Antimicrobial Property of Hydrocolloid Impression Material Incorporated with Silver Nanoparticles Against Staphylococcus Aureus

¹ Orthodontic Department, Faculty of Dentistry, Mahidol University, Bangkok 10400, Thailand
² Oral Microbiology Department, Faculty of Dentistry, Mahidol University, Bangkok 10400, Thailand

Abstract

Dental impressions can easily become contaminated with patient’s blood and saliva which are capable of transmitting infectious diseases to dental personnel. The addition of antimicrobial agents into impression materials could be effective in reducing the chances of cross-infection. Silver nanoparticles have been applied in dentistry as a potent antimicrobial agent. This study aims to evaluate the in vitro antimicrobial efficacy of silver nanoparticles incorporated to irreversible hydrocolloid impression material against Staphylococcus aureus. Silver nanoparticles (AgZrPO₄, National Direct Network Company, Thailand) at concentrations of 0.25%, 0.50%, 1.00% and 1.50% w/w were added to powder of impression materials (Kromopan, Lascod, Ilaty). Impression material samples were prepared on sterile plate in accordance with manufacturer’s instruction. After setting, a 100 microliter of S. aureus ATCC6538 suspension (10⁶ cells/mL) were inoculated on the surface of the impression sample and left for 10 minutes. The amount of S. aureus on the surface was quantified using imprint technique on Mannitol Salt agar. Impression materials incorporated with AgZrPO₄ showed antimicrobial property against S. aureus (up to 95% reduction) compared with control (impression material without AgZrPO₄). Even though the mechanism of antimicrobial action was not clearly understood, AgZrPO₄ incorporated to impression material was demonstrated to possess an inhibitory effect against pathogenic bacteria. Further studies are needed to investigate physical properties of the material and the clinical usage.