Objective: To assess the effect of 5% sodium fluoride (NaF) varnish application in prevention of caries in mixed dentition rural Jamshoro school children over the course of 6 months.

Methods: children with lower stage caries aged 7 to 10 years were included. Students were equally divided in two groups. In Group-A students, 5% fluoride varnish was applied. While in children of control group necessary instructions were given to the student about dietary control. After 3 months, varnish applied teeth on both group’s children were examined again and the rate of caries were documented by using DMFT. After 3 months fluoride varnish was applied to both groups using same method and same directives. Dental caries was examined using the DMFT score after six months of application of fluoride varnish in both groups. All the data was recorded in the proforma.

Results: In this study total 108 children were studied, there was no significant difference according to age  and brush frequency among both groups p-value 0.146 and 0.088 respectively. Most of the children were using brush among both groups. A starting of the trail mean of DMFT was 1.22+0.24 in group A and 1.39+0.56 in group B. After 3 months it was almost equal among both groups as, while on six months assessment DMFT was raised in control group in contrast to test group p-value 0.012

Conclusion: It was concluded there was significant preventive effect/impact of fluoride varnish on dental caries. DMFT was raised in control group during 6 months rather than test group.