Double-layered acrylic resin denture base with nanoparticle additions: An in vitro study

Area of Science:

• Dental Materials Science
• Nanotechnology in Dentistry
• Biomaterials Engineering

Background:

• The impact of antifungal nanoparticles on the physical and esthetic properties of denture base nanocomposites remains largely uninvestigated.
• Understanding these effects is crucial for developing improved denture materials with enhanced antifungal capabilities.

Purpose of the Study:

• To evaluate the influence of incorporating zirconium dioxide nanoparticles (ZrO2NPs) and silver nanoparticles (AgNPs) into acrylic resin denture base materials.
• To assess the effects of a novel double-layer packing method on the properties of these nanocomposites.

Main Methods:

• Acrylic resin specimens were fabricated with varying concentrations (0.5-1.5%) of ZrO2NPs and AgNPs.
• Specimens were prepared using a conventional one-step or a novel two-step (double-layer) packing technique.
• Evaluated properties included flexural strength (FS), translucency, surface roughness (Ra), and Candida albicans adhesion via microbial assays.

Main Results:

• Both ZrO2NPs and AgNPs significantly reduced Candida albicans adhesion in both one-layer and two-layer specimens.
• ZrO2NPs notably increased FS in both packing methods, while AgNPs decreased FS in the one-layer method.
• Surface roughness was unaffected by ZrO2NPs and minimally affected by low AgNP concentrations, but increased with higher AgNP concentrations.
• Translucency was reduced by both nanoparticles, with ZrO2NPs having a lesser impact in the two-layer technique.

Conclusions:

• The double-layer technique with ZrO2NPs effectively reduced Candida adhesion and enhanced FS without compromising surface roughness.
• AgNPs also reduced Candida adhesion but negatively affected FS and increased surface roughness.
• Both nanoparticles impacted translucency, with specific concentrations and techniques influencing the outcome.