Table 5.

Comparison of mean gingival index scores between three groups at different time intervals using Kruskal-Wallis test

Time	Group	n	Mean±SD	χ 2	P
Before	Group 1	30	0.40±0.17	17.504	0.001*
	Group 2	30	0.58±0.16
	Group 3	30	0.53±0.17
7 days	Group 1	30	0.42±0.17	45.335	0.001*
	Group 2	30	0.75±0.19
	Group 3	30	0.79±0.17
30 days	Group 1	30	0.41±0.18	58.629	0.001*
	Group 2	30	1.07±0.32
	Group 3	30	1.06±0.38
6 months	Group 1	30	0.40±0.17	63.873	0.001*
	Group 2	30	1.13±0.31
	Group 3	30	1.15±0.36

*Statistically significant at P<0.05. Group 1 – Control; Group 2 – Nonfluoridated group; Group 3 – Fluoridated group; SD – Standard deviation; n – Number of subjects; P – Probability value