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Antibacterial silver-containing silica glass prepared by sol-gel method
M Kawashita1, S Tsuneyama, F Miyaji
1Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Japan.
Biomaterials
|February 3, 2000
Summary
New silver-containing silica glass powders offer controlled, long-term silver ion release for dental applications. These materials exhibit excellent antibacterial properties, making them ideal for composite resins in dental restoration.
Area of Science:
- Materials Science
- Biomaterials Engineering
- Inorganic Chemistry
Background:
- Developing effective inorganic antibacterial materials with silver is crucial for medical applications.
- Existing silver-based materials often lack the desired colorlessness and long-term chemical durability for medical use.
- There is a need for materials that slowly release silver ions for sustained antibacterial action, particularly in dental restorative composites.
Purpose of the Study:
- To synthesize and characterize novel silver-containing silica glass powders.
- To investigate the effect of aluminum-to-silver (Al/Ag) atomic ratios on the glass properties and silver ion release.
- To evaluate the antibacterial efficacy of the synthesized materials for potential use in dental composite resins.
Main Methods:
- Sol-gel synthesis using tetraethyl orthosilicate, aluminum nitrate, and silver nitrate precursors.
- Controlled gelation, drying, and subsequent heat treatment at 900-1000°C.
- Characterization of glass color, silver state (colloidal vs. ionic), silver ion release kinetics, and antibacterial activity in a dental composite formulation.
Main Results:
- Colorless silica glasses containing silver ions (Ag+) were successfully produced at Al/Ag atomic ratios ≥ 1, unlike yellow glasses with metallic silver colloids (Al/Ag = 0).
- Glasses with Al/Ag ≥ 1 exhibited gradual, controlled silver ion release into water, whereas the Al/Ag = 0 composition showed rapid release.
- A composite material incorporating the Al/Ag = 1 silica glass powder demonstrated excellent antibacterial properties.
Conclusions:
- Sol-gel derived silica glass powders with Al/Ag ratios ≥ 1 are promising antibacterial materials.
- These materials offer controlled silver ion release and desirable aesthetic properties (colorless).
- The developed silver-containing silica glasses are suitable for use as fillers in composite resins for dental restoration, enhancing antibacterial performance.