A bit more info:
There is one newer paper (dental materials 24, 2008, 1036-1042) where they warn against extended use of blue light exposure. In their study they induced cell death in human gingival fibroblasts. The cells irradiated were in 96 well culture plates.
So these are "normal" cells. (Inasmuch as a cell in culture is normal)
(J. Dent. Research. 83, 2004, 105-) where they looked at normal and cancer cell CULTURE. Ref therein states (Mechanism presumably mitochondria mediated)
also in 2005
http://www3.interscience.wiley.com/journal/112426016/abstract?CRETRY=1&SRETRY=0 and more recent: DENTSPLY/Caulk - Basic Science Category April 2008
These are poster sessions and not peer rewieved journal articles
http://iadr.confex.com/iadr/2008Dallas/techprogram/session_18878.htmThe first on is the mouse work (10 mice only). Cultured A431 human epidermoid carcinoma cells were injected subcutaneously into the abdomens of female mice and then treated with blue light.
In the second one (0630) Normal human epidermal keratinocytes (NHEK) and oral squamous carcinoma cells (OSC2) were seeded onto coverslips in six well plates, and treated with blue light.
This is certainly interesting but needs a LOT more research, and even then the physical properties of light may make this a surface treatment at best in my opinion.
M
