalgam used in conjunction with cavity varnish is the retrograde filling material of choice. It must be stressed, however, that retrograde filling is not comparable to debridement and obturation of the entire root canal. Therefore, when the only way to approach the root canal is from the apical direction, rather than placing an apical retrograde filling, a retrograde endodontic treatment of the entire canal should be preferred, if it is feasible.     

Retrograde approaches in endodontic therapy

Abstract The routine use of retrograde fillings during apical surgery, as well as the material of choice for that purpose, have been debated. A retrograde filling is placed so as to seal an infected root canal causing periapical pathosis. Therefore, retrograde root canal fillings should be performed routinely during apical surgery regardless of the apparent technical quality of the root canal obturation, unless orthograde endodontic treatment is performed in conjunction with surgery. When orthograde treatment is not performed in conjunction with surgery. When orthograde treatment is not performed, retrograde root canal filling enhances the prognosis of apical surgery. An array of potential retrograde filling materials have been extensively investigated in vitro and in vivo. Once that the biocompatibility of the materials is confirmed a clinical comparison, rather than in vitro sealability studies, is the most valid evaluation method. Some of the difficulties encountered in long term clinical studies in patients may be avoided in animal studies. The review of the relevant literature of the past decade suggests that amalgam used in conjunction with cavity varnish is the retrograde filling material of choice. It must be stressed, however, that retrograde filling is not comparable to debridement and obturation of the entire root canal. Therefore, when the only way to approach the root canal is from the apical direction, rather than placing an apical retrograde filling, a retrograde endodontic treatment of the entire canal should be preferred, if it is feasible.     

In vitro quantification of the apical sealing ability of retrograde amalgam fillings

Retrograde amalgam fillings were placed in 12 extracted human canines. The microleakage from the both directions (coronally and apically) was determined using pressurized fluid filtration at 90 min, 6 h, 1 day, 2 days, and 1,2,4, and 8 wk after amalgam filling. Leakage from either direction decreased markedly in the 90-min to 6-h interval after filling. At intervals between 1 day and 8 wk, only small changes in leakage were noted. After any time period, leakage from the coronal direction was greater than leakage from the apical direction. However, this difference was not statistically significant except at 90 min when the coronal leakage was significantly greater. This experimental system was shown to reliably measure microleakage in retrograde amalgam fillings.     

In vitro evaluation of the apical seal of two different retrograde filling materials

To determine whether the selection of retrograde filling material or the choice of instruments in root tip resection influences the seal of the retrograde root filling. Seventy‐two single‐rooted teeth were used. Root resection was performed using a Lindemann bone cutter, a Lindemann bone cutter with A‐shaped cutting design or a diamond‐coated bur. Retro‐cavities were prepared by piezo‐tips and filled with Super‐EBA or MTA. Teeth were made transparent and dye penetration was assessed. Teeth filled with MTA, irrespective of the resection instrument, showed no measurable dye penetration. All groups filled with Super‐EBA showed an apical leakage. There were no significant differences between the three groups filled with Super‐EBA (P = 0.09). The comparison of MTA versus Super‐EBA showed significant superiority in apical seal in favour of MTA (P < 0.0001). To use MTA as a retrograde filling material showed superior results in terms of the tightness of the apical seal as compared to Super‐EBA.     

Long-term durability of root-end sealing with 4-MEtA/MMA-TBB resin

The purpose of this study was to compare root-end sealing using 4-META/MMA-TBB resin with that using conventional retrograde root filling technique, and thereby determine if 4-META/MMA-TBB resin offers long-term prevention against dye leakage from the root canal of human teeth. Thirty-five teeth had the apical 2.5 mm of the root resected. In the Sealing (SB) group, 4-META/MMA-TBB resin was applied to the resected surface. In the Filling (Am and EBA) groups, a root-end cavity was prepared and retrofilled with high copper amalgam alloy or reinforced zinc oxide-eugenol cement. Root canals were filled with methylene blue dye solution. Then, dye leakage outside the root canal was measured for 50 weeks. The integrated amount of leakage in SB group was significantly lower than those in Am group (p < 0.05) and EBA group (p < 0.05). Therefore, it can be concluded that root-end sealing using 4-META/MMA-TBB resin resulted in better, long-term sealing than conventional retrograde root filling.     

Relationship of periapical lesion radiologic size, apical resection, and retrograde filling with the prognosis of periapical surgery.

PURPOSE: Periapical surgery eliminates the periradicular inflammatory tissue and seals the apical foramen. The present study relates the radiologic size of the periapical lesion, apical resection, and retrograde filling to the middle- and long-term success of periapical surgery. MATERIALS AND METHODS: In a prospective study, 235 patients and 333 teeth were subjected to ultrasound instrumentation and retrograde filling with silver amalgam. Radiographic measurements were made of the maximum and minimum diameters of 320 periapical lesions before surgery. In the 384 apicoectomized roots, calculations were made of the eliminated apical portion, and in 526 root canals the magnitude of retrograde filling was determined. The patients were subjected to a minimum follow-up period of 12 months, with a mean of 27.8 months (range 12 months to 10 years). RESULTS: Global evaluation showed a success rate of 73.9% after 12 months. The mean periapical area before surgery was 37 mm(2) (maximum diameter, 7.4 mm; minimum diameter, 5 mm). The mean apical resection was 6.48 mm(2) (height, 2.7 mm; base, 2.4 mm). The mean area of the retrograde cavities was 3.05 mm(2) (long side, 2.25 mm; short side, 1.1 mm). A positive correlation was observed between the dimensions of the lesion and apical resection with the treatment failure. None of the dimensions of the filling cavity was related to treatment failure. CONCLUSION: The prognosis of periapical surgery improves with decreasing periapical lesion size and lesser apical resection, and is not dependent on the magnitude of retrograde filling.     

A clinical study on treatment results of apicoectomy

In this study, the treatment results of apicoectomy with orthograde filling were compared with those of apicoectomy with retrograde gutta-percha filling and retrograde sponge gold filling. The long-term follow-up results of the teeth treated by apicoectomy are presented, and the possible prognostic factors are discussed. The healing process of the apical bone cavity was analyzed with standard X-ray techniques and image analysis system. One hundred nineteen teeth were apicoectomized with orthograde filling, 196 teeth with retrograde gutta-percha root filling and 42 teeth with sponge gold filling. There was no significant correlation between the treatment results and the sex or age of the patients, kinds of teeth, preoperative radiolucent areas, the number of operations or histopathological diagnosis of apical lesion. The success rate of apicoectomy with orthograde filling or apicoectomy with retrograde gutta-percha root filling was significantly higher than that with retrograde sponge gold filling. The filling materials and the operation method were considered to be the most important factors for a successful outcome. Bone reconstruction was found to start from the periphery of the bone cavity and the bone defect became gradually reduced in a star-like pattern. At 4 months after operation, in the successful cases, the area of bone cavity decreased 46-64% compared with before operation, but in the unsuccessful cases, the area did not change or increased 75-120%. Thus at 4 months after operation, it is possible to determine whether or not apicoectomy is successful.     

Effect of immediate dowel space preparation on the apical seal of endodontically filled teeth.

The purpose of this study was to investigate in vitro the effect of using hot endodonic pluggers for immediate dowel space preparation on the apical seal of endodontically treated teeth filled by a chloropercha technique. The results demonstrated that, when the coronal half of the root canal filling material was removed immediately after placement with pluggers, there was a loss of the apical seal and leakage in thirteen of twenty teeth. There was also leakage in thirteen of twenty teeth in which dowel spaces were not prepared. This study did not demonstrate a significant difference statistically in loss of apical seal and leakage between teeth prepared with and those without immediate dowel space preparations with pluggers using a chloropercha filling technique. Immediate preparation of the dowel spaces had no effect on the apical seal. The chloropercha technique by itself showed evidence of very high leakage when used to fill the root canal.     

A quantitative microleakage study on a new retrograde filling technique

An in vitro endodontic leakage model was used to compare the sealing ability of conventional retrograde amalgam fillings with a new retrograde filling technique by measuring dye leakage quantitatively. The new technique consisted of retrograde preparation of the root canal using the Endocursor, an endodontic handpiece. The canal was then filled with sealer and injection-moulded gutta-percha, using either the Hygenic Ultrafil system or the Unitek Obtura method. In both cases the gutta-percha was vertically condensed and subsequently cold-burnished. The two experimental groups and the amalgam group each consisted of 20 extracted human canine teeth and lower premolars. The results were analysed statistically by ANOVA and a Student-Newman-Keuls multiple comparison test. After 1 week at 37 degrees C, very little leakage was observed in the amalgam and gutta-percha groups. After a second week, during which leakage was enhanced by gas pressure, leakage in the amalgam group was significantly greater than that in the gutta-percha groups (P less than 0.01). There were no significant differences between the two experimental gutta-percha groups. It is concluded that the new retrograde filling technique causes less leakage than the conventional amalgam retrograde filling technique in an in vitro model.