Hsu C Y, Donly K J, Drake D R, Wefel J S
Dows Institute for Dental Research, College of Dentistry, University of Iowa, Iowa City 52242, USA.
J Dent Res. 1998 Feb;77(2):418-25. doi: 10.1177/00220345980770021101.
Accumulated evidence has illustrated that secondary caries is the major reason for the failure of amalgam and resin composite restorations. The purpose of this study was to assess the cariostatic effects of aged fluoride-containing restorative materials on the formation of secondary root caries. Fifty sound human molars were selected and randomly assigned to five material groups: non-fluoride-containing amalgam (NA), fluoride-containing amalgam (FA), non-fluoride-containing composite (NC), fluoride-containing composite (FC), and glass-ionomer cement (GIC). After standardized class V cavity preparations and placement of restorations, teeth within each group were randomly divided into two subgroups, "non-aged" and "aged". The aged subgroup was immersed in an inorganic buffer solution for 2 wks before being thermocycled. After being thermocycled and subjected to four cycles of caries formation in a bacterial model system, the teeth were sectioned. Depths of outer lesions and areas of lesions on the cavity walls were measured by polarized light microscopy. The results showed that the FA and GIC groups, whether aged or not, had significantly smaller outer lesion depth than the non-fluoride-containing NA and NC groups. After aging, the FA group demonstrated significantly greater lesion depth (p = 0.0002), while the GIC group exhibited no significant changes in lesion depths. The NA group had a greater wall lesion area than the NC group, while both demonstrated no significant changes following 2 weeks of aging. The FA and GIC groups had similar inhibition areas along the cavity walls, whereas both inhibition areas increased significantly after the aging process. It is concluded that the fluoride-containing amalgam and the glass-ionomer cement, even after a two-week aging process, can still elicit a significant preventive effect on recurrent root caries in an in vitro bacterial model system.
越来越多的证据表明，继发龋是汞合金和树脂复合修复体失败的主要原因。本研究的目的是评估老化的含氟修复材料对继发根龋形成的防龋效果。选取50颗健康人磨牙，随机分为五组材料：不含氟的汞合金（NA）、含氟的汞合金（FA）、不含氟的复合材料（NC）、含氟的复合材料（FC）和玻璃离子水门汀（GIC）。在进行标准化的V类洞制备和修复体放置后，每组牙齿随机分为两个亚组，即“未老化”组和“老化”组。老化亚组在进行热循环之前，先在无机缓冲溶液中浸泡2周。在热循环并在细菌模型系统中经历四个龋形成周期后，将牙齿切片。通过偏光显微镜测量外部病变的深度和洞壁上病变的面积。结果表明，无论是否老化，FA组和GIC组的外部病变深度均显著小于不含氟的NA组和NC组。老化后，FA组的病变深度显著增加（p = 0.0002），而GIC组的病变深度无显著变化。NA组的洞壁病变面积大于NC组，而两组在老化2周后均无显著变化。FA组和GIC组沿洞壁的抑制面积相似，而在老化过程后，两组的抑制面积均显著增加。结论是，含氟汞合金和玻璃离子水门汀即使经过两周的老化过程，在体外细菌模型系统中仍能对复发性根龋产生显著的预防作用。
