Healing of apical periodontitis after endodontic treatment using three different root canal sealers

Abstract In this study 3 commonly used sealers were evaluated. The materials tested were Proco-Sol, a zinc oxide-eugenol-based sealer, AH26, an epoxy resin, and Klorperka NØ, a resin-gutta-percha-chloroform sealer. The healing of periapical lesions was followed for a period of 3 years. While the response to Kloroperka NØ seemed slightly inferior to the 2 others, no statistically significant differences among the groups could be demonstrated.     

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.     

乳磨牙根管口部形态的增龄变化研究

目的 研究下颌乳磨牙根管口部形态的增龄变化。方法 选取3-8岁患儿86颗诊断为牙髓炎症的下颌乳磨牙，拍摄X线牙片，失活，揭髓顶，拔髓，清洗根管后，取根管口部形态印像，制作树脂模型，在牙轴与髓室底最高点相交处于方0.5mm-1.0mm处制作两枚切片，用计算机进行分析测量，按年龄分成3组进行研究。结果 下颌第一乳磨牙近中根管口部宽度明显大于过错中根管，第二乳磨牙则相反，X线牙片测量值大于树脂切片测量值，根管口部长度测量显示第一乳磨牙近中根管口小于远中根管口，而第二乳磨牙近远中根管长度近似，下颌第一、二乳磨牙近中根管口面积都小于远中根管，第一、二乳磨牙髓室底厚度都有随年龄增长而增厚趋势，结论 本研究结果对乳牙牙髓和根管治疗，特别对活髓切断术器械选择，具有重要参考价值。     

下颌第二磨牙根管系统的临床诊断和治疗

目的:探讨下颌第二磨牙根管系统的特征及临床诊断和治疗方法。方法:选取患牙髓炎或根尖周炎的下颌第二磨牙 127个,拍摄术前X线片,探查根管,确定根管形态和类型;采用机用镍钛器械Hero642预备根管,热牙胶垂直加压技术充填根管。根据治疗前后的X线片评价根管预备和充填效果。结果:下颌第二磨牙独立 3个根管的发生率为 54. 3%, 独立 2个根管和单一根管的发生率为 11. 0%和 3. 1%,C形根管的发生率为 31. 5%,以Ⅰ、Ⅱ型居多。所有患牙均无根管内并发症发生,治疗效果佳。结论:下颌第二磨牙根管系统以独立的 3个根管为主,其次为C形根管,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热牙胶垂直加压技术充填根管可获得良好的治疗效果。     

双侧下颌第一恒磨牙融合根伴C形根管1例

下颌第一恒磨牙的牙根通常为2~3根伴2~4个根管,融合根伴C形根管较罕见。本文报道1例双侧均为融合根伴C型根管的下颌第一恒磨牙患者。     

677个下颌第一磨牙牙根和根管数目分析

目的：调查下颌第一磨牙的牙根和根管数目，以期为临床治疗提供指导。方法：选取需治疗的下颌第一磨牙，采用X线片观察牙根数目和扩大针探查根管数目。结果：在677个下颌第一磨牙中，2个牙根的发生率为84．9％（575／677），为近中根和远中根，3个牙根的发生率为15．1％（102／677），为近中根、远中根、远中舌根；2个根管的发生率为0．1％（1／677），为近中远中各1个根管，3个根管的发生率为74．7％（506／677），为近中2根管，远中1根管，4个根管的发生率为25．1％（170／677），为近中2根管，远中2根管。2个牙根4根管的发生率是11．8％，3个牙根4根管的发生率是100％。结论：远中舌侧牙根（RE）的出现增加了4个根管的发生率；在根管治疗术时对牙根和根管数目的仔细检查非常重要。     

METAPEX糊剂预防乳牙一次性根管治疗术后急诊的效果评价

目的:评价METAPEX糊剂-氢氧化钙碘仿糊剂用于乳牙一次性根管治疗术后急诊的效果.方法:选择178例238颗需要进行根管治疗的乳磨牙,随机分为2组,实验组采用METAPEX糊剂一次性根管充填,对照组采用氧化锌丁香油糊剂治疗.采用SPSS14.0软件包对数据进行X2检验.结果:METAPEX糊剂组急症发生率明显低于氧化锌丁香油糊剂组,具有显著性差异.结论:METAPEX糊剂能有效降低乳牙一次性根管治疗术后急诊的发生.     

Radiographic follow-up of periapical status after endodontic treatment of teeth with and without apical periodontitis

Objectives

The aim was to assess objectively the rate of changes in periapical status after endodontic treatment in relation to preoperative radiographic status (Periapical Index Score, PAI) and to tooth type.

Material and methods

Radiographic data from a total of 1,410 teeth in seven prospective clinical studies was pooled. The periapical status was evaluated blindly using the PAI scoring system. The longest follow-up period was 4 years; intervals between controls varied from 3 months to 1 year.

Results

Teeth with preoperative PAI score 1 maintained excellent periapical health throughout. Teeth with preoperative PAI score 2 showed some impairment in health over the first 6 months, but improved to approach 95 % healthy teeth at 2 years of observation. Teeth with PAI 3–5 at the start showed significant improvement at 3 months; 27 % were considered healthy (PAI 1 or 2) increasing to 41 % after 1 year. Improvement of periapical status was slower in PAI groups 4 and 5 compared with PAI 3 during the first year. After 2 years, improvement continued similarly in all preoperative PAI 3–5 groups of teeth. Upper lateral incisors showed the poorest healing rate.

Conclusions

Healing of pre-existing periapical lesions is most pronounced from 3 months to 2 years. Teeth with initially healthy periapical structures predictably maintain good periapical health. Maxillary teeth, especially lateral incisors, showed poorer healing rates than mandibular teeth.

Clinical relevance

Radiographic healing rates may vary among tooth groups within the dentition. Periapically healthy teeth that are root filled may not need postoperative controls.     

上颌第一磨牙根管系统的研究

目的 观察上颌第一磨牙的根管系统。方法 制备50个上颌第一磨牙透明牙标本,显露根管系统的空间构型,在体视显微镜下观察并记录根管系统的形态,结合应用加以统计。结果 ①上颌第一磨牙近中颊根单根管率为66%,其中Ⅰ型占38%,双根管率为34%,远中颊根Ⅰ型占74%,腭根Ⅰ型占94%。②根管侧支、根尖分歧、根尖分叉多见于近颊根,在近颊根的发生率为40%, 远颊根的发生率为24%,腭根的发生率为6%,发生部位多见于根尖1/3。结论 上颌第一磨牙近颊根的根管系统最为复杂,根管变异较远颊根多,腭根变异最少。     

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.     

Gram-positive rods prevailing in teeth with apical periodontitis undergoing root canal treatment

AIMS: To identify Gram-positive rods from root canals of teeth with apical periodontitis and to examine their associations with other species. METHODOLOGY: Consecutive root canal samples (RCSs) from 139 teeth undergoing root canal treatment were analyzed prospectively for cultivable microbes. Gram-positive rods in the first RCS submitted after chemo-mechanical preparation were categorised to genus level by selective media and gas-liquid chromatography (GLC), and identified to species level by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). Associations between organisms were measured by odds ratios (OR). RESULTS: In the first samples submitted a total of 158 Gram-positive rods, 115 Gram-positive cocci, 26 Gram-negative rods and 9 Gram-negative cocci, were identified. At genus levels Gram-positive rods were classified into: Lactobacillus spp. (38%), Olsenella spp. (18%), Propionibacterium spp. (13%), Actinomyces spp. (12%), Bifidobacterium spp. (13%) and Eubacterium spp. (6%). The most frequent species were Olsenella uli, Lactobacillus paracasei and Propionibacterium propionicum. In subsequent samples taken during treatment, Gram-positive rods were also identified, although the number of strains was considerably reduced. Positive associations were observed between members of the genus lactobacilli and Gram-positive cocci (OR>2). CONCLUSIONS: Olsenella uli and Lactobacillus spp. predominated over other Gram-positive rods. A possible association exists between Lactobacillus spp. and Gram-positive cocci in root canals of teeth with apical periodontitis receiving treatment.     

Study of root canal accessibility in human primary molars

The aim of the present study was to provide a general scheme for pulpectomy of primary molars that may be useful for decision-making about negotiation of root canals and selection of appropriate instruments. A total of 160 vital primary molars in 85 patients (40 males, 45 females) aged 4-6 years were selected. After taking primary radiographs, local anesthesia was induced, and the teeth were isolated using a rubber dam. Canal accessibility index (CAI) and tooth accessibility index (TAI) were calculated according to initial file size. Mandibular first molars had either three canals (79.2%) or four canals (20.8%), and all second molars had four canals. Maxillary first molars had three canals and second molars had either three canals (70.9%) or four canals (29.1%). Lower accessibility of the mandibular first molar distobuccal root accounted for the lower accessibility of these teeth in comparison with mandibular second molars. While three-canal maxillary second molars were more accessible due to the lower accessibility of the distobuccal canal of the maxillary first molar, poor accessibility of the distal canal in four-canal second molars was responsible for the difficult accessibility of these teeth. In conclusion, it seems that the accessibility of a single canal in each tooth determines the difficulty of accessibility for any given tooth. Moreover, while primary second molars are more accessible than first molars, all of them are negotiable.     

Success rate of root canal treatment in primary molars

OBJECTIVES: The purpose of the present retrospective large-scale study is to evaluate rate of success of root canal treatments in primary infected molars using Endoflas F.S as a filling material. METHODS: The study material consisted of 382 records of root canal treated primary molars of which 174 teeth with high quality radiographs and sufficient data comprised the 'study group'. The technique for root canal treatment in one visit is described. Treatment was considered success if clinically the tooth was asymptomatic and radiographs showed decrease or no change in pre-existing pathologic radiolucent defects. RESULTS: In the total pulpectomy group there was a statistically significant difference between mandibular teeth presented with a periapical lesion prior to the treatment compared to maxillary teeth. This difference was not significant in the study group. Decrease in post treatment radicular radiographic defects was statistically significant more in the maxilla compared to the mandible. The success rate of teeth restored with a permanent restoration (stainless steel crown or amalgam filling) was statistically significant higher than those teeth left with a temporary filling. There was no statistically significant difference between success rate and the extent of root canal filling material. Rate of success was not statistically different depending on pre-existing radiolucent area prior to RCT. CONCLUSIONS: Endoflas F.S. can be used as an alternative root canal filling material for primary teeth. One condition for success is the prevention of microleakage. A permanent restoration should be placed as soon as possible after clinical signs and symptoms of inflammation are eliminated.     

Morphometric study of the apical anatomy of C-shaped root canal systems in mandibular second molars

AIM: To investigate the apical anatomy of C-shaped canal systems in mandibular second molars by micro-computerized tomography (microCT) and stereomicroscopy. METHODOLOGY: Forty-four permanent mandibular second molars with a C-shaped root canal systems from a native Chinese population were scanned at 100 microm intervals by microCT at a resolution of 30 x 30 microm. The apical 5 mm of each tooth was reconstructed three-dimensionally for visualization and classification of the canal configuration using Vertucci's criteria. The main and auxiliary (accessory) foramina were examined under a stereomicroscope. RESULTS: Type IV and VIII canal configurations were most often found in the apical 5 mm of these canal systems. The prevalence of accessory canals, lateral canals, inter-canal communications and apical delta were 41%, 25%, 27% and 11%, respectively. Approximately 80% of C-shaped canals had 1-3 apical foramina; the prevalence of accessory foramina was about 48%. The mean distance between the main foramen and the anatomic root apex was 0.84 mm, and that between the accessory foramen and the apex was 1.61 mm. The mean (shortest and longest) diameters of major and accessory foramina were 0.19 - 0.32 mm and 0.07 - 0.10 mm, with a mean form factor of 0.73 and 0.82, respectively. CONCLUSION: The apical anatomy of C-shaped root canal systems in mandibular second molars is extremely complex with many anatomical variations.     

Microbial analysis of endodontic infections in teeth with post-treatment apical periodontitis before and after medication

This study aimed to determine the intraradicular microbiota of previously root canal-treated teeth with apical periodontitis and to investigate the antibacterial effectiveness of different intracanal medicaments. Sixteen patients with post-treatment apical periodontitis were allocated into two groups according to the intracanal medicament used: calcium hydroxide (CH) and 2% chlorhexidine gluconate gel (CHX) group. Total bacterial loads, as well as the amount of Enterococcus faecalis (E. faecalis) were determined before (S1) and after (S2) chemomechanical preparation and finally, after intracanal medication (S3) by means of ddPCR. The unpaired t test was used to compare parametric. S3-total bacteria copy number of the CH group was lower than the CHX group (p < 0.05). There was no statistical difference between the CHX- and the CH groups in terms of E.faecalis copy number (p > 0.05). But in terms of total bacteria, CH is better than CHX. Consequently, CH can be used to optimise the antibacterial efficiency of chemomechanical preparation in previously root canal-treated teeth with apical periodontitis.