Department of Preventive and Community Dentistry, Oral Health Research Institute, Indiana University School of Dentistry, Indianapolis, IN 46202, USA.
Caries Res. 2012;46(1):23-30. doi: 10.1159/000334787. Epub 2012 Jan 4.
The present study investigated the effects of fluoride (F) concentration, lesion baseline severity (ΔZ(base)) and mineral distribution on lesion progression. Artificial caries lesions were created using three protocols [methylcellulose acid gel (MeC), hydroxyethylcellulose acid gel (HEC), carboxymethylcellulose acid solution (CMC)] and with low and high ΔZ(base) groups by varying demineralization times within protocols. Subsequently, lesions were immersed in a demineralizing solution for 24 h in the presence of 0, 1, 2 or 5 ppm F. Changes in mineral distribution characteristics of caries lesions were studied using transverse microradiography. At baseline, the protocols yielded lesions with three distinctly different mineral distributions. Secondary demineralization revealed differences in F response between and within lesion types. In general, lowΔZ lesions were more responsive to F than highΔZ lesions. LowΔZ MeC lesions showed the greatest range of response among all lesions, whereas highΔZ HEC lesions were almost unaffected by F. Laminations were observed in the presence of F in all but highΔZ HEC and CMC lesions. Changes in mineral distribution effected by F were most pronounced in MeC lesions, with remineralization/mineral redeposition in the original lesion body at the expense of sound enamel beyond the original lesion in a dose-response manner. Both ΔZ(base) and lesion mineral distribution directly impact the F response and the extent of secondary demineralization of caries lesions. Further studies - in situ and on natural white spot lesions - are required to better mimic in vivo caries under laboratory conditions.
本研究调查了氟化物（F）浓度、病变基线严重程度（ΔZ(base)）和矿物质分布对病变进展的影响。使用三种方案[甲基纤维素酸凝胶（MeC）、羟乙基纤维素酸凝胶（HEC）、羧甲基纤维素酸溶液（CMC)] 和低和高 ΔZ(base) 组通过在方案内改变脱矿时间来创建人工龋损。随后，将病变在脱矿溶液中浸泡 24 小时，溶液中存在 0、1、2 或 5 ppm F。使用横向显微射线照相术研究龋损病变的矿物质分布特征变化。在基线时，方案产生了三种具有明显不同矿物质分布的病变。二次脱矿揭示了病变类型之间和内部 F 反应的差异。一般来说，低 ΔZ 病变比高 ΔZ 病变对 F 的反应更大。低 ΔZ MeC 病变在所有病变中表现出最大的反应范围，而高 ΔZ HEC 病变几乎不受 F 影响。除了高 ΔZ HEC 和 CMC 病变外，所有病变中都观察到了 F 存在时的层理。F 对矿物质分布的影响在 MeC 病变中最为明显，以再矿化/矿物质再沉积在原始病变体中为代价，在原始病变之外的健康牙釉质中以剂量反应方式进行。ΔZ(base) 和病变矿物质分布直接影响 F 反应和龋损病变的二次脱矿程度。需要进一步的原位和天然白斑病变研究，以更好地在实验室条件下模拟体内龋病。
