Table 2.
Participant characteristics.
| Caries prevalence at baseline | Caries increment | |||||
|---|---|---|---|---|---|---|
| Caries free (n = 26) | Caries (n = 37) | P- value | No (n = 38) | Yes (n = 17) | P- value | |
| Boys/Girls, % | 46.2/53.6 | 45.9/54.1 | 0.987 | 52.6/47.4 | 35.3/64.7 | 0.232 |
| Number of teeth, mean (95% CI) | 28.0 (27.6–28.4) | 27.6 (27.2–28.0) | 0.109 | 28.1 (27.6–28.5) | 27.9 (27.3–28.6) | 0.7094 |
| Caries status | ||||||
| DFS, mean (95% CI) | 0 | 5.8 (4.5–7.2) | <0.001 | 0 | 2.3 (1.5–3.1) | <0.0015 |
| DS, mean (95% CI) | 0 | 1.2 (0.7–1.6) | <0.001 | 0 | 0.53 (0.12–0.94) | <0.0015 |
| Smoking, % | 7.7 | 2.7 | 0.360 | 2.6 | 17.6 | 0.0484 |
| Swedish snuff, % | 0 | 10.8 | 0.083 | 10.5 | 11.8 | 0.8924 |
| BMI, kg/m2, mean (95% CI) | 21.4 (20.3–22.4) | 23.3 (21.8–24.9) | 0.033 | 22.3 (21.2–23.5) | 23.5 (20.5–26.6) | 0.3316 |
| Saliva flow rate, ml/min, mean (95% CI) | 1.3 (1.0–1.6) | 1.4 (1.2–1.7) | 0.523 | 1.3 (1.1–1.5) | 1.4 (1.0–1.7) | 0.6826 |
| Tooth brushing, %1 | 92.3 | 64.9 | 0.012 | 78.9 | 64.7 | 0.2636 |
| Additional fluoride, %2 | — | — | 23.7 | 58.8 | 0.0114 | |
| Sweet snacks/day, mean (95% CI) | 2.5 (1.6–3.4) | 3.8 (2.2–5.3) | 0.186 | 3.0 (2.1–4.0) | 3.1 (1.0–5.3) | 0.9266 |
| Mutans streptococci by culture, CFU/ml3 | 1.3 (0.6–2.0) | 3.1 (2.6–3.7) | <0.001 | 2.4 (1.7–3.1) | 2.8 (1.9–3.6) | 0.4896 |
| S. mutans by PCR saliva, % | 44.0 | 83.8 | 0.001 | 64.9 | 82.4 | 0.1916 |
| S. mutans by PCR tooth biofilm, % | 36.0 | 64.9 | 0.025 | 51.4 | 64.7 | 0.3596 |
Participants were 17 years old at recruitment with follow-up 2 years later. Caries was defined as DFS >0 and caries-free as DFS = 0. Caries increment was defined as DFS at follow-up - DFS at baseline. Differences in subject distributions were tested with Chi2 test among groups, and differences between group means were tested with Student’s t-test. Adjustment for sex or number of teeth did not alter the relation between groups for any variable. 1Proportion brushing twice a day or not are compared. All brushed at least 3–4 times a week. 2Additional fluoride refers to rinsing, varnish, tablets, gel treatments. Information only available in 19-year olds. All used fluoridated tooth paste. 3Mean (95% CI) for log 10 of colony forming units (CFU) per ml chewing stimulated saliva. 4Information at 19-years of age. 52-year caries increment. In adolescent with no 2-year increment, 52.2% were caries-free and 47.4 had caries at baseline, whereas those 94.1% with 2-year increment had caries at baseline. 6Data are based on information at 17-years of age.