Some of this effect is the medium of Technicolor film messing with your relationship to color. Technicolor was not a very true-to-life color representation, everything is highly saturated, so reds look redder, blues look bluer, and of course whites look whiter. It's like a detergent ad! :) The Technicolor company had a color-corrector on site for filming to help work within the limitations of this filming system, like Dorothy's costume in the Wizard of Oz famously had a pale pink shirt, because the white would look too crazy bright on film. However I guess you've found a nice side-effect of the over-saturation - it made normal teeth look super great!