How effective and cost-effective is water fluoridation for adults and adolescents? The LOTUS 10-year retrospective cohort study.

Receipt of optimal water fluoridation 2010-2020 resulted in very small positive health effects which may not be meaningful for individuals. Existing fluoridation programmes in England produced a positive return on investment between 2010 and 2020 due to slightly lower NHS dental care utilization. This return should be evaluated against the projected costs and lifespan of any proposed capital investment in water fluoridation, including new programmes.