Effects of Silver-Nano Particles on Denture Base Resins

Objectives: The aim of this study was to fabricate denture base resins with long-term antibacterial effects to prevent denture stomatitis by Candida Albicans by adding the silver-nano particles inserted in zeolite(SZ) and with strengths suitable for ISO 1567 Denture Base Polymer.

Material & Methods: Two types of denture base resin were used: self-curing (Vertex SC, Dentimax) and heat-curing (Luctione 199, Dentsply/Caulk). 0, 5, 10, 15, and 20 wt% of SZ(Zeomic AJ10N, Sinanen Zeomic Co., Japan) were added to both denture base resins, respectively. The resin was cured by compression molding technique and cut into the size of 64 x 10 x 2.5 mm. The maximum flexural strengths and modulus were measured using a universal testing machine(Z020, Zwick) at a crosshead speed 5mm/min after storing in distilled water for 1, 2, and 3 weeks.

The effects of concentration of SZ and the duration of storage on the flexural strengths and modulus were evaluated by General Linear Model and Scheffe test at a=0.01.

Results: As the concentration of SZ increased, flexural strengths decreased, while flexural modulus increased significantly (P<0.01). Flexural strengths were affected only by the concentration of SZ, while flexural modulus were influenced by both the concentration of SZ and the duration of storage.

Conclusions: Denture base resin showed appropriate flexural strengths and modulus by adding SZ up to 15 wt% for heat-curing and up to 20 wt% for self-curing, according to ISO 1567. Further studies to increase the duration of storage up to 1, 2, and 6 months are being done to evaluate the effect of long-term storage on the mechanical properties. The cytotoxicity using MTT test and the antibacterial activity test using MIC and MBC are also being done.

Supported by the Korea Research Foundation Grant funded by the Korean Government (MOEHRD, Basic Research Promotion Fund) (KRF-2007-331-E00228)