三种方法修复薄弱根管冠方微渗漏的体外评价

目的评价可塑型纤维桩、预成纤维桩及根管重塑后预成纤维桩修复薄弱根管后的冠方微渗漏情况。方法选择正畸拔除上颌第一前磨牙36颗,制备形成薄弱根管。将30颗样本牙随机分为3组,A组可塑型纤维桩核系统修复、B组根管重塑后预成纤维桩核系统修复,C组预成纤维桩核系统修复,另外6颗为对照组。所有样本进行5℃-55℃冷热循环5000次后,置于0．5％碱性品红溶液中24h。将试件纵向剖开为2部分,在体视显微镜下观察各剖面修复材料与根管壁之间的微渗漏情况。用Kruskal—Wallisf法进行统计分析。结果3种方法修复后修复材料与根管牙本质之间均存在微渗漏现象,3组间无统计学差异（P〉0．05）。结论在本实验条件下,3种方法修复薄弱根管对冠方微渗漏的影响相近。     

Effects of different irrigation solutions on root dentine microhardness,smear layer removal and erosion

This study aimed to compare the effects of different irrigants on root dentine microhardness, erosion and smear layer removal. A total of 72 root dentine slices were divided into six groups, according to the final irrigants used: Group 1: 17% ethylenediamine tetra‐acetic acid (EDTA) + 2.5% NaOCl, Group 2: 7% maleic acid (MA) + 2.5% sodium hypochloride (NaOCl), Group 3: 1.3% NaOCl + mixture of tetracycline, acid and detergent (MTAD), Group 4: Smear Clear + 2.5% NaOCl, Group 5: 5% NaOCl, Group 6: saline. Vickers microhardness values were measured before and after treatment. In total, 42 root‐halves were prepared for scanning electron microscope to evaluate the amount of smear and erosion in the coronal, middle and apical thirds. Data were analysed using two‐way anova , Duncan and two‐proportion z‐tests. Maleic acid showed the greatest reduction in dentine microhardness (P < 0.05), followed by EDTA and MTAD. EDTA, maleic acid, MTAD and Smear Clear removed smear layer efficiently in the coronal and middle thirds of root canal. However, in the apical region, maleic acid showed more efficient removal of the smear layer than the other irrigants (P < 0.05).     

Healing responses following transverse root fracture: a historical review and case reports showing healing with (a) calcified tissue and (b) dense fibrous connective tissue

Background

The understanding and management of transverse intra‐alveolar root fractures has evolved to its current high level of sophistication and clinical success from foundations laid down by histological studies as early as the mid‐nineteenth century.

Significance

The aim of the review was to highlight those earlier histological reports and studies that have contributed to the current understanding of the biological processes involved in the healing of transverse root fractures. Healing of a transverse root fracture by calcified tissue was demonstrated histologically by Howe in 1926, while Boulger in 1928 showed the two other patterns of root fracture healing, namely the interposition of fibrous connective tissue and the interposition of bone and periodontal ligament around both fractured segments. Other major histological reports around that time came from members of the so‐called ‘The Vienna group of Illinois’, who had a significant influence in the development of oral biology worldwide. Other important reports and an experimental study emanated from Germany and Switzerland in the late 30s and early 40s, followed in the 1950s and early 1960s by histological material principally from Sweden, Denmark, France, the USA and Britain. Jens Andreasen and Erik Hjörting‐Hansen's landmark paper in 1967 included new histological reports and a classification of healing responses following transverse root fractures. The expansion of knowledge related to root fractures since that time has been exponential, with major contributions from Scandinavia and several other countries.

Case reports

Accompanying the historical review are two case reports with histology of root fracture healing by (a) calcified tissue and (b) dense fibrous connective tissue. The role of the pulp and the periodontal ligament in the repair process is described and the clinical significance discussed with particular emphasis to diagnosis and orthodontic management.     

Usefulness of cone‐beam CT in the evaluation of a spontaneously healed root fracture case

Horizontal root fractures (HRF) usually affect anterior teeth of male patients as a result of trauma. The consequences can be complex because of combined damage to different tissues, but it has been reported that root fractures undergo healing in majority cases. Diagnosis of HRF must be based on clinical findings, sensibility tests, and radiographic examination. The cone‐beam computed tomography (CBCT) has already been proven to be superior among other radiographic modalities for diagnostic imaging of root fractures. However, CBCT in these cases needs to be used in a careful manner, and only when the radiation exposure should be justified by the potential diagnostic benefits and improvement of the treatment results. This case report describes a case of spontaneously healed horizontal root fracture with displacement of the fragments and discusses the usefulness of CBCT in the follow‐up of root fractures cases.     

自调节根管锉的特性和临床应用评价

根管预备（根管清理和根管成形）是根管治疗的关键步骤。为了达到良好的根管预备目的,各种先进器械和新型材料不断涌现。从标准不锈钢根管锉到旋转镍钛锉系统的相继应用,根管预备的质量和效率得到了大幅的提高;然而这两种临床常用的器械并没有完全达到根管预备的目标,尤其在三维影像上仍存在着明显的缺陷。自调节根管锉（SAF）这种新型镍钛器械的诞生,为根管预备技术带来了突破。其全新的设计克服了传统根管锉在柔韧性和可塑性等方面的不足,其自带的冲洗装置实现了根管冲洗和成形的同步操作,根管清理更为完善。本文就SAF的特性、力学性能和临床应用等研究进展作一综述。     

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目的评价自制洗必泰凝胶对粪肠球菌的抑菌效果。方法于2011年9月至2012年3月在辽宁省疾病控制中心微生物实验室采用纸片扩散法药敏实验测定生理盐水（A组）、Vitepex（B组）、2％洗必泰溶液（c组）和洗必泰凝胶（D组）对粪肠球菌形成的抑菌环直径并进行统计学分析。结果C组和D组的抑菌环直径明显大于B组,差异有统计学意义（p〈0．01）;C组和D组抑菌环直径的差异无统计学意义（P〉0．05）;4组组内各时间点抑菌环直径差异均无统计学意义（P〉0．05）。结论洗必泰凝胶是根管再治疗的理想消毒药物。     

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目的观察STA麻醉仪对牙科畏惧症患者的临床治疗作用。方法回顾2011年1—12月中国医科大学口腔医学院综合急诊科门诊收治的牙科畏惧症患者100例,应用STA麻醉仪治疗患者（试验组）44例,手推注射麻醉患者（对照组）56例。记录麻药起效、失效时间,患者自行评估疼痛程度,同时计算麻醉有效率,对两组结果进行数据分析比较。结果试验组的麻药生效及失效时间均小于对照组（P〈0．05）;试验组疼痛明显轻于对照组（P〈0．05）;试验组的麻醉有效率明显高于对照组（P〈0．05）。结论STA麻醉仪能有效地降低牙科畏惧症患者治疗中的恐惧程度,值得推广使用。     

Renal carcinoma relapse presenting as a peripheral nerve sheath tumor: A case report and brief review of the literature

We report a rare case of renal carcinoma metastasis involving a lumbar nerve root. Metastases to nerve roots are rare occurrences, and to our knowledge, only six cases have been reported so far in the literature. The patient in this report presented with weakness in the right lower limb and intractable pain irradiating along the L5 dermatome. MRI findings revealed a right-sided L5 nerve root mass, suggestive of a schwannoma, involving the spinal ganglion and its extraforaminal region. Complete macroscopic resection of this mass was performed, and histopathologic analysis confirmed the lesion to be a metastasis of a renal clear cell carcinoma. Local radiotherapy was given and tyrosine kinase inhibitors administered. At 5 months, the patient was pain-free and his right limb weakness had completely resolved. A tumoral recurrence could be observed on the control MRI 5 months after surgery. This report presents the first case of a patient with a renal clear cell carcinoma metastasis to a L5 nerve root, as well as a brief review of previous cases of metastases to peripheral nerve roots.