Table 3: Comparison of preintervention and postintervention mean oral hygiene index-simplified scores in the three groups

		Oral hygiene index-simplified
Group code		Before intervention (SD)		After intervention (SD)		Statistical inference
Group 1		3.19 (0.8)		3.11 (0.95)		t = 2.672 df = 36 p < 0.011
Group 2		3.09 (0.83)		0.82 (0.41)		t = 16.038 df = 39 p < 0.001
Group 3		3.11 (0.84)		2.85 (0.97)		t = 3.717 df = 39 p < 0.001
Overall		3.13 (0.82)		2.26 (1.39)		t = 9.302 df = 115 p < 0.001

SD: Standard deviation