Gostanian Harout V, Shey Zia, Kasinathan Chinnaswamy, Caceda Jorge, Janal Malvin N
Department of Pediatric Dentistry, New Jersey Dental School, The University of Medicine and Dentistry of New Jersey, Newark, USA.
Pediatr Dent. 2006 Sep-Oct;28(5):445-50.
The purposes of this study were to: (1) evaluate the ability of a laser fluorescence (LF) unit to detect simulated caries under pit and fissure sealants; (2) determine the effect of an opacifying agent in sealants on LF values; and (3) determine interexaminer reproducibility values of the unit in a highly controlled, laboratory setting. Sealant characteristics specifically considered were: (1) filler content; (2) opacity; and (3) intrinsic fluorescence.
Three sealants were used in this study: 2 unfilled and 1 filled. To evaluate the effect of an opacifying agent, titanium dioxide powder was added to both filled and unfilled sealants. 0.5-mm thick sealant discs were prepared for all samples. The sealant discs were individually placed on top of 3 wells filled with varying amounts of protoporphyrin IX, a fluorescent material that mimicked dental caries. A total of 270 readings were made through the different sealant discs to evaluate signal attenuation of the laser fluorescence unit.
Clear sealants, without an added opacifying agent, attenuated LF readings. At baseline protoporphyrin IX levels yielding DIAGNOdent readouts of 20 and 60, there was a significant difference in the LF readings between the baseline protoporphyrin (uncovered) and with sealant disc covered in all 3 sealant types (P<.001). Furthermore, the filled sealant attenuated LF signals significantly more than the unfilled sealant (P<.001). Sealants with titanium dioxide added had variable levels of intrinsic fluorescence. Titanium dioxide added to the sealants also had a profound effect on fluorescence transmission of the underlying simulated caries. As the concentration of titanium dioxide approached 0.5%, the fluorescence signal was almost fully attenuated.
Clinical detection of caries under dental sealants with the use of laser fluorescence units is unreliable and not recommended due to a high likelihood of inaccurate readings caused by: (1) intrinsic fluorescence of sealant material; and (2) attenuation of fluorescence signals by the sealant.
本研究的目的是：（1）评估激光荧光（LF）装置检测窝沟封闭剂下方模拟龋的能力；（2）确定封闭剂中遮光剂对LF值的影响；（3）在高度可控的实验室环境中确定该装置在不同检查者之间的重复性数值。具体考虑的封闭剂特性为：（1）填料含量；（2）不透明度；（3）固有荧光。
本研究使用了三种封闭剂：2种无填料的和1种有填料的。为评估遮光剂的效果，将二氧化钛粉末添加到有填料和无填料的封闭剂中。为所有样本制备了0.5毫米厚的封闭剂圆盘。将封闭剂圆盘分别放置在3个装有不同量原卟啉IX的孔的顶部，原卟啉IX是一种模拟龋齿的荧光物质。通过不同的封闭剂圆盘总共进行了270次读数，以评估激光荧光装置的信号衰减。
未添加遮光剂的透明封闭剂会使LF读数衰减。在基线原卟啉IX水平产生诊断仪读数为20和60时，在所有3种封闭剂类型中，基线原卟啉（未覆盖）和覆盖封闭剂圆盘时的LF读数存在显著差异（P<0.001）。此外，有填料的封闭剂比无填料的封闭剂对LF信号的衰减明显更多（P<0.001）。添加了二氧化钛的封闭剂具有不同水平的固有荧光。添加到封闭剂中的二氧化钛对下层模拟龋齿的荧光透射也有深远影响。随着二氧化钛浓度接近0.5%，荧光信号几乎完全衰减。
由于存在以下原因导致读数不准确的可能性很高，因此不建议使用激光荧光装置对牙用封闭剂下方的龋齿进行临床检测：（1）封闭剂材料的固有荧光；（2）封闭剂对荧光信号的衰减。
