Issa A I, Preston K P, Preston A J, Toumba K J, Duggal M S
Child Dental Health, Leeds Dental Institute, Leeds LS2 9LU, UK.
Arch Oral Biol. 2003 Aug;48(8):567-71. doi: 10.1016/s0003-9969(03)00095-5.
Clinical and in situ studies have shown that caries formation and progression is faster in primary than in permanent teeth. Ambient levels of fluoride are also known to influence the processes of carious lesion formation. The aims were, firstly to investigate the incidence of artificial sub-surface caries lesion formation in the enamel of deciduous and permanent teeth in vitro. Secondly, to compare quantitatively the mineral content and distribution of these lesions and assess the possible influence of fluoride upon the lesion parameters.
Twenty primary molars and 20 permanent premolars were randomly assigned to one of four experimental groups. Samples in each experimental group were immersed in a 0.05M lactic acid gel (6% w/v hydroxyethyl cellulose, pH 4.5) either in the absence or presence of fluoride for 7 days. Subsequently, lesion parameters of mineral loss (vol x % microm) and lesion depth (microm) were assessed by transverse microradiography and image analysis.
No significant differences existed between the lesion parameters of permanent and primary teeth (P=0.20). Irrespective of tooth type, lesion parameters were significantly reduced in samples demineralised in the presence of fluoride (P< or =0.002).
Fluoride significantly reduces the severity of sub-surface caries lesions formed in vitro and in contrary to previous studies, there were no significant differences in lesions parameters between permanent and primary teeth.
临床和原位研究表明，乳牙龋病的形成和进展比恒牙更快。已知环境氟水平也会影响龋损形成过程。本研究的目的，一是在体外研究乳牙和恒牙牙釉质中人工形成的牙本质下龋损的发生率。二是定量比较这些龋损的矿物质含量和分布，并评估氟对龋损参数的可能影响。
将20颗乳牙磨牙和20颗恒牙前磨牙随机分为四个实验组之一。每个实验组的样本分别置于不含氟或含氟的0.05M乳酸凝胶（6% w/v羟乙基纤维素，pH 4.5）中浸泡7天。随后，通过横向显微放射摄影和图像分析评估矿物质损失（体积x%微米）和龋损深度（微米）等龋损参数。
恒牙和乳牙的龋损参数之间无显著差异（P = 0.20）。无论牙齿类型如何，在含氟环境中脱矿的样本的龋损参数均显著降低（P≤0.002）。
氟显著降低了体外形成的牙本质下龋损的严重程度，与先前的研究相反，恒牙和乳牙的龋损参数无显著差异。
