To incorporate Ag-doped TiO2 nanoparticles into an orthodontic bonding resin and assess the optimal concentrations needed to provide suitable antimicrobial activity against a variety of oral bacteria. This novel bonding material would provide long-term antimicrobial protection for the duration of orthodontic treatment and help to prevent the occurrence white spot lesions (WSL) under visible light.
Method:
A laboratory investigation into the loading of TiO2 with Ag doping. Assessing the optimal concentrations needed to produce a shift in the band gap energy, allowing the photocatalytic activity to be achieved under visible light conditions. These particles were then incorporated into a bonding resin and the effects on the photocatalytic properties were investigated.
Result:
Ag doping of TiO2 was achieved by combing various concentrations AgNO3 with Na2CO3 and ball milling for 48h with 10g of TiO2 in 100ml of deionised water. The slurry was then annealed and ground into fine powder. Ag-doped TiO2 was shown to produce effective photocatalytic activity under visible light conditions and the most effective Ag doping content was recorded. The powder was then incorporated into an epoxy resin and the surface was polished to uncover the embedded particles. The photocatalytic activity of the Ag-doped TiO2 was maintained after being incorporated into the resin. However, its effects were dramatically reduced as a result of the reduced particle surface area available. As only a low content of Ag was needed to achieve the desired effects, the resin produced was a very acceptable white colour, making it a suitable bonding agent for use with aesthetic orthodontic brackets.
Conclusion:
Demineralisation is still one of the major complications of orthodontic treatment, leading to unsightly WSL formation. This novel bonding resin could potentially provide long term antimicrobial protection and help prevent the occurrence of WSL formation, without relying on patient compliance.