Shwartz M, Gröndahl H G, Pliskin J S, Boffa J
Arch Oral Biol. 1984;29(7):529-36. doi: 10.1016/0003-9969(84)90074-8.
Four to ten years of serial bite-wing radiographs from over 700 children from five groups, three in Sweden and two in the U.S., were interpreted. By analysing changes in the depth of unfilled lesions over time, the mean time and probability distribution for the time a lesion remains in both the outer half and inner half of the enamel were estimated. The procedure incorporated information on filled lesions and non-progressing lesions and thus minimized bias that results in overestimation of the progression rate. In primary teeth, in both the U.S. and Swedish groups, it took on average 12 months for a lesion to progress through the outer half of the enamel and on average 10-12 months for a lesion to progress through the inner half. In newly-erupted first permanent molars, it took 21-23 months for a lesion to progress through the outer half of the enamel and between 19 (U.S. data) and 28 months (Swedish data) for progression through the inner half. In older adolescents in the two Swedish groups, progression was slower: 38-41 months through the outer-half and 47-56 months through the inner-half. In older U.S. adolescents, progression appeared to be more rapid: 16 months through the outer half of the enamel and 27 months through the inner half. The duration of time a lesion remains in different halves of the enamel could be approximated by a piecewise exponential or exponential probability distribution, which exhibits extreme variability. Assuming duration in each half of the enamel follows an exponential distribution with a mean of 2 yr, about 10 per cent of new lesions will progress through the enamel in one year and 25 per cent in two years. However, over 40 per cent of the lesions will not have progressed in 4 yr. There were no consistent differences in the rate of progression by sex, between upper and lower dentitions, for premolars versus molars, or between high and low-risk individuals.
对来自五个组（瑞典的三个组和美国的两个组）的700多名儿童的连续4至10年的咬合翼片进行了分析。通过分析未填充病变深度随时间的变化，估计了病变在釉质外半层和内半层停留的平均时间和概率分布。该程序纳入了填充病变和非进展性病变的信息，从而将导致进展率高估的偏差降至最低。在美国和瑞典的组中，乳牙的病变平均需要12个月才能穿过釉质的外半层，平均需要10至12个月才能穿过内半层。在新萌出的第一恒磨牙中，病变穿过釉质外半层需要21至23个月，穿过内半层需要19个月（美国数据）至28个月（瑞典数据）。在瑞典的两个组中，年龄较大的青少年进展较慢：穿过外半层需要38至41个月，穿过内半层需要47至56个月。在美国年龄较大的青少年中，进展似乎更快：穿过釉质外半层需要16个月，穿过内半层需要27个月。病变在釉质不同半层停留的时间可以用分段指数或指数概率分布来近似，这表现出极大的变异性。假设在釉质每半层的停留时间遵循均值为2年的指数分布，约10%的新病变将在一年内穿过釉质，25%将在两年内穿过。然而，超过40%的病变在4年内不会进展。在按性别、上下牙列、前磨牙与磨牙或高风险与低风险个体划分的进展率方面，没有一致的差异。
