Abstract 

Dental caries is a widespread infectious disease influenced by bacterial activity, dietary factors, and host 

susceptibility. Community water fluoridation has been a key public health measure for caries prevention, 

particularly in children. The optimal fluoride concentration in drinking water (0.7 mg/L) balances caries 

reduction with minimal fluorosis risk. This study assessed fluoride levels in drinking water and their 

correlation with dental caries in primary school children in Gharyan, Libya. A cross-sectional study was 

conducted on 350 children (aged 7–10 years) from urban and rural schools in Gharyan. Water samples from 

five stores and one groundwater source were analyzed for fluoride concentration using an ion-selective 

electrode. Dental caries was assessed using the dmft/DMFT index. Fluoride levels in water stores were 

negligible (0.0–0.1 mg/L), while unfiltered groundwater exhibited high concentrations (6.0–7.0 mg/L), 

exceeding WHO guidelines (1.5 mg/L). The low fluoride availability in most drinking sources suggests 

limited caries-preventive effects from water fluoridation in this region. The study highlights insufficient 

fluoride exposure in Gharyan’s public water supply, potentially contributing to higher caries prevalence. 

Further research is needed to evaluate alternative fluoride delivery methods and assess groundwater safety 

to optimize oral health outcomes.

Keywords. Fluoride Concentration, Drinking Water, Dental Caries, Primary School.