Table 3.

Surface chemistry composition of zirconia blocks (in atomic percentage) for each group.

Elements	Groups
	Control	NTP	Si	NTP + Si	Pr	NTP + Pr
C	21.10	14.56	71.14	79.33	81.19	82.72
O	49.90	55.96	16.97	12.02	17.61	16.77
Zr	20.25	20.76	0.17	0.15	0.37	0.00
Si	1.42	2.45	9.92	7.00	0.52	0.33
P	0.02	0.02	0.12	0.21	0.23	0.10
Y	7.25	6.24	1.39	1.07	0.07	0.06