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Variations in mean biaxial flexural strength were explained by the balance between the depth of toughening mechanisms (phase transformation and FDS) and subsurface damage. AAF and GP groups were the most efficient surface adjustments in promoting the highest mean biaxial flexural strength.

Silver nanoparticles (AgNPs) have been proposed to combat oral infection due to their efficient ionic silver (Ag +) release. However, concentrations required for antimicrobial efficacy may not be therapeutically viable. In this work, platinum-doped silver nanoparticles (Pt-AgNPs) were explored to evaluate their potential for enhanced Ag + release, which could lead to enhanced antimicrobial efficacy against S. aureus, P. aeruginosa, and E. coli. AgNPs doped with 0.5, 1, and 2 mol% platinum (Pt 0.5-AgNPs, Pt 1-AgNPs, and Pt 2-AgNPs) were synthesized by a chemical reduction method. Transmission electron microscopy revealed mixed morphologies of spherical, oval, and ribbon-like nanostructures. Surface-enhanced Raman scattering revealed that the surface of Pt-AgNPs was covered with up to 93% Pt. The amount of Ag + released increased 16.3-fold for Pt 2-AgNPs, compared to AgNPs. The initial lag phase in bacterial growth curve was prolonged for Pt-AgNPs. This is consistent with a Ag + release profile that exhibited an initial burst followed by sustained release. Doping AgNPs with platinum significantly increased the antimicrobial efficacy against all species. Pt 2-AgNPs exhibited the lowest minimum inhibitory concentrations, followed by Pt 1-AgNPs, Pt 0.5-AgNPs, and AgNPs, respectively. Doping AgNPs with a small amount of platinum promoted the release of Ag + , based on the sacrificial anodic effect, and subsequently enhanced their antimicrobial efficacy.

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, who have always been there for me and understood me when I was down. You know who I am. I would like to acknowledge Thai Royal scholarship that allowed me to study the Master degree in Oral Science at The University of Iowa. In addition, I would like to thank the American College of Prosthodontics Education Foundation for their financial support for this project. Lastly and the most importantly, I would like to thank all my family who have always supported me and been there for me. Your unconditional love and care are my power that strengthens me to move forward.