Why don't teeth glow?
Just to add a little more on the interface between optics and dentistry:

Whilst teeth do not phosphoresce, they do in fact autofluoresce.

The differential auto fluorescence of healthy tooth and carious tooth has been used for the early diagnosis of caries. (Gugnani N, Pandit IK, Srivastava N, Gupta M, Gugnani S. Light induced fluorescence evaluation: A novel concept for caries diagnosis and excavation. J Conserv Dent 2011;14:418-22 and http://www.opticsinfobase.org/boe/abstract.cfm?uri=boe-2-1-149)

To see teeth glow, or rather, fluoresce, they should be illuminated with short wavelength light, like blue light (wavelength 450 nm) and the teeth will glow green, which will be visible if the the blue light is filtered out.

Also see http://www.inspektor.nl/dental/qlfmain.htm#QLF%99%20Basic%20Principle