Calculus-like deposit at apex of tooth with refractory apical periodontitis

Abstract— It is generally accepted that bacteria in or outside the root canal are the reason for apical periodontitis and endodontic failures. This case report presents a 60-year-old woman with a periapical lesion and a fistulous tract which did not respond to conventional root canal treatment. During periapical surgery, granulomatous tissue was removed and a calculus-like deposit was observed on the root surface. A radicular cyst was diagnosed. Nine months after this calculus-like deposit had been removed and the cyst enucleated, complete recovery of the bone had occurred. It is suggested that the presence of the calculus-like deposit at the apex of the tooth or its effects may in part have delayed the healing of the periapical inflammation in spite of apparently adequate endodontic treatment.     

Surgical management of a lateral lesion refractory to root canal retreatment caused by an extraradicular calculus. A case report

This article describes the management of a root canal-treated maxillary central incisor displaying a radiographic lateral radiolucency and a sinus tract that persisted irrespective of root canal retreatment following high standards. Endodontic microsurgery was indicated and curettage of the pathologic tissue revealed a calculus-like material attached to the outer root surface around the exit of a large lateral canal. A non-conventional approach was chosen: No root-end resection was conducted. Instead, the calculus was removed and the apical surface was scaled and smoothed, conserving the apical structure. Retrocavities were prepared in both lateral and apical foramens and filled with a bioceramic material. Follow-up examination showed optimal soft tissue healing. One-year follow-up of radiographs revealed healing of the lateral lesion. The lesion was diagnosed as a cyst, with an infected lumen. An exuberant calculus-like material attached to the external root surface was the most likely cause of the recalcitrant lateral periradicular lesion.     

Post-treatment apical periodontitis associated with a missed root canal in a maxillary lateral incisor with two roots: A case report

Missed canals can be a common cause of persistent intraradicular infection and post-treatment apical periodontitis. This article reports on a rare case of a maxillary lateral incisor with two roots exhibiting symptomatic post-treatment apical periodontitis regardless of a radiographically adequate root canal treatment. The second root, which was only revealed by cone-beam computed tomography, had passed unnoticed during the first treatment, and its missed canal was the most likely cause of symptoms and treatment failure. Reintervention including the proper management of the extra root canal and retreatment of the main canal resulted in the resolution of symptoms and periradicular tissue healing. This case report reinforces the need for three-dimensional radiographic diagnosis to search for the cause of post-treatment disease and guide the decision-making process for proper management.     

On the causes of persistent apical periodontitis: a review

Apical periodontitis is a chronic inflammatory disorder of periradicular tissues caused by aetiological agents of endodontic origin. Persistent apical periodontitis occurs when root canal treatment of apical periodontitis has not adequately eliminated intraradicular infection. Problems that lead to persistent apical periodontitis include: inadequate aseptic control, poor access cavity design, missed canals, inadequate instrumentation, debridement and leaking temporary or permanent restorations. Even when the most stringent procedures are followed, apical periodontitis may still persist as asymptomatic radiolucencies, because of the complexity of the root canal system formed by the main and accessory canals, their ramifications and anastomoses where residual infection can persist. Further, there are extraradicular factors -- located within the inflamed periapical tissue -- that can interfere with post-treatment healing of apical periodontitis. The causes of apical periodontitis persisting after root canal treatment have not been well characterized. During the 1990s, a series of investigations have shown that there are six biological factors that lead to asymptomatic radiolucencies persisting after root canal treatment. These are: (i) intraradicular infection persisting in the complex apical root canal system; (ii) extraradicular infection, generally in the form of periapical actinomycosis; (iii) extruded root canal filling or other exogenous materials that cause a foreign body reaction; (iv) accumulation of endogenous cholesterol crystals that irritate periapical tissues; (v) true cystic lesions, and (vi) scar tissue healing of the lesion. This article provides a comprehensive overview of the causative factors of non-resolving periapical lesions that are seen as asymptomatic radiolucencies post-treatment.     

Vitapex治疗成年患者根尖发育不全伴窦型慢性根尖炎的临床研究

目的观察Vitapex治疗成年患者根尖发育不全伴窦型慢性根尖周炎患牙的临床疗效。方法选择成年患者根尖发育不全并发窦型慢性根尖周炎患牙32颗,用Vitapex糊剂行根尖诱导术,定期复查,在确认根尖有硬组织形成,行永久性充填。结果根尖发育完成5例,占15.6%;根尖形成钙化桥24例,占75%;失败3例,占9.4%。总有效率90.6%。结论Vi-tapex治疗成年患者根尖未完全发育伴窦型慢性根尖周炎患牙有良好的临床疗效,值得临床推广。     

A 20-year follow-up study of endodontic variables and apical status in a Swedish population

AIM: To re-examine a population after 20 years and evaluate changes in prevalence of endodontic treatment and apical periodontitis, as well as the technical quality of root fillings. METHODOLOGY: One hundred and fifteen out of an original 200 patients living in the northern part of Sweden were re-examined with a full mouth radiographic survey after 20 years. Frequencies of root canal treated teeth, apical periodontitis and quality parameters of root fillings were registered. RESULTS: The frequency of root canal treated teeth increased significantly (P < 0.05) from 13.9% at the first investigation to 17.7% after 20 years. There was also a statistically significant increase (P < 0.05) in teeth with apical periodontitis from 3.3% to 6.8%. Apical periodontitis both in connection with root canal treated teeth and teeth without endodontic treatment, had increased during the follow-up period. Even though the quality of the root fillings had improved, there was no corresponding improvement of the apical status in teeth with root fillings. CONCLUSIONS: There is still a great need for endodontic treatment in the Swedish population, and no improvement in apical health was found during this 20-year follow up.     

Metapex糊剂治疗乳牙有窦型慢性根尖周炎的疗效观察

目的：对比Metapex糊剂与氧化锌碘仿糊剂在作为乳牙根充材料时的近期与远期效果。方法：选取2011年3月至2013年7月就诊于我院儿童口腔科且明确诊断为有窦型慢性根尖周炎的97例（108颗乳磨牙）患儿,将其随机分为实验组与对照组,实验组55颗患牙用Metapex糊剂进行根管充填,对照组53颗乳磨牙用氧化锌碘仿糊剂根充。对比2周、1年和2年后疗效,并进行分析。结果：2周成功率实验组显著高于对照组（P<0.05）,1年成功率无显著差异（P>0.05),2年成功率实验组优于对照组（P<0.05）。结论：Metapex糊剂治疗乳牙有窦型慢性根尖周炎疗效较好,是理想的根充材料。     

一次性和多次性根管治疗应用于根尖周炎的临床评价

目的评价根管治疗一次法和多次法对无症状根尖周炎疗效的影响,探讨一次性根管治疗的适应症。方法选取无症状根尖周炎的患牙160颗,分层随机法分为两组,分别采用一次法和多次法完成根管治疗。所有患牙均使用镍钛机动根管器械预备,牙胶冷侧方加压法充填根管。比较两组术后疼痛发生情况,根据患者主观症状、临床表现和术前术后X线片评价疗效。结果一次法和多次法在术后疼痛、根管治疗效的差异上没有统计学意义。结论一次性根管治疗应用于无症状根尖周炎的患牙是可行的,但要注意控制适应症。     

年轻恒前牙感染根管内血管再生的动物实验研究

目的通过建立根尖周炎模型观察年轻恒前牙根管内血管再生的组织学状况。方法选择4个半月龄杂种犬1只,建立上颌未发育完成的恒前牙根尖周炎模型,将6颗上颌恒前牙随机分组,对照组3颗采用根尖诱导成形术,实验组3颗采用根管内血管再生术。将术后1、4、8周的X线片分别与术前X线片进行对比,观察牙根继续发育及根尖炎症的愈合情况。术后8周处死动物,利用苏木精-伊红（HE）染色观察根尖闭合情况及根管内容物的构成。结果X线观察,术后1、4周,2组牙根的根尖孔大小及根尖透射区范围未见明显改变。术后8周,实验组根尖透射区范围缩窄较明显,并出现根尖孔缩窄的趋势,但管壁厚度无明显变化;而对照组根尖透射区变化不一。组织学检查,实验组管腔内可见肉芽组织,其中包含有大量的不规则的类牙本质、类牙骨质和类骨质样钙化物,钙化物以根尖部和管腔内侧壁尤为明显。对照组管腔未见软组织,根尖部有少量的硬组织沉积。结论血管再生术可促使年轻无髓恒前牙的慢性根尖周炎症消退,根管内再生的肉芽组织中有硬组织沉积。     

iRoot SP一次性根管治疗前牙窦道型慢性根尖周炎疗效观察

目的:观察iRoot SP一次性根管治疗前牙窦道型慢性根尖周炎的临床疗效.方法:纳入240 例前牙窦道型慢性根尖周炎患者,随机分成2 组(n=120),在Nd:YAG激光消毒下,进行一次性根管充填:观察组采用iRoot SP以热牙胶连续波垂直加压技术充填根管,对照组采用AH-plus糊剂以热牙胶连续波垂直加压技术充填根管,观察术后48 h疼痛发生情况、术后10 d窦道愈合情况及1 年后的疗效.结果:术后48 h观察组和对照组疼痛发生率分别为7.14%和15.0%(P=0.038);术后10 d,观察组和对照组窦道愈合情况有效率分别为95.8%和88.3%(P=0.031);术后1 年复诊,2 组疗效成功率分别为98.3%和94.8%(P>0.05).结论:iRoot SP和AH-plus糊剂在一次性根管治疗前牙窦道型慢性根尖周炎中均取得良好疗效,但iRoot SP术后反应发生率低,窦道愈合快.     

Investigation of the effect of the coronal restoration quality on the composition of the root canal microflora in teeth with apical periodontitis by means of T-RFLP analysis

AIM: To investigate the effect of the radiographic and clinical quality of coronal restorations on the composition of the root canal flora of teeth with necrotic pulps and teeth with root fillings associated with apical periodontitis. METHODOLOGY: Twenty-eight necrotic pulps and 35 root filled canals with signs of apical periodontitis were studied. Both the coronal filling (presence of radiographically or clinically deficient margins and/or secondary caries) and the root filling (homogeneity and length) were scored. Bacterial root canal samples were taken with sterile paper points under rubber dam and using measures to prevent contamination. A DNA-based nonculture bacterial identification technique was used, namely terminal restriction fragment length polymorphism (T-RFLP) analysis. RESULTS: Twelve samples were negative for bacterial DNA. A total of 33 different terminal restriction fragments (TRFs) were detected. The Fusobacterium nucleatum/Streptococcus mitis group was the most frequently encountered TRF. The mean number of TRFs per necrotic pulp was 6.2 and 5.8 for the groups with acceptable and unacceptable coronal restorations, respectively. This difference was not significant. In the root filled group, these values (respectively, 5.2 and 8.6) were statistically significantly different (P < 0.05). The following parameters in root filled teeth had no significant influence on the mean numbers of TRFs detected: the length and homogeneity of the root filling and the type of tooth (anterior-premolar-molar). CONCLUSION: T-RFLP allowed the rapid assessment of bacterial biodiversity in root canal samples. The technique revealed the presence of bacteria that have rarely been described in the root canals of teeth with apical periodontitis. Biodiversity in the root filled group was high, as compared with culture-dependent studies where monoinfections were more frequently reported. Only in root filled teeth did defective coronal restorations have a statistically significant influence on the mean numbers of detected TRFs per sample.     

Bacteria recovered from teeth with apical periodontitis after antimicrobial endodontic treatment

Chávez de Paz LE, Dahlén G, Molander A, Möller Å, Bergenholtz G . Bacteria recovered from teeth with apical periodontitis after antimicrobial endodontic treatment. International Endodontic Journal, 36 , 500–508, 2003. Aim To determine whether there is a pattern for certain bacteria to remain after chemo‐mechanical treatment of root canals in teeth with apical periodontitis. Methodology Consecutive root‐canal samples of 200 teeth receiving root‐canal treatment, referred from general practitioners and endodontic specialists for analyses of cultivable microbes, were studied prospectively. To be included, samples had to be taken at a treatment session subsequent to the one at which endodontic therapy was initiated. All samples were from teeth that either presented with clinical or radiographic evidence of apical periodontitis or both. Bacteriological findings were linked to clinical and radiographic parameters including status of the root canal prior to treatment, namely, vital pulp, necrotic pulp or root filled. Results A total of 248 strains were isolated from 107 teeth giving bacterial growth. Gram‐positives predominated (85%). Lactobacillus spp. (22%), nonmutans streptococci (18%), and Enterococcus spp. (12%) were the most common isolates. Gram‐negative anaerobes were relatively sporadic. Large radiographic bone lesions, persistent pain and use of intracanal calcium hydroxide dressing correlated with bacterial presence (P < 0.05). Conclusions Once established, nonmutans streptococci, enterococci and lactobacilli appear to survive commonly following root‐canal treatment of teeth with clinical and radiographical signs of apical periodontitis.     

未经治疗和根管治疗失败的慢性根尖周炎的细菌学研究

目的:比较未经治疗和根管治疗失败的慢性根尖周炎患牙根管内的感染状态并分析临床表征与特殊细菌之间的关系.方法:收集临床诊断为慢性根尖周炎的病例90 例,包括未治疗患牙和根管治疗失败患牙各45 例,根据临床症状分为疼痛组、窦道组和无症状组.详细记录患牙的临床表征并拍摄X线片.经根管内取样、接种、培养后检测根管内的细菌种类并...     

Scanning electron microscopic study of the apical dentine surfaces lased with Nd: YAG laser following apicectomy and retrofill

The purpose of this investigation was to study the effects of a Nd:YAG laser on the cut surface of teeth using scanning electron microscopy (SEM). Eighteen single-rooted teeth were cleaned, shaped, and obturated with gutta-percha and root canal sealer. The apical 3 mm of each tooth were resected with a diamond fissure bur, and the teeth were randomly divided into two groups of nine teeth each. The resected surface of each root in one group was lased twice. The duration of lasing and the number of pulses were recorded for each tooth. The teeth were air dried, mounted on stubs, sputter-coated with gold-palladium and examined under SEM. Application of the Nd:YAG laser caused melting of apical dentine surfaces. The melted material resembled the appearance of glazed interconnected droplets. Resolidification and recrystalization of the melted areas appeared to be incomplete and discontinuous. Some areas between the glazed regions appeared similar to those of non-lased apical dentine resected root surfaces.     

Effects of extensive apical reaming and calcium hydroxide dressing on bacterial infection during treatment of apical periodontitis: a pilot study

An apical dentine sampling technique was applied in order to monitor the bacteriology of the pulp canal and radicular dentine before and during treatment of teeth with chronic apical periodontitis. Twenty-three teeth with a radiographic diagnosis of apical periodontitis were studied. They were subjected to a standardized two-appointment treatment regimen of extensive apical reaming in the absence of antimicrobial agents and 1-week dressing with calcium hydroxide. Bacteriological samples were taken from the root canal at the start, and apical dentine samples at the end, of each sitting. Provision was made to allow growth of anaerobic bacteria. All root canals but one showed growth at the start of treatment. Dentine samples were positive in 14 of the 23 teeth at the end of the first appointment. Eight of the 23 canals had detectable growth from the canal at the start of the second appointment, but in sufficient numbers for quantification in only one root canal. The subsequent dentine samples were otherwise negative at the second appointment. There was a tendency for teeth causing symptoms to harbour more bacteria than symptomless teeth.     

Persistent apical periodontitis associated with a calcifying odontogenic cyst

Aim  To report a case of calcifying odontogenic cyst (COC) that was suggestive of apical periodontitis adjacent to the roots of the maxillary incisor teeth.
Summary  Tooth 21 presented with clinical and radiographic signs of secondary infection, a post within the root canal and substantial internal tooth destruction; it was scheduled for endodontic surgery. Teeth 12 and 22 were root filled following the placement of a calcium hydroxide intracanal dressing for 21 days. Three attempts at root canal disinfection in tooth 11 were unsuccessful, and a persistent purulent drainage precluded completion of root canal treatment. Surgical enucleation of the periapical lesion was undertaken and the tissues submitted for histopathological examination. A diagnosis of COC was established based on the microscopic analysis. COC is an unusual benign lesion that represents 2% of all odontogenic lesions. Depending on the stage of development, it can mimic a large lesion associated with apical periodontitis and should therefore be considered in the differential diagnosis. In the case of COC, the definitive diagnosis can only be made with histopathological analysis.
Key learning points  • Persistent apical periodontitis may be of nonendodontic origin.
• Histological examination is essential to establish the cause of persistent apical periodontitis.
• Calcifying odontogenic cyst can mimic apical periodontitis.     

Influence of infection at the time of root filling on the outcome of endodontic treatment of teeth with apical periodontitis

This study investigated the role of infection on the prognosis of endodontic therapy by following-up teeth that had had their canals cleaned and obturated during a single appointment. The root canals of 55 single-rooted teeth with apical periodontitis were thoroughly instrumented and irrigated with sodium hypochlorite solution. Using advanced anaerobic bacteriological techniques, post-instrumentation samples were taken and the teeth were then root-filled during the same appointment. All teeth were initially infected; after instrumentation low numbers of bacteria were detected in 22 of 55 root canals. Periapical healing was followed-up for 5 years. Complete periapical healing occurred in 94% of cases that yielded a negative culture. Where the samples were positive prior to root filling, the success rate of treatment was just 68%— a statistically significant difference. Further investigation of three failures revealed the presence of Actinomyces species in each case; no other specific bacteria were implicated in failure cases. These findings emphasize the importance of completely eliminating bacteria from the root canal system before obturation. This objective cannot be reliably achieved in a one-visit treatment because it is not possible to eradicate all infection from the root canal without the support of an inter-appointment antimicrobial dressing.     

Root canal treatment of an immature dens invaginatus with apical periodontitis: a case report

The purpose of this paper was to describe the case of an 11-year-old patient who presented a dens invaginatus, detected in the permanent maxillary left lateral incisor, with an immature open apex and extensive apical periodontitis and sinus tract. The mineralized invaginated barrier was removed, and a nonsurgical root canal treatment was performed using both calcium hydroxide as a root canal dressing to stimulate apexification and a mineral trioxide aggregate (MTA) plug to permit root canal filling. After a 14-month period of root canal dressing changes, no evidence of apical periodontitis was observed, and the MTA plug was placed in the root canal's apical portion. The root canal filling was performed using the thermoplasticized gutta-percha technique. At the 12-month follow-up, complete radiographic periapical healing, characterized by bone formation in the area around the tooth apex, and no clinical or radiographic evidence of refractory apical periodontitis were detected.     

Vitapex治疗成年患者根尖孔闭合不全并发慢性根尖周炎的疗效观察

目的：观察Vitapex对成年患者根尖孔闭合不全并发慢性根尖周炎患牙的临床疗效.方法：选择成年患者根尖孔发育不全并发慢性根尖周炎患牙36例,完成根管预备、消毒后,用氢氧化钙类糊剂Vitapex行根尖诱导术.经随访1～3a,在确认根尖有硬组织形成时,行注射式热牙胶根管充填,术后定期复查.结果：根尖发育完成者7例,占19.4%;根尖处有钙化桥形成者27例,占75%;失败2例,占5.6%.总有效率为94.4%,平均治疗周期为13.0周.结论：Vitapex对成年患者根尖孔发育不全并发慢性根尖周炎的患牙具有良好的临床疗效,值得临床推广应用.     

Influence of root canal dressings and sealers on repair of apical periodontitis after endodontic treatment

OBJECTIVE: The objective of this study was to evaluate the histopathologic response of periapical tissues after root canal treatment of necrotic dog teeth with chronic apical periodontitis by using 2 calcium hydroxide-based root canal dressings and 2 root canal sealers. STUDY DESIGN: Seventy-eight root canals were instrumented by using 5.25% sodium hypochlorite as the irrigating solution, after which a calcium hydroxide paste (Calen/PMCC or Calasept) was placed for 30 days as a dressing. The root canals were then filled by using cold lateral gutta-percha condensation and an endodontic sealer (Sealapex or AH Plus). After 360 days, the animals were killed by anesthetic overdose; then, the teeth were histologically prepared, sectioned, and stained with hematoxylin and eosin for optical microscopic analysis of apical and periapical tissue repair. RESULTS: Statistical analysis showed that the poorest histopathologic results were observed in the Calasept/AH Plus group and that the Sealapex sealer overall resulted in better apical repair than the AH Plus sealer. The histopathologic results of Calen/PMCC paste with both AH Plus and Sealapex and Calasept paste with only Sealapex were statistically similar but were different from the results of Calasept with AH Plus. CONCLUSIONS: The results of this study in the dog showed differences in apical and periapical tissue repair of teeth with chronic apical periodontitis by using 2 calcium hydroxide root canal dressings and 2 sealers. More research is necessary to determine the best combination of dressings and sealers.