Table 1.

Comparison of the number of bacteria in different groups with the same thickness.

Thickness (mm)	Group	Mean	S.D	Average bacterial reduction (%)	P-value
0.3	Er, Cr:YSGG laser	216900.00	103530.40	44	0.285
	445 nm diode laser	205000.00	208595.90	48
	Er, Cr:YSGG +445 nm diode laser	158111.11	135794.37	60
	Control	390000.00	176776.69
0.5	Er, Cr:YSGG laser	463500.00	4513383.07	28	0.096
	445 nm diode laser	514100.00	347925.10	20
	Er, Cr:YSGG +445 nm diode laser	245800.00	189973.56	62
	Control	637000.00	331911.13
1.0	Er, Cr:YSGG laser	457600.00	224649.94	34	<0.001
	445 nm diode laser	969000.00	623270.05	0
	Er, Cr:YSGG +445 nm diode laser	237300.00	158675.10	66
	Control	691142.85	139632.16

 ^∗Kruskal-Wallis test.