The presence of fluoride in communal water supplies have demonstrated appreciably lesser benefits, this is due to:

 # The presence of fluoride in communal water supplies have demonstrated appreciably lesser benefits, this is due to 

A. Adverse effect 

B. Halo effect 

C. Bacteriostatic effect 

D. None of the above 

The correct answer is B. Halo effect.

Several studies concerning the reduced prevalence of dental caries associated with the presence of fluoride in communal water supplies have demonstrated appreciably lesser benefits, typically ranging between 18% and 30%. This decrease in attributable benefit is due to the so-called halo effect associated with the preparation of numerous foods and beverages in fluoridated communities and their consumption in nonfluoridated communities.

Reference: Mc Donald 2nd South Asian Edition