[Alloplastic Materials and their Propensity to Bacterial Colonisation]

Area of Science:

• Orthopaedic Surgery
• Biomaterials Science
• Microbiology

Background:

• Alloplastic materials are used for protective surface layers on orthopaedic implants.
• Joint replacement infections are a significant clinical concern.
• Biofilm formation on implant surfaces contributes to infection.

Purpose of the Study:

• To evaluate the in vitro resistance of various alloplastic materials to bacterial colonization.
• To determine the relationship between surface finish and bacterial adhesion.
• To identify optimal materials for preventing implant-associated infections.

Main Methods:

• Inoculation of 14 alloplastic material samples with common joint replacement pathogens (Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa, Enterococcus faecalis, Escherichia coli).
• Assessment of biofilm formation using spectrophotometry (AV595) after 24 hours of incubation.
• Comparison of bacterial colonization sensitivity across different material types and surface finishes.

Main Results:

• Smooth Vitalium exhibited the lowest bacterial colonization affinity (AV595, 0.368), followed by titanium (AV595, 0.459) and steel (AV595, 0.505).
• Rough titanium alloy surfaces (AV595, 0.737-1.676) and all steel surface finishes (AV595, 0.571) showed significantly increased bacterial colonization sensitivity (p < 0.05).
• Porous titanium surfaces demonstrated a significantly higher affinity for bacterial colonization.

Conclusions:

• Vitalium is the material of choice for cemented implants due to its low sensitivity to bacterial colonization.
• Titanium alloys are recommended for cementless implants.
• The osteoactive nature of porous surfaces crucial for osseointegration also presents a challenge due to increased bacterial colonization affinity on non-bone-contacting areas.