Root dentin body moisture changes caused by ascorbic acid

Objectives: To quantify in vitro the root dentin moisture (DM) when soaked in 10% ascorbic acid solution (Group A) and distilled water (Group B) for up to 14 days. Methods: Forty-four extracted human mandibular single-rooted teeth were sectioned perpendicular to the long axis at the CEJ to access the root dentin. The samples were divided into Groups A and B. Baseline (day 0) DM was measured using a digital grain moisture meter. One sample was placed in each tube, which was then filled with solution. All tubes were kept at 37 °C and 100% humidity. DM was measured after 1, 3, 7, and 14 days. The baseline DM value was used as a covariate in the generalized estimating equation (GEE) analysis to account for the difference in the baseline DM between the two groups. Results: The mean DM (%) values ± standard deviation on days 0, 1, 3, 7, and 14 were 11.4 ± 1.08, 17.1 ± 0.87, 18.2 ± 0.76, 18.4 ± 0.77, and 17.9 ± 0.90 in Group A, and 10.2 ± 0.95, 12.8 ± 0.90, 13.3 ± 0.95, 13.0 ± 0.91, and 13.2 ± 0.89 in Group B, respectively. Group A had significantly higher baseline DM than Group B (p = 0.006). After adjusting for differences in the baseline, the GEE analysis indicated that, on average, Group A had a significantly higher increase in DM than Group B, with means ± standard deviation of 4.35 ± 0.26. Conclusions: The moisture increase in the ascorbic acid group was greater than that in the distilled water group. Soaking root dentin in the unreplenished ascorbic acid solution or distilled water beyond 3 days did not further increase DM.