Strengthening and restoration of immature teeth with an acid-etch resin technique

Abstract Endodontic treatment with subsequent restoration of 3 immature incisors with horizontal fractures in the cervical region is described. In 1 tooth the fracture occurred supragingivally, whereas in 2 others the fracture was such that the root margins were between 1 and 2 mm subosseous. In these teeth proper access to the roots was established by means of orthodontic extrusion and/or periodontal surgery. After endodontic treatment, the gutta-percha was removed from the root canals to a level 2 to 3 mm apically to the osseous crest. The root canal dentin was acid-etched and a post to retain a crown was cemented into the canal with a composite resin. The resin will then penetrate into the dentinal tubules of the root canal walls and strengthen the root to such a degree that it becomes restorable. Semipermanent composite resin crowns and, in one instance, a more permanent porcelain crown were used to restore the teeth.     

Infected immature teeth treated with surgical endodontic treatment and root-reinforcing technique with glass ionomer cement

Abstract –  The authors propose surgical endodontic treatment of immature teeth characterized by necrosis and infection, especially after failure of apexification or in the presence of older, fibrous, and extensive lesion. A glass ionomer cement, autopolymerizable and condensable, is used as retro-filling material and as a reinforcement material for the canal walls. The variety of different cases presented here show that this rapid technique is reliable and reproducible.     

Pulp capping of immature teeth with anatomic anomalies

Abstract This case report describes the treatment of two immature teeth with anatomic anomalies which created plaque retentive areas and in one case occlusal disturbance. Periodontal and pulpal consequences were inevitable. Reshaping of the teeth was carried out which as expected led to exposure of the pulp in both instances. Pulp capping was then performed under aseptic conditions. The vitality of the teeth was maintained and continued root development was observed.     

Structural resistance in immature teeth using root reinforcements in vitro

Abstract –  The purpose of this study was to evaluate in vitro the efficacy of root reinforcements by light-cured composite resin or zirconium fiber post in simulated immature non-vital teeth. Fifty-six bovine incisors teeth were used for this study. The crown of each tooth was removed in the medium third to obtain a standard length of 30 mm. The specimens were divided into four groups ( n  = 14): G1) the root canals were instrumented and enlarged to simulate immature non-vital teeth and were reinforced with a light-cured composite resin using a translucent curing post (Luminex system); (G2) the specimens were instrumented, enlarged and they received root reinforcement with zirconium fiber post; G3 (positive control): they received similar treatment to the G1 and G2 groups, but did not receive root reinforcement; G4 (negative control): the roots were not weakened and did not receive reinforcement. Every tooth was submitted to compressive force using an Instron testing machine with an angle of 45° at a speed of 1 mm min⁻¹ until the fracture. The results showed a markedly increased resistance to fracture in the G1 and G2 ( 122.38 and 122.08 kgf, respectively). Among the results of G1 and G2 there was not any significant difference (P > 0.05) but they were significantly different from the control groups (P < 0.05). The conclusion is that the use of root reinforcements with zirconiun fiber post or composite resin can increase significantly the structural resistance of the weakened teeth, decreasing the risk of the fracture.     

Endodontic retreatment: a rational approach to non-surgical root canal therapy of immature teeth

Abstract The specificity of retreating immature teeth involves generally a broadly wide open apex and/or an inverted root canal conicity (apical opening wider than the root canal orifice), a periapical pathology leading often to a continuous canal exudation and thin and fragile dentinal walls. Nonsurgical endodontic retreatment of immature teeth consists at first in removing coronal and root canal iatrogenic obstructions in order to regain total canal patency. Apexification is then the treatment of choice, preceding a final gutta-percha obturation. The present article outlines a step-by-step rational approach to the root canal retreatment of immature teeth, pertaining to their biomechanical and pathological specificity.     

2015年南京市353例年轻恒牙外伤的临床分析

［摘要］目的 探讨学龄儿童年轻恒牙外伤的临床特点,更好地维护口腔健康。方法 对2015年1月至12月期间在南京医科大学附属口腔医院儿童口腔科就诊的353例5~12岁学龄儿童年轻恒牙外伤病例的年龄、性别、外伤后就诊时间、外伤牙位、外伤类型及Nolla分期进行回顾性分析,总结其临床特点。 结果 男女比例为2.33∶1;12月份最高发;7～9岁为高发年龄;多在外伤后2~24 h就诊;上颌中切牙最多见;釉质-牙本质折断及亚脱位最多;硬组织损伤中以Nolla 9期最常见。 结论 年轻恒牙外伤有其独有的特点,应加强牙外伤的预防保健宣传,提高公众的就诊意识。     

Pulp revascularization of replanted immature dog teeth after different treatment methods

Abstract – The purpose of the present study was to determine the effect of topical treatment with doxycycline and/or the application of unfilled resin to the anatomical crown on the occurrence of revascularization in reimplanted dog teeth. Ninety-six teeth in 4 young mongrel dogs were used. Eighty one teeth were atraumatically extracted and divided into four groups. Group 1, 17 teeth were kept dry for 5 min and then replanted. Group 2, 21 teeth were soaked with a freshly prepared solution of doxycycline (1 mg/20 mL saline) for 5 min before replantation. Group 3, 23 teeth were soaked with the doxycycline solution for 5 min, and then replanted. The crowns were coated with 2 layers of light cured unfilled resin. Group 4, 20 teeth were kept dry for 5 min, and then replanted. The crowns were treated as with the teeth in Group 3. Three months after surgery, radiographic evaluation revealed that 27 teeth had continued root development and 32 teeth showed arrested root development with periradicular pathosis. The remaining 17 teeth, which had arrested root development but no signs of periradicular pathosis, were all histologically evaluated for final assessment. The occurrence of revascularization according to treatment group was 29.4%, 60%, 60%, 36.8% in Group 1, 2, 3, and 4, respectively. A multiple logistic regression analysis in SAS indicated there was no significant association between vitality and dog ( P =0.7564). Soaking for 5 min in doxycycline significantly increased the revascularization rate ( P =0.024) while the addition of resin to the crown did not result in an increased incidence of pulp revascularization ( P =0.823).     

Histological assessment of human regenerative endodontic procedures (REP) of immature permanent teeth with necrotic pulp/apical periodontitis: A systematic review

The aim of this study was to systematically review the histological evidence of the neo‐formed tissues inside the root canals of human teeth having previously received regenerative endodontic treatment. An electronic research was performed in the MEDLINE, Web of Science, Scopus and Cochrane Library databases using controlled vocabulary. The retrieved studies were screened by two reviewers according to the predetermined inclusion and extrusion criteria and were full‐text‐evaluated. Research resulted in 160 studies. Among them, twelve fitted the inclusion criteria and were critically appraised. The tissues formed in the root canals of immature human teeth treated with REP indicate repair or a combination of repair and regeneration. Pulp remnants and healthy periapical tissues seem to improve regeneration. The level of available evidence was low. Further clinical studies are needed in order to establish the appropriate treatment protocol related to the pretreatment status of the dental pulp and the periapical tissues.     

犬年轻恒牙血管再生法动物模型建立的影响因素

目的：探讨犬年轻恒牙血管再生法动物模型建立的影响因素。方法：杂种犬3只,选取牙根未发育完成的上颌恒前牙及下颌恒前磨牙共36个牙根为样本,建立根尖周炎模型后构建血管再生法动物模型。结果：3个牙根未形成血凝块,4个牙根MTA充填不佳,7个牙根出现了牙周炎,5个牙根冠折,1个牙根脱落。结论：血凝块的质量,矿化三氧化聚合体（MTA）的充填技术,牙周炎的出现,疼痛等因素对模型的建立有一定的影响。     

血管再生治疗犬年轻恒牙根尖周炎的实验研究

目的：比较血管再生和根尖诱导成形术治疗犬年轻恒牙根尖周炎的效果。方法：选用3只5-6个月犬的30颗双根前磨牙,建立根尖周炎模型,三联抗生素糊剂消毒后,随机分为三组,即血管再生组、根尖诱导组和空白对照组。于术后4周、8周、12周分别拍摄X线片,比较根尖愈合情况。术后12周处死动物,常规制作组织切片,观察管腔内再生组织的成分以及根尖硬组织形成情况。结果：①X线观察：三组均可看到根尖闭合影像,两实验组的根尖闭合率优于对照组（P〈0．05）,实验组之间差异无统计学意义（P〉0．05）。②组织形态学观察：血管再生组和对照组有类似于牙骨质样组织（管内牙骨质）从根尖孔向内延伸,在管壁沉积,管腔内出现骨样组织（管内骨组织）,共同促使牙根伸长和管壁增厚,且血管再生组的两种组织发生率优于对照组（P〈0．05）,根尖诱导组未见此两种组织。结论：血管再生在管壁增厚和牙根伸长等方面优于根尖诱导成形术。     

Pulp revascularization for immature replanted teeth: a case report

Immature avulsed teeth are not usually treated with pulp revascularization because of the possibility of complications. However, this therapy has shown success in the treatment of immature teeth with periapical lesions. This report describes the case of an immature replanted tooth that was successfully treated by pulp revascularization. An 8‐year‐old boy suffered avulsion on his maxillary left lateral incisor. The tooth showed incomplete root development and was replanted after 30 minutes. After diagnosis, revascularization therapy was performed by irrigating the root canal and applying a calcium hydroxide paste and 2% chlorhexidine gel for 21 days. In the second session, the intracanal dressing was removed and a blood clot was stimulated up to the cervical third of the root canal. Mineral trioxide aggregate was placed as a cervical barrier at the entrance of the root canal and the crown was restored. During the follow‐up period, periapical repair, apical closure and calcification in the apical 4 mm of the root canal was observed. An avulsed immature tooth replanted after a brief extra‐alveolar period and maintained in a viable storage medium may be treated with revascularization.     

年轻恒牙牙髓再生的临床应用进展

目前,对于未发育成熟、根尖孔未闭合的牙髓坏死和根尖周炎的年轻恒牙,临床上主要的治疗方法为根尖诱导成形术,但根尖诱导成形术预后发生根折的概率较大.随着牙髓再生术临床成功病例报告的逐渐增多,越来越多的患者接受牙髓再生治疗.本文收集国外2010—2015年的35篇文献92例病例进行总结并分析,对牙髓再生术的临床应用进展作一综述.     

Root fracture in immature anterior teeth followed for 15 years

Abstract –  We report a case of injury to an immature tooth, observed over a period of 15 years. In 1987, a 9-year-old boy fell down in a schoolyard. The right central incisor demonstrated palato-version and radiographic observations revealed that the roots of both central incisors were incomplete. Further, a root fracture in the apical region of the central incisors was observed. During the first treatment visit, the right central incisor was repositioned and both teeth splinted. After confirming that the line of fracture was aligned, the fixation was continued for 2 months. The teeth were examined periodically for the next 15 years. Both teeth had favorable outcomes with continued root development of both the apical and coronal segments with good apposition of the fracture lines.     

Periodontal healing after intentional auto-alloplastic reimplantation of injured immature upper front teeth

BACKGROUND/AIMS: Conventional endodontic treatment results in high complication quota when performed in immature teeth. Intentional reimplantation with extraoral insertion of an endodontic implant (auto-alloplastic reimplantation) is an alternative. METHOD: In a retrospective study, the healing of 40 teeth reimplanted intentionally according to this method in patients aged 7 to 15 years was evaluated. Clinical tests (palpation, percussion sound, periotest values) and radiographical examinations were used to determine the type of periodontal healing (inflammatory resorption/periodontitis apicalis; replacement resorption/ankylosis; normal healing). RESULTS: Mean lifetime of the replanted teeth was 59.2+/-42.5 months, estimated survival time on the basis of the Kaplan-Meier analysis was 99.5 months. 17 teeth (42.5%) were classified as failures, mostly due to inflammatory resorption or periodontitis apicalis. Further investigations demonstrated that success rate and retention period of intentionally replanted teeth depend on the preoperative condition of the pulp. Teeth with preoperative infection suffered frequently from inflammatory resorption or periodontitis apicalis after being replanted (14 of 28 teeth). Estimated survival time according to Kaplan-Meier was 75.5 months. In contrast, inflammations or progressive resorptions were not observed in teeth without preoperative infection of the pulp. All these 12 teeth showed normal periodontal healing and regular tooth mobility. In the absence of any pathology in clinical or radiological findings after an average functional period of 72.3 months, the prognosis can be presumed excellent. Estimated survival time of 148.3 months according to Kaplan-Meier differs significantly from survival time of teeth infected preoperatively. CONCLUSIONS: From the results of this investigation, it may be concluded that an infection of the pulp - due to delay of treatment or attempts at endodontic therapy - should be avoided before intentional replantation of immature front teeth with pulp necrosis. Periodontal healing of the autologous root is not impaired by the insertion of posts made of Al2O3-ceramics or titanium. The inserted posts do not ankylose. Orthodontic movement of auto-alloplastically replanted teeth is possible.     

Efficacy of laser Doppler flowmetry for the diagnosis of revascularization of reimplanted immature dog teeth

Abstract – This study was performed to assess if laser Doppler flowmetry (LDF) is an improved method for the detection of revascularization of replanted teeth. Teeth were extracted and reimplanted under different experimental conditions. LDF readings were taken before extraction and weekly for 3 months. In control teeth, LDF baseline readings were taken and then repeated after the apical blood vessels were cut surgically. At the end of 3 months it was determined radiographically and histologically whether revascularization had occurred, i.e. vitality had returned. Results: LDF readings correctly predicted the pulp status (vital vs. non-vital) in 83.7% of the readings. 73.9% (17 of 23) were correct for the vital teeth and 95% (19 of 20) were correct for the non-vital teeth. Fisher's exact test (2-tail) indicated that there was no significant association between the efficacy of LDF and tooth type ( P= 0.166), although P2 was the least accurate tooth tested. Wilcoxon's matched-pair signed rank test demonstrated that in the revascularized (vital) teeth, the flux value between the baseline and week 2 dropped significantly ( P= 0.0001), increased significantly from week 2 to week 4 ( P= 0.0001) and then decreased steadily until week 12. However, at week 12 the flux was still significantly higher than at week 2 ( P= 0.010). In the teeth that failed to revascularize, the flux value dropped significantly by weeks 1 and 2 ( P= 0.004 and P= 0.0001, respectively). Flux values did not increase from week 2. A Fast Fourier Transform (FFT) analysis confirmed a pulse of dominant frequency of 2 Hz in the teeth that returned to vitality and the lack thereof in those that stayed non-vital. One tooth in which the flux value evaluation indicated a non-vital tooth but the radiographic/histologic findings showed vital (false negative) possessed a pulse of dominant frequency and proved by this method to have successfully revascularized.