Endodontic treatment of a hypertaurodontic mandibular left second molar in a patient with many taurodonts combined with multiple pulp stones

Taurodontism is a rare embryologic anomaly of teeth, defined by an apical displacement of the furcation of roots and enlarged pulp chambers. Taurodontism has been classified as hypo‐, meso‐ or hypertaurodontism according to the severity of the anomaly. The aim of this case report was to illustrate a clinical case with multiple bilateral taurodonts and to describe the endodontic management of the hypertaurodontic mandibular left second molar with a C‐shaped canal and extensive dental pulp calcifications. A healthy 20‐year‐old male patient was referred for the endodontic treatment of his lower left second molar. Cone beam computed tomography revealed a C‐shaped root canal configuration and several dental pulp calcifications in this tooth. The endodontic treatment was performed in two appointments under an operating dental microscope. A panoramic radiograph, made during the 18 months follow‐up appointment, revealed nine other taurodontic molars, most of them associated with dental pulp calcifications.     

Human parotid proline-rich proteins: correlation of genetic polymorphisms to dental caries

Parotid saliva contains a variety of proline-rich proteins. This study found that, among 306 children between the ages of 5 to 15 years, there is a significant increase in the decayed-missing-filled tooth surface (DMFS) score of the permanent teeth with age in children with the specific proline-rich protein phenotypes Pa and Pr. However, the increase in DMFS score of the permanent teeth of children was significantly greater in children with Pa+ and Pr22 than in those with the other phenotypes (Pa- or Pr11 and Pr12). The previously established close correlation between the Pa and Pr phenotypes and the genetic variants of salivary peroxidase (a powerful antibacterial system in the oral cavity) may provide an explanation for the relationship of certain proline-rich protein phenotypes to dental caries.     

Treatment time analysis for extensive amalgam restorations

The treatment times for the fabrication of Extensive Amalgam Restorations (EAR) as recorded in a longitudinal clinical trial at the Dental School in Nijmegen were analyzed. 269 EAR's with different retention methods were made on molars by three operators. A mean total treatment time of 60 min was found. The factor operator had a significant influence on all treatment phases resulting in a 26% difference in total treatment time between operators. Also significant influences were found in some treatment phases for the factor retention, side location of the tooth and extension of the restoration. The results of this study with regard to treatment times must be considered from the perspective of the quality of the care provided.     

Cyclic Neutropenia Terminating in Permanent Agranulocytosis

ABSTRACT A patient with cyclic neutropenia was followed for 20 years. After 16 years she developed a permanent agranulocytosis, and lived for nearly four years without neutrophils in the peripheral blood. Neither prednisone, lithium nor Jeuco- and plasmapheresis had any effect on the neutrophil count.     

西藏那曲地区藏族学生恒牙龋病现状调查

目的了解那曲地区藏族学生龋病患病情况,为当地制定口腔预防保健措施提供基线资料。方法采用单纯随机抽样方法,按照WHO 1997年的《口腔健康调查基本方法》,对12～17岁的471名藏族学生进行恒牙龋病检查。结果藏族学生恒牙总患龋率为56.7%,男生患龋率为53.9%,女生患龋率为59.1%,差异无统计学意义(χ2=1.258,P=0.262);龋均为(4.09±2.11),男生龋均为(4.04±2.10),女生龋均为(4.13±2.11),差异无统计学意义(t=-0.646,P=0.518)。结论那曲地区藏族学生恒牙龋病患病率较高、程度较重,预防治疗措施急需加强。     

采用永磁悬浮的永久性左心室辅助装置

研制出一台采用永磁轴承的左心室辅助装置（LVAD）。该装置包括一个定子和一个转子，采用径向驱动方式；转子包括驱动磁钢和叶轮，电机定子线圈和泵壳组成定子。装置设计采用了一种特殊结构的永磁轴承。转子的位置测量表明，转子稳定悬浮的前提条件是必须有较高的转速（大于3250r／min）且流量大于1L/min。用猪血为介质所做的液动力测试表明，当转速达到3500r／min～4000r／min时，血泵输出流量达到4L/min～6L/min，输出压力达到100mmHg。该装置重200g，最大处直径为40mm。     

Oligodontia, short stature and small head circumference with normal intelligence

Complete absence of third molars and mandibular permanent second molars is reported in a 19-year-old female, with occipito-frontal head circumference and height at the 3rd centile. The patient's intelligence, appearance and physical examination were normal. Direct count of the patient's sweat pores in different areas of the palms and digits was normal. Microcephaly, short stature and normal intelligence have been reported in two families as a distinct autosomal dominant syndrome. To the best of our knowledge, oligodontia, in addition to these findings, has not been previously reported.     

不同方法预防儿童第一恒磨牙龋坏的效果评价

采用窝沟封闭、氟凝胶、含氟泡沫、口腔卫生宣教(OHI)对泉州市二年级儿童(7~8岁)第一恒磨牙龋坏的预防效果进行评价,尝试寻找最适合群体儿童的第一恒磨牙龋坏预防方法。方法 2017年采用整群随机抽样的方法在泉州市区选取5所学校的二年级儿童1 768名,检查第一恒磨牙萌出情况及患龋情况,分为5组,分别为空白对照组(n=313)、口腔卫生宣教组(n=421)、氟保护漆组(n=267)、含氟泡沫组(n=438)、窝沟封闭组(n=329),观察两年后五组学生防龋效果。结果 五所小学共有1 748名儿童完成两年的观察研究,随访率为98.87%。干预两年后,氟保护漆组新增龋均及龋面均高于其他四组,窝沟封闭组新增龋均及龋面均低于其他四组,差异有统计学意义(P<0.05)。 结论 4种预防方法对7~8岁儿童第一恒磨牙防龋效果不同,窝沟封闭对龋齿预防效果最好。     

再生性牙髓治疗方法的前景

再生性牙髓治疗是基于生物学基础治疗的一种方法,目的是替换受损的部分牙髓组织或允许牙髓样组织形成以完全替代原牙髓组织。针对牙髓炎或牙髓坏死的年轻恒牙的治疗,研究者们利用口腔来源干细胞或根尖周组织的干细胞建立各种利于修复的微环境,提出了如牙髓血运重建术/干细胞归巢治疗等充满前景的新治疗技术,从而为牙髓的再生提供了大量研究资料及可选治疗手段。该文对再生性牙髓治疗方法的现状及其发展前景作一综述。