Table 1.
Primary endpoint: Impedance measurement in test and control teeth (N = 21, split-mouth design, 122 observations in 2 sites or teeth at 3 time points).
| Observed values | Estimated values (adjusted for baseline values) | |||||
|---|---|---|---|---|---|---|
| Test Group | Control Group | Test Group | Control Group | Treatment effect | ||
| Mean ± SE | Mean ± SE | Difference (95% CI) | p value | |||
| Baseline | ||||||
| Mean ± SD | 46.7 ± 16.9 | 42.0 ± 15.7 | ||||
| Median (IQR) | 50 (44–52) | 47 (35–50) | ||||
| Day 45 | ||||||
| Mean ± SD | 21.1 ± 23.2 | 35.0 ± 23.4 | 20.7 ± 5.1 | 35.4 ± 5.1 | −14.7 (−22.8 – −6.6) | 0.001 |
| Median (IQR) | 14 (7–23) | 32 (17–51) | ||||
| Day 90 | ||||||
| Mean ± SD | 18.4 ± 22.3 | 29.5 ± 25.0 | 18.2 ± 5.0 | 29.8 ± 5.0 | −11.7 (−19.4 – −3.9) | 0.005 |
| Median (IQR) | 10 (7–21) | 19 (9–47) | ||||
| Day 180 | ||||||
| Mean ± SD | 19.7 ± 24.2 | 33.7 ± 25.5 | 19.4 ± 5.4 | 34.0 ± 5.4 | −14.6 (−24.5 – −4.8) | 0.007 |
| Median (IQR) | 10 (5–27) | 35 (10–49) | ||||
| Baseline vs | ||||||
| Day 45 | ||||||
| Mean ± SD | 25.5 ± 23.3 | 7.0 ± 21.7 | ||||
| Median (IQR) | 30 (18–43) | 15 (−1–21) | ||||
| Day 90 | ||||||
| Mean ± SD | 28.1 ± 25.1 | 12.2 ± 22.9 | ||||
| Median (IQR) | 36 (16–43) | 14 (−4–32) | ||||
| Day 180 | ||||||
| Mean ± SD | 26.8 ± 28.0 | 8.0 ± 27.4 | ||||
| Median (IQR) | 36 (17–45) | 10 (1–28) | ||||
According to the manufacturer impedance values correspond to the following:
Sound: 0 = sound; 1–20 = Sound enamel, caries at the very outer enamel; Enamel caries 21–30 = caries in the outer 1/3 of the enamel; 31–50 = caries in the middle 1/3 of the enamel; 51–90 = caries in the inner 1/3 of the enamel; 91–99 = caries at the dentine enamel junction; 100 = established dentine caries.
Abbreviation: CI, confidence interval; IQR, interquartile range; SD, standard deviation; SE, standard error of the mean.