TABLE 5: Significance of correlation between grades of fluorosis and DMFT for different age groups
| S. no | Age group | t cal | t tab | P value | ||||
| 1 | Group I (8-9 years) | –23.5931** | P << 0.05 | |||||
| P << 0.05 | ||||||||
| 2 | Group II (9-10 years) | –19.29 | t (0.05) = 1.962 | Significant | ||||
| 3 | Group III (10-11 years) | –10.38 | t (0.01) = 2.58 | Significant | ||||
| 4 | Group IV (11-12 years) | –16.8053 | Significant | |||||
| 5 | Group V (12-13 years) | –9.3444* | P << 0.05 | |||||
| P << 0.05 | ||||||||
| 6 | Group VI (13-14 years) | –12.9369 | Significant | |||||
| ** = Highly significant, * = Significant, at 5% and 1% level of significance | ||||||||