Effects of 405-, 532-, 650-, and 940-nm wavelengths of low-level laser therapies on orthodontic tooth movement in rats

Progress in Orthodontics

Table 2 Measurement findings of PDL distance (μm)

Group/variable		Distance of PDL		95% confidence interval for mean		p		Group/variable		Distance of PDL		95% confidence interval for mean			p
Group/variable		Mean	S.D.	Lower bound	Upper bound	p		Group/variable		Mean	S.D.	Lower bound		Upper bound	p
PDL-M	NC	0.178	0.009	0.169	0.188	0.042*		PDL-D	NC	0.136	0.015	0.120		0.152	0.007*
	PC	0.266	0.066	0.211	0.320				PC	0.225	0.048	0.185		0.266
	405 nm	0.257	0.084	0.187	0.328				405 nm	0.198	0.060	0.148		0.248
	532 nm	0.228	0.075	0.135	0.322				532 nm	0.179	0.018	0.157		0.202
	650 nm	0.244	0.051	0.197	0.291				650 nm	0.218	0.063	0.161		0.276
	940 nm	0.252	0.025	0.229	0.275				940 nm	0.153	0.029	0.127		0.180
Pairwise comparisons, p values
Group/variable	NC-PC	NC-405 nm	NC-532 nm	NC-650 nm	NC-940 nm	PC-405 nm	PC-532 nm	PC-650 nm	PC-940 nm	405–532 nm	405–650 nm	405–940 nm	532–650 nm	532–940 nm	650–940 nm
PDL-M	0.002*	0.027*	0.097	0.015*	0.003*	0.599	0.462	0.728	1.000	0.769	0.817	0.816	0.684	0.371	0.798
PDL-D	0.010*	0.038*	0.017*	0.031*	0.315	0.206	0.028*	0.954	0.015*	0.607	0.416	0.082	0.062	0.088	0.035*

PDL-M PDL distance in mesial-cervical, PDL-D PDL distance in distal-cervical, NC negative control group, PC positive control group, S.D. standard deviation
Significant degree: *p < 0.05