**4. Water fuoridation in Nigeria**

The mottling and staining of teeth (dental caries) previously believed to be an identity of certain ethnic groups or communities in Nigeria has been described to be associated with fluorosis [18]. Hence dental caries has extended beyond tribal or communal barriers as foreigners that came from far away Asia also showed evidence of this disease condition [15]. From records, the prevalence of dental caries was greatly reduced in areas where dental caries was endemic following fluoridation of public water supplies [3]. However in Nigeria, dental caries is endemic and epidemic mainly in the North Eastern half of Nigeria both in the crystalline basement and sedimentary areas. Also, fluoride values (0.2–8 mg/L) above the 1.5 mg/L WHO recommended level have been recorded in groundwater in Nigeria (**Figure 1**) [15, 20].

#### **Figure 1.**

*Areas with drinking water containing fluoride levels higher than 0.8 ppm in the six geopolitical zones of Nigeria [19].*
