Dijkman G E, de Vries J, Arends J
State University of Groningen, The Netherlands.
Caries Res. 1994;28(2):87-93. doi: 10.1159/000261627.
Composite restorations are prone to develop secondary caries if a gap exists between tissue and restoration. The aim of this article was to quantify the effects of a fluoridating and non-F composite on secondary dentine caries in vitro as a function of time. The mineral loss in dentine was assessed in an artificial gap of 200 microns width at the composite/dentine interface; the samples were demineralised in a carboxymethylcellulose gel (pH = 5, 37 degrees C) for 8 weeks. Once a week the mineral content of the samples was determined using non-destructive wavelength-independent microradiography (WIM). After 8 weeks transversal microradiography (TMR) was done on the samples to investigate the mineral distribution of the dentine lesions. The WIM results show that the fluoride-releasing composite decreased the dentine demineralisation statistically significantly with respect of the non-F control by approximately 45%. The mineral loss values are found to be strictly proportional to time; the demineralisation reduction is expected to continue over extended periods of clinical relevance. The TMR results show that the fluoridating composite reduced the mineral loss values significantly with respect to the non-F control by approximately 55%, but had a negligible effect on the lesion depth values. This study indicates that WIM is an accurate and reliable technique to measure in vitro secondary dentine caries next to a composite restoration as a function of time.
如果组织与修复体之间存在间隙，复合树脂修复体容易发生继发龋。本文的目的是量化含氟和不含氟复合树脂对体外继发牙本质龋的影响，并将其作为时间的函数进行研究。在复合树脂/牙本质界面200微米宽的人工间隙中评估牙本质中的矿物质流失；将样本在羧甲基纤维素凝胶（pH = 5，37摄氏度）中脱矿8周。每周使用无损波长无关微射线照相术（WIM）测定样本的矿物质含量。8周后，对样本进行横向微射线照相术（TMR），以研究牙本质病变的矿物质分布。WIM结果表明，与不含氟的对照组相比，释放氟的复合树脂在统计学上显著降低了牙本质脱矿，降低幅度约为45%。发现矿物质流失值与时间严格成正比；预计在更长的临床相关时间段内，脱矿减少仍将持续。TMR结果表明，与不含氟的对照组相比，含氟复合树脂显著降低了矿物质流失值，降低幅度约为55%，但对病变深度值的影响可忽略不计。本研究表明，WIM是一种准确可靠的技术，可用于测量复合树脂修复体旁体外继发牙本质龋随时间的变化情况。
