Kells B E, Kennedy J G, Biagioni P A, Lamey P J
School of Dentistry, Queen's University of Belfast, Belfast, UK.
Int Endod J. 2000 Sep;33(5):442-7. doi: 10.1046/j.1365-2591.2000.00257.x.
To observe the thermographic appearance of teeth and to develop a suitable protocol for imaging teeth in human subjects using modern thermographic imaging (TI) equipment in a thermologically controlled environment.
The emissivity of enamel was investigated using an extracted incisor tooth. A total of 12 unrestored maxillary lateral incisors in six healthy patients were then imaged under rubber dam after a 20-min equilibration period and the thermographic data analysed using a dedicated software package. Recordings were made from standardized gingival and incisal sites on each tooth and the temperature gradient established for each tooth. Subsequently, a sequence of images of both maxillary central incisors in one patient was stored every 30 s during a 20-min equilibration period with and without an air-conditioning unit in operation.
For the lateral incisors there was a consistent temperature gradient (mean 1.28 degrees C) from gingival area to incisal area and there were no statistically significant differences between right and left sides for the gingival site (t = 0.34, NS) or the incisal site (t = 0.62, NS). The air-conditioning unit had a rapid and profound cooling effect. With the air-conditioning disabled there was a mean tooth surface temperature increase of 1.1 degrees C from 0 to 5 min of the equilibration period and 0.3 degree C from 15 to 20 min.
There was no significant difference in gingival or incisal temperatures between pairs of contralateral maxillary lateral incisors and a consistent temperature gradient existed from gingival to incisal areas of healthy maxillary lateral incisor teeth. The protocol described is suitable for TI of vital teeth. However, TI measured tooth surface temperature only which was extremely sensitive to air currents. A 15-min acclimatization period under rubber dam was adequate to allow stable tooth surface temperature measurement.
观察牙齿的热成像表现，并制定一个合适的方案，以便在温度可控的环境中使用现代热成像（TI）设备对人体牙齿进行成像。
使用一颗拔除的切牙研究牙釉质的发射率。然后，在六名健康患者的12颗未修复的上颌侧切牙上放置橡皮障，经过20分钟的平衡期后进行成像，并使用专用软件包分析热成像数据。在每颗牙齿的标准化牙龈和切缘部位进行记录，并为每颗牙齿建立温度梯度。随后，在一名患者的两颗上颌中切牙上，在有和没有空调运行的情况下，于20分钟的平衡期内每隔30秒存储一系列图像。
对于侧切牙，从牙龈区域到切缘区域存在一致的温度梯度（平均1.28摄氏度），牙龈部位（t = 0.34，无统计学意义）或切缘部位（t = 0.62，无统计学意义）的左右两侧之间没有统计学上的显著差异。空调机组有快速而显著的冷却效果。在空调关闭的情况下，平衡期从0到5分钟牙齿表面平均温度升高1.1摄氏度，从15到20分钟升高0.3摄氏度。
双侧上颌侧切牙之间的牙龈或切缘温度没有显著差异，健康上颌侧切牙从牙龈到切缘区域存在一致的温度梯度。所描述的方案适用于活髓牙的热成像。然而，热成像仅测量牙齿表面温度，而该温度对气流极为敏感。在橡皮障下15分钟的适应期足以进行稳定的牙齿表面温度测量。
