Time dependant action of titanium dioxide photocatalyst incorporated in soft liners
Objective: To determine the duration of action of titanium dioxide photocatalyst incorporated in soft liners
Methodology: Specimens were prepared by mixing 1.5g Titanium dioxide photocatalyst (TiO2) powder with 5 ml of tissue conditioner liquid. This was added to 8g of tissue conditioner powder to get a concentration of 15% (w/w) of photocatalyst /tissue conditioner powder. 2 sheets of modelling wax were adapted together and a square recess of dimension 20x20x4mm was cut. The soft liner/photocatalyst mixture was poured into these squares. This was then sandwiched between 2 glass slabs and square shaped specimens were obtained (group P). Control group specimens (group T) were prepared by mixing Tissue conditioner powder and liquid according to manufacturers instructions. Both the specimen groups were placed in a UV chamber for a period of 12 hours. After irradiation specimens were immersed in 10ml of 0.01mM methylene blue in ethanol for 3 hours. For the determination of the photocatalytic activity, the absorbance of methylene blue was calculated at 650nm using a spectrophotometer. The absorbance of methylene blue was calculated at 1,15 and 30 days for both the groups.
Result: The absorbance of Methylene blue in the photocatalyst containing specimens was 0.8 AU at day 1, 0.72 AU at day 15 and 0.64 AU at day 30 and was significantly lower than that of the control group(0.9AU).
Conclusion: The photocatalytic ability of titanium dioxide was maintained for a period of 30 days when incorporated in soft liners.