Characterization of polymethylmethacrylate microspheres loaded with silver and doxycycline for dental materials applications

Objectives The manufacturing of polymethylmethacrylate(PMMA) microspheres loaded with doxycycline(DOX) and/or silver sulfate(Ag₂SO₄) to be incorporated into glass ionomer cement(GIC). Methods PMMA microspheres were manufactured with Ag₂SO₄(1-5%) and/or DOX(5-15%). Particle size, encapsulation efficiency and drug release were measured by light microscope, ICP, and HPLC. Microspheres were added to a dental GIC(20%w/w). Drug release and DTS were investigated. Minimum inhibitory concentration and antibacterial effects of PMMA microspheres into GIC materials were tested. Results The median diameter of 50 µm was obtained for microspheres. DOX was encapsulated at an efficiency of 8.3% using a theoretical loading of 15%DOX + 5%Ag₂SO₄. The Ag₂SO₄ encapsulation efficiency was 0.63% using a theoretical loading of 5%AgSO₄. All groups showed burst release within the first day and continued released up to 15 days, with 60-83% of DOX and approximately 30% of silver. For GIC, approximately 15% of DOX and 0.18% of silver were released in a 7-day period. Microbiological results showed an antimicrobial effect against S. mutans when the lead formulation of microspheres was added. The DTS was reduced by the inclusion of microspheres. Significance PMMA microspheres containing DOX and Ag₂SO₄ offer a sustained antimicrobial activity for dental applications and promising potential for the biomedical field.