Suppose you have yellowish teeth. If you were to do a video or photoshoot and wanted to have a white smile, how would you go about whitening your teeth temporarily for the duration of a few hours to a few days?
The easiest way to whiten or lighten teeth for a video or photo shoot is to have the visual SFX people whiten them for you in post-production with After Effects, Mocca, or other software.
After that, the make-up department technicians know what will pass for on-camera use.
Your own dentist can recommend a procedure to use.
A pharmacy or department store with a cosmetics department typically have several "solutions" made to whiten and brighten teeth and dentures so that they match under different lighting. This is called a metameric match which is hard to achieve non-professionally.
Some think that a "California Smile" looks fake and artificial on older people.
Good luck. Have a good shoot! Break a leg!
@Stan provided a to-the-point answer. I want to add something extra.
Most teeth-whitening techniques use some chemicals, which have a VERY NASTY side effect: they destroy the structure of the teeth. Sometimes, only a few whitenings are enough to have the teeth completely destroyed, i.e. the material actually missing.
Example: H2O2 (hydrogen peroxide) will whiten your teeth magically. Except that after a few whitenings, the teeth will just break and "disappear".
A former colleague told us the story of his village. People heard the trick with the hydrogen peroxide - and used it massively. In less than one year, (almost) nobody in the village had teeth any more.
So the healthiest way to do that is to have the photo / video processed with some filter, either from the beginning (using the camera capabilities), or using some computer software on the photo.