http://www.startdental.com/blog/u/gxj19722003/archives/2008/112.html

这篇是06年3月份读外文文献的读书笔记，觉得在临床上还是比较常见这种问题，国内好像还没有相关的介绍，就整理了一下，供大家参考。

牙颈部burnout 现象：x 线下，牙颈部近中或远中因投照技术问题造成低密度影像，位于釉质和牙槽脊顶之间，称牙颈部burnout 现象（cervical burnout），为正常表现，勿与根面龋混淆。

下面附上原文和图：

http://www.startdental.com/blog/UploadFiles/2008-9/272016957822.jpg现象" TITLE="牙颈部"burnout" 现象" />

Cervical burnout, a radiolucent artifact seen on dental radiographs,may also be confused with dental caries. Cervical burnout appears as a collar or wedge-shaped radiolucency on the mesial and distal root surfaces near the CEJ of a tooth (see red arrows).When seen as a radiolucent collar, cervical burnout may be confused with root caries. This radiolucent artifact is seen because of the difference in densities of adjacent tissues. The tissue density at the cervical region of the tooth is less dense than the regions above and below it; above the neck of the tooth,enamel covers the crown, and below the neck of the tooth, bone covers the roots.

http://www.startdental.com/blog/UploadFiles/2008-9/272019653515.jpg现象" TITLE="牙颈部"burnout" 现象" />

http://www.startdental.com/blog/UploadFiles/2008-9/272020809301.jpg现象" TITLE="牙颈部"burnout" 现象" />

 Cervical burnout can also appear as an ill-defined wedge-shaped radiolucency on the mesial or distal root surfaces near the CEJ of posterior teeth. This wedge-shaped radiolucency is seen because of the anatomic root concavities found in this area. CERVICAL BURNOUT - Purple arrows point to examples of cervical burnout. Cervical burnout appears as a radiolucent artifact seen on a dental radiograph, and may be confused with dental caries. Cervical burnout appears as a collar or wedge-shaped radiolucency on the mesial and distal root surfaces near the CEJ of a tooth and may be confused with root caries.

NOTE: No carious areas can be seen on the radiograph.