Influence of Preoperative Mechanical Allodynia on Predicting Postoperative Pain after Root Canal Treatment: A Prospective Clinical Study

IntroductionOdontogenic pain can manifest as pulpal pain, periapical pain (mechanical allodynia), or both. This study aimed to assess the changes in the intensity of mechanical allodynia (MA) and to identify predictors of postoperative pain after root canal treatment (RCT).MethodsIn total, 579 consecutive patients who required RCT were enrolled; we included patients with asymptomatic pulpal diagnoses to avoid any effects of preoperative spontaneous pain on postoperative pain and to evaluate MA independently. Using a visual analog scale (VAS), patients separately indicated the intensity of spontaneous pain, tenderness to percussion, and pain on biting; these measurements were performed before treatment (preoperative pain), at the beginning of each visit (postpreparation pain), and daily for 1 week after RCT (postobturation pain). For analytical purposes, patients were subdivided into 2 groups based on the intensity of preoperative MA (none to mild [VAS <4] or moderate to severe [VAS ≥4]) to evaluate changes in MA and predictive factors of moderate to severe postoperative pain. A generalized estimating equation, repeated-measures analysis of variance, and logistic regression analysis were used.ResultsAlthough the intensity of MA was significantly higher in the moderate to severe group after the initiation of RCT (P < .05), 93% of them experienced alleviation in MA, and 30% of patients in the none to mild group experienced an increase in MA. After adjusting for clinical variables, moderate to severe preoperative MA and the presence of necrotic pulp were significantly correlated with moderate to severe postoperative pain with an odds ratio of 4.107 and 0.286, respectively.ConclusionsModerate to severe preoperative MA was a predictive factor of postoperative pain in patients undergoing RCT.     

A Novel Polyurethane Expandable Root Canal Sealer

IntroductionEndodontic sealers play a vital role in the obturation of root canal space. The aim of this study was to evaluate the utility of a recently developed polyurethane expandable sealer (PES), along with its cytotoxicity and dimensional changes.MethodsL929 fibroblasts and an cell viability assay (MTS assay) were used to determine the cytotoxicity of dental sealers (AH Plus [Dentsply Maillefer, Ballaigues, Switzerland], Sure-Seal Root [Sure Dent Corporation, Gyeonggi-do, South Korea], and the PES) at 24, 48, 72, and 96 hours. An advanced choroidal neovascularization model was used to assess the effect of these sealers on angiogenesis. Thirty-six extracted single-rooted human teeth were prepared and randomly divided into 3 groups (n = 12). Obturation was performed with gutta-percha and a sealer using lateral compaction as follows: group 1, AH Plus; group 2, Sure-Seal; and group 3, PES. The average depth of sealer penetration into dentinal tubules was measured with a scanning electron microscope. Data were analyzed using 1-way analysis of variance and post hoc Tukey tests (level of significance, P < .05).ResultsThe values of MTS, choroidal neovascularization, and the penetration depth of PES were significantly higher than in other experimental groups (P < .05). The lowest values were noted in specimens of AH Plus, whereas the highest were detected in the PES group.ConclusionsPES showed promising results in terms of biocompatibility and dentinal tubule adaptation and penetration.     

Effects of Endodontic Infections on the Maxillary Sinus: A Case Series of Treatment Outcome

This article shows the follow-up of several cases of maxillary sinusitis of dental (usually endodontic) origin, with different manifestations, diagnostic challenges, and outcomes.Cases from 14 patients from 3 countries and treated by 7 different endodontists are presented, all of them with inflammatory sinus changes represented by mucositis, osteoperiostitis, and/or partial/full obstruction. All cases showed dental and/or sinus signs/symptoms that resolved after dental management. In 13 cases, the sinus condition had an endodontic origin, 4 of them concurrently with periodontal involvement. In 1 case, sinusitis was caused by trauma to the face. All cases but 1 had a satisfactory response of the periradicular tissues and maxillary sinus to treatment that consisted of root canal therapy, root amputation, extraction, or trauma management.The successful management of most cases reported in this article emphasizes the importance of endodontics as a specialty engaged in saving teeth and promoting health not only in the oral cavity but also in other areas that may be affected by infections of endodontic origin, including the maxillary sinus.     

Influence of Cavity Designs on Fracture Behavior of a Mandibular First Premolar with a Severely Curved h-shaped Canal

IntroductionThis study aimed to investigate the fracture behavior of a mandibular first premolar with a severely curved h-shaped canal using the extended finite element method.MethodsFollowing the micro–computed tomographic data, models of the intact tooth, the conservative endodontic cavity (CEC), the modified conservative endodontic cavity (MCEC), and the traditional endodontic cavity (TEC) were created. All models were subjected with a total load of 600 N perpendicularly to the contact areas. The distributions of maximum principal stress were recorded. The evolution of cracks in the enamel and dentin was simulated with the extended finite element method.ResultsThe intact tooth showed the highest crack initiation load and the smallest stress concentration area. The CEC and MCEC showed higher crack initiation loads and smaller stress concentration areas compared with the TEC. On the occlusal surface, tensile stress was centralized around the distal fossa and the distal margins of cavities. In the root, the stress was concentrated at the mesiolingual side for all models and at the internal surface on the bifurcation section for the CEC. Cracks originated at buccal side of the distal fossa and microcracks were formed confined to the enamel, and then cracks occurred in the dentin below the bone level.ConclusionsFor the mandibular first premolar with a severely curved h-shaped canal, the MCEC preserved the fracture resistance equally as well as the CEC and reduced the stress concentration on the bifurcation section. The fracture initiated in the enamel, forming microcracks on the buccal side of the distal fossa and then occurred as an irreparable fracture in the dentin.     

青藤碱对切口痛模型大鼠的镇痛效应及其中枢神经系统中P物质含量的影响

目的观察青藤碱对切口痛模型大鼠疼痛敏感行为及其脑脊液、脊髓中P物质含量的影响。方法 SD大鼠30只,随机分为模型组（Model）、氯诺昔康组（Lornoxicam,8mg·Kg-1）、青藤碱高剂量组（Sin-H,20mg·Kg-1）和青藤碱低剂量组（Sin-L,10mg·Kg-1）。采用机械痛敏和热痛敏测试,评价大鼠的疼痛行为。放免法检测大鼠脑脊液及脊髓L6-L8中P物质含量。结果切口痛模型大鼠的机械撤足阈值、热刺激痛感缩足时间明显改变。青藤碱高、低剂量和阳性药投与后均显示了明显的镇痛效果,其中青藤碱高剂量组镇痛效应指标优于阳性对照药氯诺昔康;给药各组大鼠脑脊液、脊髓中的P物质含量与模型组相比都下降显著,差异有统计学意义（P〈0.05）,而以青藤碱高剂量组的脑脊液P物质浓度抑制最为明显。结论青藤碱能够减轻切口痛模型大鼠疼痛敏感行为,减少P物质在中枢神经系统的释放,后者可能是青藤碱产生镇痛作用的重要机制之一。     

上颌中切牙种植进入鼻腭管的研究进展

上颌中切牙缺失后常伴随唇侧骨壁吸收,造成唇腭向牙槽嵴宽度减少,出于前牙区美学修复的考量,种植位点常偏腭侧。鼻腭管(nasopalatine canal, NPC)在解剖位置上紧邻上颌中切牙种植位点,造成术中植体可能进入NPC,伴随腭部感觉异常和（或）种植体非骨结合,甚至发生种植体脱落。NPC穿孔作为上颌中切牙种植手术的并发症之一,不仅降低种植术成功率,还引起患者负面心理情绪。故本文就上颌美学区种植NPC穿孔的发生率、影响NPC穿孔相关因素、临床检查及诊断、预防措施及临床治疗方法等作一综述,为美学区种植避免NPC穿孔提供理论参考。     

Atrioventricular canal defect in patients with RASopathies

Congenital heart defects affect 60-85% of patients with RASopathies. We analysed the clinical and molecular characteristics of atrioventricular canal defect in patients with mutations affecting genes coding for proteins with role in the RAS/MAPK pathway. Between 2002 and 2011, 101 patients with cardiac defect and a molecularly confirmed RASopathy were collected. Congenital heart defects within the spectrum of complete or partial (including cleft mitral valve) atrioventricular canal defect were diagnosed in 8/101 (8%) patients, including seven with a PTPN11 gene mutation, and one single subject with a RAF1 gene mutation. The only recurrent mutation was the missense PTPN11 c.124 A>G change (T42A) in PTPN11. Partial atrioventricular canal defect was found in six cases, complete in one, cleft mitral valve in one. In four subjects the defect was associated with other cardiac defects, including subvalvular aortic stenosis, mitral valve anomaly, pulmonary valve stenosis and hypertrophic cardiomyopathy. Maternal segregation of PTPN11 and RAF1 gene mutations occurred in two and one patients, respectively. Congenital heart defects in the affected relatives were discordant in the families with PTPN11 mutations, and concordant in that with RAF1 mutation. In conclusion, our data confirm previous reports indicating that atrioventricular canal defect represents a relatively common feature in Noonan syndrome. Among RASopathies, atrioventricular canal defect was observed to occur with higher prevalence among subjects with PTPN11 mutations, even though this association was not significant possibly because of low statistical power. Familial segregation of atrioventricular canal defect should be considered in the genetic counselling of families with RASopathies.     

Tooth autotransplantation using an interdisciplinary approach to rehabilitation in a young patient: Case report with 7-year follow-up

This case report demonstrates the possibility of functional and aesthetic rehabilitation using an interdisciplinary approach in a child following avulsion of a tooth. Autotransplantation after the development of calcific metamorphosis of the pulp and acute apical periodontitis provided satisfactory repair after root canal treatment. A 7-year-old white boy avulsed the right maxillary central incisor (tooth 11). The extra-alveolar time exceeded 60 minutes, and this triggered external replacement resorption of the avulsed tooth. At 11 years of age, the child underwent tooth autotransplantation. After 4 years of follow-up, intraoral clinical and radiographic examination led to the diagnosis of calcific metamorphosis of the pulp and acute apical periodontitis. The patient had minimally invasive root canal treatment, orthodontic treatment and esthetic rehabilitation with a porcelain crown. Control periapical radiography and tomography of the autotransplanted tooth after 7 years revealed bone repair in the periapical region. This case report indicates that tooth autotransplantation can be used to replace anterior teeth after avulsion followed by replacement resorption. Interdisciplinary management helped to maintain the esthetics and function of the rehabilitated area.     

A review of epidural simulators: Where are we today?

Thirty-one central neural blockade simulators have been implemented into clinical practice over the last thirty years either commercially or for research. This review aims to provide a detailed evaluation of why we need epidural and spinal simulators in the first instance and then draws comparisons between computer-based and manikin-based simulators. This review covers thirty-one simulators in total; sixteen of which are solely epidural simulators, nine are for epidural plus spinal or lumbar puncture simulation, and six, which are solely lumbar puncture simulators. All hardware and software components of simulators are discussed, including actuators, sensors, graphics, haptics, and virtual reality based simulators. The purpose of this comparative review is to identify the direction for future epidural simulation by outlining necessary improvements to create the ideal epidural simulator. The weaknesses of existing simulators are discussed and their strengths identified so that these can be carried forward. This review aims to provide a foundation for the future creation of advanced simulators to enhance the training of epiduralists, enabling them to comprehensively practice epidural insertion in vitro before training on patients and ultimately reducing the potential risk of harm.