Relative gene expression. All values are expressed as the average + standard deviation (n = 6). The gene expression of the TCP/HAp groups was lower compared to that of the BLANK and BMP controls initially; however, it was higher at later time points. *significant difference from the BLANK negative control group at same time point, @significant difference from the BMP positive control group at same time point, $significant difference from the TCP/HAp 7:3 group at same time point, & significant difference from the TCP/HAp 1:1 group at same time point, # significant change from its value at week 0, ^ significant change from its value at week 1.5, and % significant change from its value at week 3 (p < 0.05).