Subtotal vital pulp extirpation using different medical preparations (experimental morphological research)

Pulp stump and periapical tissue reaction to root canal filling with material containing calcium hydroxide and potassium nitrate after subtotal vital extirpation of the pulp was studied in 12 teeth of 6 green monkeys. Use of the material containing potassium nitrate was found to result on the 90th day of the experiment in the formation of a biologic barrier of secondary cement at the dental root apex. Such result was not achieved with calcium hydroxide-containing material. Other advantages of potassium nitrate-containing material were detected, consisting in a more rapid recovery of structural shifts in the pulp stump and periapical tissues.     

Periapical tissues microvessels reactivity study after pulp extirpation and on different stages of endodontic treatment

Reaction of the microvessels in the gingival periapical tissues on pulp extirpation was followed by hyperemia development in microcirculatory bed, its expression increased in proportion as parodontal inflammation intensified and further strengthened after root canal filling. Microcirculation normalization in the gingival periapical tissues after endodontic treatment of chronic pulpitis and pulp extirpation as part of endodontic treatment was evident in 1 month in intact parodontium and in 6 months in case of its inflammation.     

Endodontic therapy of traumatised teeth in children.

One of the most difficult problems met with in endodontic therapy for children is the traumatized anterior tooth whose root is still incomplete. In cases where the pulp is vital, treatment by pulp capping or pulpotomy is directed to preserving the vitality of the radicular pulp to ensure completion of root formation. Calcium hydroxide remains the material of choice in both forms of treatment. Once root formation is complete, removal of the pulp residue and filling of the root canal may be performed as a preliminary to restoration by means of a post retained crown. Where the pulp is non vital, attempts to fill the funnel shaped apical part of the canal, whether from a coronal approach or by open operation for retrograde filling, have proved unsatisfactory. Many workers have shown however that a number of root filling materials and root dressings are capable of inducing either continued root growth or a closure of the apical region by a calcific scar. A detailed survey of 34 teeth treated by this method has been made and the important principles which appear to influence the success of the technique are enumerated.     

2种根尖定位仪诊断牙根纵裂的实验研究

目的研究Root ZX和Raypex5根尖定位仪是否能诊断牙根纵裂的存在及其准确位置。方法将20颗离体的双根管单根前磨牙拔髓并扩挫至根尖孔,测量原始根管的实际长度。锤击放置在根管内的根充扩大器柄部使牙根形成纵裂,测量纵裂根管的实际长度,并用Root ZX和Raypex5根尖定位仪测量仅有纵裂线而未完全分裂的纵裂牙根管长度和完全分裂的纵裂牙根管长度,对2种根尖定位仪的根管电测值与实际根管长度进行比较。结果模拟的牙根纵裂均为颊舌向裂,而且裂隙均通过根尖孔。对于仅有纵裂线而未完全分裂的纵裂牙根,Root ZX和Raypex5不能探测到纵裂位置;对于完全分裂的纵裂牙根,Root ZX和Raypex5都能探测到纵裂位置,电测长度在纵裂根管实际长度±1.0 mm范围内分别为97.5%、100%。结论根尖定位仪对仅有纵裂线的牙根纵裂无诊断价值,但对完全纵裂的牙根却有较高的诊断准确性。     

Studies on the surgical approach in vital pulp excision in relation to the root canal cross section]

The authors examined in 38 teeth the condition of the pulp stump after vital extirpation of the pulp in relation to the cross-section of the root canal. They found that the wound conditions could not be evaluated in 17 teeth as there was no pulp stump in the apical region. Relatively favourable conditions were seen in 11 teeth, which was achieved only in case of circular or oval cross-section of the root canal. These findings permit the conclusion that the state of the pulp stump after vital extirpation depends upon the anatomical conditions and the accuracy of the mechanical manipulation.     

Technical quality of root canal treatment in Taiwan

AIM: To evaluate the current technical quality of root canal treatment (RCT) in Taiwan. METHODOLOGY: A total of 1085 RCT cases, randomly selected from a large sample and representative of the Taiwanese population from April to September 2000, were evaluated by eight endodontic specialists. The qualitative evaluation of RCT cases was based on two variables: length of the root filling and density of the obturation. A root canal with both adequate filling length (the apical termination of the root filling within 2 mm of the radiographic apex) and complete obturation (no lateral or apical canal lumen visible in the apical one-third of the root canal) was defined as having good-quality endodontic work (GQEW). A tooth was defined as having a GQEW when all its canals were categorized as GQEW. RESULTS: From a total of 1867 root canals, overfilling occurred in 235 (12.6%), adequate filling length in 1152 (61.7%), underfilling in 466 (25.0%) and no filling in 12 (0.6%). Of the 1867 root canals, 710 (38.0%) demonstrated complete obturation and 1157 (62%) demonstrated incomplete obturation. GQEW was found in 650 (34.8%) root canals and 329 (30.3%) teeth. The percentage of teeth with GQEW in hospital cases (38.1%) was significantly greater (P < 0.001) than that in private clinic cases (24.3%). In addition, the frequency of teeth with GQEW in the anterior teeth (40.4%) or in the premolars (33%) was significantly greater (P < 0.001) than that in the molars (18.4%). CONCLUSIONS: Approximately 70% of the teeth receiving RCT in Taiwan were either of inadequate filling length or sealing density.     

A histopathological study of the morphological changes at the apical seat and in the periapical region after irradiation with a pulsed Nd:YAG laser

In this study, the effects of pulsed Nd:YAG laser irradiation on the apical seat and periapical region of instrumented root canals were investigated. One hundred and ninety-two teeth, including incisors and molars (239 root canals), in 18 healthy adult beagle dogs were used. After extirpation of the pulp under anaesthesia, each root canal was shaped up to at least a size 40 K-file, and then laser irradiated using the following parameters: 1 W, 15 pps for 2, 3, and 4 s; 2 W, 15 pps for 2 s. The effectiveness of debris removal and carbonization on the root canal walls immediately laser irradiation were examined and inflammation of the periapical region at 1, 2, and 4 weeks after laser irradiation was examined using light microscopy. Effective debris removal was observed in most cases in the laser-treated groups and was dependent on irradiated energy. Carbonization was observed in the irradiated root canals except at the parameter of 1 W for 2 s. Periapical inflammation was observed at 1 W for 2 s to the same extent as in the control group (P > 0.01). These results suggest that the pulsed Nd:YAG laser is useful for debris removal with no adverse effects immediately after extirpation of the pulp if appropriate parameters are selected.     

牙根发育对正畸牵引后埋伏前牙牙根及牙周组织的影响

目的:基于锥形束CT(CBCT)研究牙根发育对正畸牵引后埋伏前牙牙根及牙周组织的影响.方法:选择2018年7月-2019年3月西南医科大学附属口腔医院收治的需行上颌埋伏前牙正畸牵引治疗患者34例,共34颗上颌埋伏阻生前牙.根据牙根发育情况,分为未完全发育组和完全发育组,每组各17例.所有患者均行正畸牵引治疗.比较2组患...     

Endomethasone根充糊剂用于去髓术、根管治疗术一次法的近期疗效

目的：比较Endomethasone根管充填糊剂加牙胶尖、传统根管充填剂加牙胶尖在去髓术、根管治疗术一次法根管充填术后的急性反应及近期疗效.方法：选择活髓患牙和适合行去髓术、根管治疗术一次法的患牙共678个,随机分为2组,根管预备后实验组和对照组分别采用Endomethasone糊剂加牙胶尖、根管充填剂加牙胶尖充填根管.观察2组患牙术后1周内的急性反应及术后3、6个月的疗效.结果：实验组去髓术根充后急性反应率显著低于对照组（P＜0.01）;实验组根管治疗术根充后急性反应率显著低于对照组（P＜0.05）.实验组和对照组中,单根管患牙在去髓术、根管治疗术根充后急性反应率均显著低于多根管患牙（P＜0.01）.术后3、6个月复查,实验组去髓术、根管治疗术疗效均稍高于对照组,但无显著差异（P＞0.05）.结论：在去髓术、根管治疗术一次法中,Endomethasone糊剂充填根管较根管充填剂可有效地减少术后急性反应的发生.但在近期疗效上两者无明显差异,长期疗效有待进一步观察.     

外伤性露髓牙一次性根充法与传统根充法的疗效比较

目的比较一次性根充法和传统的分次根充法在治疗外伤性露髓牙中的长期疗效。方法选择135例病人共计182颗符合行根管治疗术指征的外伤性露髓患牙,随机分为两组,分别应用一次性根充法与传统的分次根充法进行治疗,2年后观察其远期疗效。结果经统计学处理和分析,前牙及后牙的治疗成功率二项比较,一次性根充法和传统的分次根充法的差异均无显著性。结论对外伤性露髓患牙进行的根管治疗术应用一次法与多次法在长期疗效上并无显著差异,但从方便患者就诊、减少治疗费用、减轻医生工作强度、简化治疗过程的角度来看,应尽量使用一次法。     

Influence of the canal contents on the electrical assisted determination of the length of root canals

The purpose of this study was to compare the influence of the root canal status on the determination of the root canal length by an electronic apex locator in vital and necrotic canals and canals with root canal filling retrieval. One hundred seven teeth with a total of 171 canals with various contents (105 vital pulp, 47 necrotic pulp, and 19 retrieval of root canal filling materials) were measured for root canal length in vivo with the AFA Apex Finder. The distance between the file tip and the radiographic apex was also determined on radiographs. In 86% of the evaluated roots, the file tip position as indicated by the Apex Finder was located within 0.5 mm of a point 1.0-mm short of the radiographic apex. The Apex Finder showed higher accuracy for determining the apical constriction in vital canals (93.9%) than in necrotic canals (76.6%), and this difference was statistically significant (p < or = 0.05). The Apex Finder indicated the point -1 mm +/- 0.5 mm in canals with retrieval of root canal filling materials in 68.4% of these cases, but because of the small number of retrieval cases, this is not comparable statistically with vital and necrotic cases. The authors concluded that the AFA Apex Finder is highly accurate in vital canals.     

根管系统封闭性的影响因素及其检测方法

根管治疗术是牙髓病和根尖周病常见的治疗方法,术后严密封闭根管系统可以切断根尖周组织再感染途径,确保根管治疗的远期疗效。如果根管封闭性欠佳则容易引起病原微生物及其代谢产物经过封闭材料与根管壁之间的微渗漏(包括冠方和根尖区)使根尖周组织再感染导致根管治疗失败。可见严密封闭根管系统至关重要。目前检测根管封闭性的方法较多,但关于根管系统封闭性的影响因素和检测根管封闭性的方法尚缺乏较系统的阐述。本文将影响根管封闭性的因素及检测和评价根管封闭性的方法进行综述,为检测根管充填质量和评估远期疗效提供借鉴和参考。     

The Relationship Betwpæn The Serum Protein Pattern And The Number Of Lactobacilli In The Saliva

Twenty-five human incisors and canines with healthy pulps were used. Partial pulpectomy and subsequent root filling with Bi-oxol was performed in 11 cases, while in 14 cases the entire pulp was removed and the root filling material intentionally pushed through the foramen. The teeth were examined clinically and radiographically throughout the observation period, which varied from 2–to 32 1/2 months. Eighteen of these cases were also studied histologically.

It was found that Bi-oxol in contact with vital tissue caused inflammation of varying extent. Gross overfilling resulted in more extensive inflammation than mere contact of the root filling material with the residual pulp. The root filling material was resorbed in the canal in cases of partial pulpectomy. Resorption was somewhat more rapid when the material was implanted in the periapical region. Granulation tissue invaded the canal to replace Bi-oxol. In cases of partial pulpectomy, no radiographic changes were recorded, whereas total pulpectomy with overfilling produced radiographic changes. Overfilling with severe inflammation observed histologically also gave clinical symptoms. The length of the residual pulp was found to be less in the sections than indicated by radiographs.     

Use of calcium hydroxide in the treatment of pulpitis by extirpation under analgesia

The study included 48 cases of pulpitis grade II of one-root teeth in 42 patients of either sex aged 21-35 years treated by pulp extirpation under analgesia with immediate filling of canals. In 28 teeth Biopulp was used as an intercalated substance between the periapical tissues and the material filling the canal. The control group comprised 20 teeth filled only with Endomethasone paste. The observations made immediately after filling and clinical-radiological control examination after from 6 months to 3 years showed a high usefulness of calcium hydroxide. Good results were achieved in 100% of cases while in the control group in 70% of cases.     

An audit of root canal treatment performed by undergraduate students

AIM: The objective of this study was to audit the quality of root canal treatment performed by undergraduate students on adult patients. METHODOLOGY: All root canal treatment completed by first and second clinical year undergraduates over a 12-month period were included in the study. The availability and readability of pretreatment, diagnostic length, try-in point and postoperative radiographs were noted for each case. All readable postoperative radiographs of primary treatments were examined for quality of the root filling, categorized as complete, incomplete apical, incomplete apical and lateral or not assessable. The distance from the radiographic apex of the root to the apical extent of each root filling was measured to 0.1 mm precision. RESULTS: Undergraduates performed primary treatment on 157 teeth. A postoperative radiograph was available in 97% of cases. A try-in point radiograph was unavailable in one-fifth of cases. Twenty-seven teeth (13%) were categorized as satisfactory in terms of both radiographic quality and distance of the root filling from the radiographic apex. CONCLUSIONS: Overall, the technical quality of root canal treatment completed by undergraduate students was poor.     

Apical surgery with calcium hydroxide capping of the exposed dentine: a case report

Among a variety of biomaterials that have been reported to be ideal for dental repair, calcium hydroxide has been shown to have excellent long-term biocompatibility in the pulp and periapical areas. Here we report an alternative method employing calcium hydroxide for periapical surgery in a patient who developed internal apical resorption after traumatic injury, which negatively affected the quality of the cleaning, shaping and filling of the root canal. Obturation of the root canal as far as the middle third was followed by apicoectomy and ultrasonic retropreparation, and then retrograde root filling with resin cement sealer (Sealer 26) and zinc oxide powder. Calcium hydroxide paste was applied over the exposed dentinal surface, forming a barrier over the root apex. Radiographic follow-up after 24 months showed absence of apical resorption and complete periapical bone repair associated with a continuous apical lamina dura.     

美松糊剂与氧化锌丁香油糊剂的临床疗效观察

目的：比较美松糊剂和传统的氧化锌丁香油糊剂（ZOE）根充后的效果。方法：选择96位病人双侧均有牙髓病变的牙齿192颗,且两侧病牙为相对应的牙齿或为相对应牙齿的邻牙,采用自身对照的方法,在根管充填时,一侧牙齿用美松糊剂加牙胶尖充填,另一侧用ZOE加牙胶尖充填根管,通过观察根充术后牙齿疼痛情况及持续时间来比较两组的根充效果。结果：美松糊剂组术后轻、中和重度疼痛的牙齿分别为85、10、1颗,而ZOE组分别为34、50、12颗,两组经χ2检验,P〈0.05;术后疼痛时间3、5、7d以内的美松糊剂组牙齿分别为91、5、0颗,而ZOE组分别为37、43、16颗,两组比较,亦为P〈0.05。结论：美松糊剂根充的效果要明显优于ZOE。     

Vital pulpectomy and root filling with N2 or Endomethasone

Summary. Using an aseptic and standardized endodontic technique, vital pulpectomy was performed on 16 pairs of human permanent maxillary front teeth scheduled for extraction in connection with prosthetic treatment. All the teeth had clinically sound pulps before treatment and 16 teeth were root filled with N2 and the other 16 with Endomethasone. In all cases except two, contralateral teeth were used. After 4–8 months the teeth were extracted and processed for histological examination using light microscopy. Histological examination of the residual pulp demonstrated no statistically significant differences between the two root-filling materials, concerning inflammation and the frequency of necrosis. The healing reactions, occurrence of fibrous tissue in the residual pulp and hard tissue apposition on the root canal wall, were more pronounced after root filling with N2, than after Endomethasone, but the differences were not statistically significant. Comparing the results with those after vital pulpectomy and root filling with zinc oxide-eugenol cement, total necrosis of the residual pulp was most frequent after root filling with Endomethasone, less so after zinc oxide- eugenol cement and least after root filling with N2, but the differences were not statistically significant. When estimated from the local findings, that is the histological reactions in the residual pulp, no advantages could be observed by using N2 or Endomethasone, and owing to the risk of general side effects, because of the formaldehyde content and the complex composition of the two materials routine use of N2 or Endomethasone cannot be recommended in pulpectomy.     

Root canal treatment in Denmark is most often carried out in carious vital molar teeth and retreatments are rare

AIM: To study the reasons given by a representative sample of Danish general dental practitioners (GDPs) for undertaking root canal treatment and, to investigate their confidence in performing root canal treatment on molar teeth. METHODOLOGY: A questionnaire was sent to 600 Danish GDPs randomly selected from the roster of the Danish Dental Association. They were asked to recall various factors about their experience of the last root filling they completed, including the reason for treatment and the pulp diagnosis. Self-assessments on 100-mm visual analogue scales (VAS) were reported concerning the confidence in performing root canal treatment of a molar. End-point definitions were 'very easy' (0) and 'very difficult' (100), respectively. Time reports of molar treatments were given in categorized groups. RESULTS: The most frequent reason for performing root canal treatment was caries within the tooth involved (55%). The majority of treatments involved teeth with vital pulps (54%). Retreatments were carried out in 2% of the cases. The confidence in performing root canal treatment varied but was relatively high, expressed as VAS-values below 50. The creation of an aseptic working field was regarded as the most difficult procedure followed by root canal preparation. Fifty-six percent of the responders stated a time frame of 46-75 min to complete root filling in a molar tooth. CONCLUSIONS: Root canal treatment in Denmark was reported to be undertaken most often because of caries. Treatment was typically performed in molar teeth with vital pulp. Even though apical periodontitis was frequently noted in root filled teeth, retreatments were rare. From a subjective perspective root canal treatment was not considered to be very difficult and was carried out relatively rapidly.     

去髓术、根管治疗术一次法近期临床反应的观察

目的 :观察去髓术、根管治疗术一次法的近期临床反应。方法 :选择患急、慢性牙髓炎和慢性根尖周炎 80 0例 110 0个患牙 ,随机分为两组 ,对照组 5 14牙采用常规根管治疗术即两次法 ,实验组 5 86牙采用一次法进行根管充填 ,观察各组术后近期临床反应。结果 :在治疗结束 1周内 ,对照组与实验组出现严重急性反应的比例分别为前牙 5 .2 % ,5 .1% ;后牙 9.1% ,10 .0 % (P >0 .0 5 )。结论 :一次法根管充填短期内引起急性反应比例与常规根管治疗术相比无明显差别。