Meta-analyses suggest water fluoridation reduces cavities by approximately 0.25 cavities per person, which may not be statistically significant.

“there was a meta analysis that came out that further supported the ntp report by Jamma Pediatrics okay and this is very controversial for these editors to be putting out by the way so I commend them um and also a Cochran report came out Cochran collaborative which has said this again was very recent looking at all the data from water fluoridation water fluoridation isn't reducing Decay like we thought it was it's only reducing Decay by about one quar a cavity per person one quarter of a cavity per person so that's not statistically significant”