Table 2. Number of subjects according to smoking status by confounding variables.
| Variables and criteria | Non-smoker | Former smoker | Current smoker | Total |
| Frequency of daily tooth brushing | ||||
| More than twice | 1822 (69.9) | 325 (12.5) | 459 (17.6) | 2606 (100) |
| Less than once | 680 (48.8) | 250 (17.9) | 463 (33.2) | 1393 (100) |
| Body mass index (Kg/m2) | ||||
| −24.9 | 1793 (62.5) | 393 (13.7) | 684 (23.8) | 2870 (100) |
| 25.0+ | 709 (62.6) | 182 (16.1) | 238 (21.1) | 1129 (100) |
| Status of alcohol consumption | ||||
| Never | 2172 (80.0) | 200 (7.4) | 343 (12.6) | 2715 (100) |
| Former | 45 (23.0) | 82 (41.8) | 69 (35.2) | 196 (100) |
| Current | 285 (26.2) | 293 (26.9) | 510 (46.9) | 1088 (100) |
| Intake of vitamin C (mg/day) | ||||
| 100+ | 1680 (65.1) | 392 (15.2) | 507 (19.7) | 2579 (100) |
| <100 | 822 (57.9) | 183 (12.9) | 415 (29.2) | 1420 (100) |
| Intake of vitamin E (mg/day) | ||||
| 10+ (males) or 8+ (females) | 1377 (67.6) | 261 (12.8) | 399 (19.6) | 2037 (100) |
| <10 (males) or <8 (females) | 1125 (57.3) | 314 (16.0) | 523 (26.7) | 1962 (100) |
Parcentages in parentheses