Mechanical Properties Of Modified SoftLiner Materials Incorporating Antibacterial Polyethylenimine Nanoparticles

Objectives: Colonization of denture soft lining materials by various oral microorganisms can result in clinical problems, and deterioration of the material. Thus, soft lining materials encompassing antibacterial properties are favorable. To this aim, we previously showed that crosslinked quaternary ammonium polyethylenimine (QPEI) nanoparticles incorporated at 1 and 2% w/w in soft liner materials modify these materials to possess antibacterial properties. Regrettably, conventionally used soft lining disinfecting protocols compromise their physical and mechanical properties. In the present study physical and mechanical properties of modified soft lining material incorporating antibacterial polyethylenimine nanoparticles have been investigated Methods: Mechanical properties of soft lining material incorporating 0, 1 or 2% (QPEI) nanoparticles were tested. Standard samples (80mm*6mm*2mm) were tested (n=15 for each test group) using a loading machine. Results: No change in the material stiffness was recorded after incorporating 1 or 2% QPEI nanoparticles when compared to the non-modified soft lining material. No significant difference was observed in strength in the 1% group when compared to the control group. In the 2% group a significant decrease in strength was recorded, although recorded values were still within the standard range for soft lining materials (P<0.001). Conclusion: Modification of soft lining material to possess antibacterial properties using QPEI nanoparticle does not compromise it mechanical properties.