Which is the most appropriate claim to include in a sponsored ad running in May 2022?
- Leave teeth three shades whiter than other brands
- Leave teeth three shades whiter than other brands. Research completed by Dental Weekly Magazine, April 2022
- Leave teeth three shades whiter than other brands. Research completed by Dental Weekly Magazine, April 21, 2019
- Leave teeth three shades whiter than other brands according to experts