Table 2.

The bone formation area in different groups at different time

	2 weeks	4 weeks	8 weeks	12 weeks	24 weeks
Group A	0 ± 0	0 ± 0	0 ± 0	0 ± 0	0 ± 0
Group B	7.68 ± 2.59	9.57 ± 1.55	39.88 ± 5.65	48.30 ± 7.78	71.92 ± 6.39
Group C	3.15 ± 1.94*	4.07 ± 1.12*	4.88 ± 0.12*	7.37 ± 3.42*	34.66 ± 4.41*
Group D	3.36 ± 1.78#	5.70 ± 1.27#	26.56 ± 5.21#□	42.88 ± 8.59□	67.81 ± 3.57□
F	8.661	27.324	93.778	60.871	30.145
P value	< 0.05	< 0.05	< 0.05	< 0.05	< 0.05

Data are expressed as mean ± standard deviation. Group A had no difference in each time point and was not included in the statistical analysis. *P value < 0.05, group C compared with group B. ^#P value < 0.05, group D compared with group B. □P value < 0.05, group C compared with group D