LAUSR

Abstract Objectives Some non‐cavitated caries lesions (D1), the initial stage of caries, progress to cavitation. This article reports participant‐level and surface‐level D1 prevalence and changes in status of D1 lesions through different periods from age 9 to 23. Methods The Iowa Fluoride Study (IFS) participants were followed longitudinally; all permanent tooth surfaces were examined clinically for caries at ages 9, 13, 17, and 23 using standardized criteria for sound (S), questionable (D0), non‐cavitated (D1), cavitated (D2+), filled (F), or missing due to decay (M). D1 lesions at the beginning of each interval were reassessed at each follow‐up age to determine transitions (to the 5 categories or no transition). Results The sample had relatively high socioeconomic status (SES), with about 52%–55% high SES, 32–35% middle SES, and 12–13% low SES. Person‐level prevalences of D1 lesions were 23%, 38%, 60%, and 45% at ages 9, 13, 17, and 23, respectively. Surface‐level prevalences were less than 1% at ages 9 and 13, 3% at 17, and 2% at 23. Thirteen percent of D1s at age 9 progressed at 13, 18% progressed from 13 to 17, and 11% progressed from 17 to 23. The percentages regressing (to sound or D0) were 72%, 54%, and 72%, respectively. Conclusion Non‐cavitated lesions were more prevalent at age 17 than at ages 9, 13, and 23. The high rates of regression compared to progression or no change suggest that many non‐cavitated lesions do not progress to cavitated lesions and could be reversed; therefore, surgical intervention should not be the treatment of choice for incipient lesions.