L’analyse morphologique céphalométrique : que peut-elle nous enseigner ?

Cephalometric analysis is an invaluable tool for orthodontists in the diagnosis and treatment planning of their patients. This article discusses the history, development and application of the Björk cephalometric analysis. The advantages and disadvantages of the conventional analysis are discussed and the benefits of using a limited number of parameters are emphasized.     

药品"碧兰麻"商品名将更名为"必兰TM"

根据国家食品药品监督管理局药品名称管理的有关规定，法国碧兰公司生产的口腔局部麻醉剂“碧兰麻”，商品名将更名为“必兰^TM”，新货已于2004年底上市。     

正畸支抗之“惑”

与医学其他学科一样,口腔正畸学也不乏用模糊概念来取代精确测量的习惯做法,正畸支抗控制便是其中之一。随着循证医学的发展,正畸医师越来越重视临床证据的准确性,于是,以往对于正畸支抗控制的经验性描述逐渐显露出其弊端。本文根据笔者近年来对支抗的系列研究结果,阐述了最大支抗传统概念的模糊性、定量测量支抗丧失时常被忽略的问题及解决方法,并讨论了最大支抗的限度问题。     

Zinc Incorporation Improves Biological Activity of Beta-tricalcium Silicate Resin–based Cement

Introduction

Matrix metalloproteinase (MMP) inhibition may improve endodontic treatment prognosis. The purpose of this study was to determine if zinc incorporation into experimental resin cements containing bioactive fillers may modulate MMP-mediated collagen degradation of dentin.

Methods

Human dentin samples untreated and demineralized using 10% phosphoric acid or 0.5 mol/L EDTA were infiltrated with the following experimental resins: (1) unfilled resin, (2) resin with Bioglass 45S5 particles (OSspray, London, UK), (3) resin with beta-tricalcium silicate particles (βTCS), (4) resin with zinc-doped Bioglass 45S5, and (5) resin with zinc-doped βTCS particles. The specimens were stored in artificial saliva (for 24 hours, 1 week, and 4 weeks) and submitted to radioimmunoassay to quantify C-terminal telopeptide. Scanning electron microscopy analysis was also undertaken on dentin samples after 4 weeks of storage.

Results

Collagen degradation was prominent both in phosphoric acid and EDTA-treated dentin. Resin infiltration strongly reduced MMP activity in demineralized dentin. Resin containing Bioglass 45S5 particles exerted higher and stable protection of collagen. The presence of zinc in βTCS particles increases MMP inhibition. Different mineral precipitation was attained in dentin infiltrated with the resin cements containing bioactive fillers.

Conclusions

MMP degradation of dentin collagen is strongly reduced after resin infiltration of dentin. Zinc incorporation in βTCS particles exerted an additional protection against MMP-mediated collagen degradation. However, it did not occur in resin containing Bioglass 45S5 particles, probably because of the formation of phosphate-zinc compounds.     

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在中世纪的欧洲,牙痛者祈祷的对象是＂牙痛之神＂圣·阿波罗昵阿（Saint Apollonia）。据说受了牙痛之苦的人,只要向圣·阿波罗昵阿祈求立即会好。在欧洲,有关＂牙痛之神＂的故事,流传很久,直到现在还有她的彩色画像（图1）,并有多种名贵珍品。有很多有关她拥有这项特殊荣誉的传说。圣·阿波罗昵阿是一位虔诚的女基督教徒。