Table 1. Associations between various factors and cracked teeth in 2009 and 2019.
| Variable | Subgroup | Year: 2009 ( N = 68) |
p -Value (1) | Year: 2019 ( N = 185) |
p -Value (2) | p -Value (3) |
|---|---|---|---|---|---|---|
| Note: Data were expressed as number and percentage. Distribution of sample ratios among each subgroup within the data from 2009 or 2019 was analyzed using the Chi-square test, yielding p -value (1) and p -value (2). To compare sample ratios between the data from 2009 and 2019, the two-sample proportion test was performed, yielding p -value (3). A p -value <0.05 was considered to indicate statistical significance. | ||||||
| Sample no. | N = 68 | N = 185 | ||||
| Location of tooth | <0.001 | <0.001 | ||||
| Mandibular first molar | 23 (33.8) | 42 (22.7) | 0.103 | |||
| Mandibular first premolar | 2 (2.9) | 2 (1.1) | 0.629 | |||
| Mandibular second molar | 5 (7.4) | 52 (28.1) | <0.001 | |||
| Mandibular second premolar | 1 (1.5) | 5 (2.7) | 0.916 | |||
| Maxillary first molar | 12 (17.6) | 38 (20.5) | 0.738 | |||
| Maxillary first premolar | 10 (14.7) | 6 (3.2) | 0.002 | |||
| Maxillary second molar | 7 (10.3) | 31 (16.8) | 0.281 | |||
| Maxillary second premolar | 8 (11.8) | 9 (4.9) | 0.097 | |||
| Age, years | <0.001 | <0.001 | ||||
| 20–29 | 12 (17.6) | 4 (2.2) | <0.001 | |||
| 30–39 | 5 (7.4) | 27 (14.6) | 0.186 | |||
| 40–49 | 11 (16.2) | 40 (21.6) | 0.435 | |||
| 50–59 | 21 (30.9) | 51 (27.6) | 0.718 | |||
| 60–69 | 18 (26.5) | 41 (22.2) | 0.582 | |||
| ≥70 | 1 (1.5) | 22 (11.9) | 0.021 | |||
| Sex | 0.628 | 0.023 | ||||
| F | 36 (52.9) | 108 (58.4) | 0.528 | |||
| M | 32 (47.1) | 77 (41.6) | 0.528 | |||
| Type of restorative material | <0.001 | <0.001 | ||||
| Cl 1 Amalgam. | 8 (11.8) | 19 (10.3) | 0.911 | |||
| Cl 1 Ceramic inlay | 0 (0) | 3 (1.6) | 0.688 | |||
| Cl 1 Gold inlay | 11 (16.2) | 44 (23.8) | 0.259 | |||
| Cl 1 Resin | 4 (5.9) | 16 (8.6) | 0.645 | |||
| Cl 2 Amalgam. | 4 (5.9) | 2 (1.1) | 0.079 | |||
| Cl 2 Ceramic inlay | 0 (0) | 2 (1.1) | 0.952 | |||
| Cl 2 Gold inlay | 3 (4.4) | 15 (8.1) | 0.460 | |||
| Crown | 2 (2.9) | 11 (5.9) | 0.523 | |||
| No restoration | 35 (51.5) | 68 (36.8) | 0.049 | |||
| Temporary filling | 1 (1.5) | 5 (2.7) | 0.916 | |||
| Cervical abrasion | <0.001 | <0.001 | ||||
| Present | 3 (4.4) | 15 (8.1) | 0.460 | |||
| Absent | 65 (95.6) | 170 (91.9) | 0.460 | |||
| Caries | 0.015 | <0.001 | ||||
| Present | 24 (35.3) | 42 (22.7) | 0.063 | |||
| Absent | 44 (64.7) | 143 (77.3) | 0.063 | |||
| Crack line | 0.002 | <0.001 | ||||
| 1 | 21 (30.9) | 131 (70.8) | <0.001 | |||
| >2 | 47 (69.1) | 54 (29.2) | <0.001 | |||