TABLE 1.

Summary of the ECM, mineralization, qRT-PCR and ELISA results on the different surfaces.

Results	Silicon nitride		Ti alloy		PEEK
ECM and mineralization	30 Days	60 Days	30 Days	60 Days	30 Days	60 Days
Amide I (1,637 cm−1, FTIR)	✓	✓	✓	✓	✕	✓
Amide II (1,532 cm−1, FTIR)	✓	✓	✓	✓	✕	✓
Amide III (1,228 cm−1, FTIR)	✓	✓	✓	✓	✕	✓
P-O @$\text{P}{\text{O}}_4^{3-}$ (1,030 cm−1, FTIR)	✓	✓	✓	✓	✕	✓
ACP @ (900 – 1,200 cm−1, FTIR)	✓	✓	✓	✓	✕	✓
V1 CO32− (Raman)	---	✓	---	✓	---	✕
${\text{v}}_1\text{P}{\text{O}}_4^{3-}$ and ${\text{v}}_3\text{P}{\text{O}}_4^{3-}$ (Raman		✓	---	✓	---	✕
${\text{v}}_2\text{P}{\text{O}}_4^{3-}$ and ${\text{v}}_4\text{P}{\text{O}}_4^{3-}$ (Raman)	---	✓	---	✕	---	✕
Proline and Hydroxyproline (Raman)	---	✓	---	✕	---	✕

qRT-PCR and ELISA	1 Day	3 Days	7 Days	1 Day	3 Days	7 Days	1 Day	3 Days	7 Days
Collagen I expression (fold difference)	1.38 ± 0.2	3.7 ± 0.5	0.37 ± 0.2	1.5 ± 0.5	2.7 ± 0.4	1.2 ± 0.3	1.0 ± 0.4	1.8 ± 0.5	0.24 ± 0.1
RUNX 2 expression (fold difference)	2.2 ± 0.4	2.8 ± 0.7	2.7 ± 0.5	2.9 ± 0.4	2.6 ± 0.5	2.4 ± 0.6	1.3 ± 0.3	1.13 ± 0.4	1.0 ± 0.5
Osterix expression (fold difference)	1.4 ± 0.35	2.2 ± 0.33	1.7 ± 0.5	1.04 ± 0.3	2.6 ± 0.5	2.11 ± 0.4	1.0 ± 0.3	0.9 ± 0.2	1.2 ± 0.6
Osteocalcin concentration (ng/ml)	0.34	0.43	1.48	0.35	0.45	1.5	0.33	0.32	0.69