Endodontic and orthodontic treatment of a cross-bite fused maxillary lateral incisor

AIM: To describe combined endodontic and orthodontic treatment of a maxillary lateral incisor fused with a supernumerary. SUMMARY: A rare case is presented in which combined endodontic and orthodontic treatment was performed on a cross-bite fused tooth. Clinical and radiographic examination showed the maxillary lateral incisor fused with a supernumerary and an impacted canine. The fused tooth required nonsurgical and surgical endodontic treatment for functional and aesthetic reasons. The root canals were dressed with calcium hydroxide for 2 months before they were obturated with thermoplasticized injectable gutta-percha. Then, the distal part of the fused tooth was removed and the mesial part of the tooth was replanted and fixed. Three months after the completion of orthodontic therapy, the impacted canine erupted between the remaining tooth and the first premolar. Recall examination, 3 years after completion of root canal treatment, showed clinical and radiographic evidence of healing. KEY LEARNING POINTS: Fusion has been described as a development anomaly characterized by the union of two adjacent teeth. Proper combined endodontic and orthodontic treatment resulted in maintaining one tooth half and solving the aesthetic and functional problem of a fused tooth.     

烧结次数对金属烤瓷修复体颜色三要素的影响

目的：研究烧结次数对金属烤瓷修复体颜色三要素的影响。方法：采用CIE1976L*a*b*色度系统，计算公式：色差△Eab*={(△L*)^2 (△b*)^2}^1/2，彩度Cab*={(a*)^2 (b*)^2}^1/2，色调角hab*=tg^-1b*/a*,L*代表明度。结果：t检验分析：金瓷烧结5次以上，颜色有明显改变，表现为明度增加；体瓷烧结3次变色，表现为明度增加，彩度增加；遮色瓷绕结3次变色，表现为色调角增大。结论：金属烤瓷修复体烧结5次以上变色，变色表现为明度增加，变色主要与体瓷层明度和彩度的增加有关；遮色瓷层烧结变色对金属烧瓷修复体颜色无明显影响。     

920例烤瓷熔附金属修复体的长期疗效观察

目的:对烤瓷熔附金属修复体的长期临床疗效进行评价。方法:追踪观察自1995年1月以来诊治的920例烤瓷熔附金属冠桥修复病例,以修复体的状况、基牙的健康情况、牙周组织的状况等几个方面作为评价指标,分析修复体的临床成功率和失败原因。结果:在观察期间发现失败病例74例,其中前牙冠36例,46个冠;后牙冠失败18例,22个冠;前牙桥失败12例,后牙桥8例,占总病例数的8.04%。其中单个冠的失败率为4.84%,固定桥失败率为8.77%。失败修复体数占总修复体数的5.39%。结论:烤瓷熔附金属修复体是目前较为理想的修复方式。为进一步提高修复成功率,在临床和技工操作当中应严格按照标准的操作程序进行操作。     

三种烤瓷熔附金属冠铬在唾液中的离子析出量分析

目的分析三种烤瓷熔附金属冠(俗称烤瓷牙)在人工唾液中铬离子的析出量。方法用镍铬合金、钴铬合金、钛铬合金,烧结成各15颗烤瓷冠,将其分别放于盛有人工唾液的密封容器中,再把容器放于37℃恒温孵育箱内,于1、2、4、8、16、32、54周末用石墨炉原子吸收分光光度计测量各样品在人工唾液中的铬离子浓度。结果三种烤瓷牙唾液样本中铬离子浓度在1～4周逐渐增加;第4周后维持较稳定水平,然后逐渐下降。结论钴铬合金组、钛铬合金组烤瓷牙铬离子析出量均小于镍铬合金组,差别有统计学意义(t=11.80,P0.01)。多重比较交互作用,NiCr组高于CoCr组,差别有统计学意义(t=12.89,P0.01),NiCr组高于TiCr组,差别有统计学意义(t=13.05,P0.01)。铬离子析出各时间点之间差别有统计学意义(t=12.48,P0.01)。     

钴铬合金烤瓷全冠的临床观察

目的:观察钴铬合金烤瓷全冠修复效果,以满足普通收入人群的口腔修复要求。方法:对120例钴铬合金烤瓷冠修复后1 a3、a进行满意度调查,观察其耐腐蚀性及牙龈状况,并与120例镍铬合金烤瓷冠对照分析。结果:钴铬合金组修复后3 a出现8件(5例)颈缘灰线(耐腐蚀性差),与对照组的52件(32例)有统计学差异,且对照组发生了17件(11例)牙龈炎。结论:钴铬合金烤瓷全冠生物相容性较好,且经济实惠。     

数字影像系统测量分析融合牙乳牙列

目的探讨Digora数字影像系统测量牙列模型的新方法并用此方法分析乳牙融合牙列的特征。方法选取AB融合牙模型和BC融合牙模型各14副。用电子游标卡尺和Digora数字影像系统分别测量牙列,并统计分析结果。结果游标卡尺测量值稍大于Digora系统测量值,且两方法所测各值均相关(r>0.80,P<0.01),比值较稳定(均值为1.05)。融合牙的牙冠宽度明显小于非融合侧两同名牙冠宽度的和(P<0.05)。AB融合牙组CC—CC和CL—CL大于BC融合组(P<0.05)。融合牙组下颌对称性系数显示牙列的非对称状,中线偏向融合侧。且下颌融合侧三角形面积小于非融合侧三角形面积(P<0.01)。结论Digora数字影像系统测量结果稳定,有利于资料保存,便于临床使用;融合牙牙列与正常牙列的差异应予以重视。     

Renal pyelic fusion with crossed solitary ureter: Case report and review of literature

Renal fusion anomalies are detected incidentally on imaging, with horseshoe kidney being the most common followed by crossed renal ectopia. We report a rare congenital anomaly of renal pyelic fusion with a solitary ureter. Both the renal units were in the normal position and location. This rare anomaly was associated with lumbar vertebral defects, neurogenic bladder, vesico‐ureteric reflux, upper tract dilatation and recurrent urinary tract infections.     

Endodermal cyst of the cervical spinal cord with associated partial fusion of the vertebrae

A case of a 43‐year‐old woman with an intradural endodermal cyst at the C4 spinal cord level is presented. The lesion manifested with progressive neck pain and weakness of lower extremities. The presumptive diagnosis of extramedullary benign cystic lesion was established after MRI examination. Coexisting partial fusion of the C5‐C6 vertebral bodies was found on X‐ray films. The patient was cured by resection of the cyst wall, performed by laminectomy. Pathological examination revealed a cyst wall lined with ciliated cuboidal cells, resembling the respiratory epithelium. Immunohistochemistry demonstrated cytokeratin and epithelial membrane antigen expression in the lining of the cyst. Endodermal cyst should be considered in the differential diagnosis of intraspinal cystic lesions, especially those associated with vertebral anomalies.     

牙龈结合上皮损伤后的超微结构的变化

目的；研究牙龈结合上皮损伤后的牙龈结合上皮在透射电镜下的组织学变化的特点以及牙龈结合上皮再附着的过程，为临床金属烤瓷修复体的修复提供参考价值。方法：16只家兔的32颗上前牙分别用金刚砂车针和手术11号尖刀破坏左侧上前牙的牙龈结合上皮，以右侧同名牙的健康未经破坏的牙龈结合上皮为对照，分别于1，2周取材，利用透射电镜观察结合上皮的组织学改变。并对两实验组进行对比观察。结果：实验组与对照组在组织学改变和超微结构变化上存在显著差异。透射电镜下可见实验组部分线粒体絮状变和空泡变，内质网脱颗粒，扩张和不完整的基膜。结论：牙体预备对牙龈结合上皮的损伤，会导致结合上皮的超微结构改变，从而影响牙龈的健康和修复体的美观。