Decreased bacteria activity on Si₃N₄ surfaces compared with PEEK or titanium

Figures & data

Table 1 Comparative properties of medical grades of Si₃N₄, ASTM³⁵ grade 4 Ti, and PEEK

Property	Units	Si3N4	Ti-ASTM grade 4	PEEK optima^®
Composition	NA	Si3N4, Y2O3, AI2O3	Chemically pure	Chemically pure
Surface composition	NA	SiNH2 and SiOH	TiO2 layer	–OH groups
Surface roughness (AFM)	nm	10.1*, 25.3**	3.06	1
Isoelectric point	NA	9	~4.5	~4.5
Surface charge at pH = 7	NA	Positive	Negative	Negative
Sessile water drop wetting angle	Degrees	39	76	95

Notes:

* Polished surface;

** as-fired surface.

Figure 1 Scanning electron microscopy surface microstructures of PEEK Optima^®, Ti, and Si₃N₄: (A1) PEEK 1000×; (A2) PEEK 5000×; (B1) Ti 1000×; (B2) Ti 5000×; (C1) Si₃N₄ 1000×; (C2) Si₃N₄ 5000×.

Abbreviation: PEEK, poly-ether-ether-ketone.

Figure 2 Scanning electron microscopy surface microstructure of polished and as-fired Si₃N₄: (A) polished surface 20,000×; (B) as-fired surface 20,000×.

Figure 3 Biofilm formation: (A) Staphylococcus epidermidis, (B) S. aureus, (C) Pseudomonas aeruginosa, (D) Escherichia coli, (E) Enterococcus.

Note: Dashed lines represent confidence intervals at P < 0.05.

Abbreviations: SN, Si₃N₄; PEEK, poly-ether-ether-ketone.

Figure 4 Count of live bacteria: (A) Staphylococcus epidermidis, (B) S. aureus, (C) Pseudomonas aeruginosa, (D) Escherichia coli, (E) Enterococcus.

Note: Dashed lines represent confidence intervals at P < 0.05.

Abbreviations: SN, Si₃N₄; PEEK, poly-ether-ether-ketone.

Figure 5 Protein adsorption: (A) 20 minutes, (B) 60 minutes, (C) 240 minutes.

Notes: *P < 0.01 compared with all others; **P < 0.05 compared with PEEK.

Abbreviations: Arb, arbitrary; SN, Si₃N₄; PEEK, poly-ether-ether-ketone.

PuckettSDTaylorERaimondoTWebsterTJThe relationship between the nanostructure of titanium surfaces and bacterial attachmentBiomaterials201031470671319879645

 PubMed Web of Science ®Google Scholar