B Background: Glass ionomer cement (GJC) is one f dental materials for restorating class Vcavities caused by tooth brush abrasion. Objectives: To find out the influence of type and duration of brushing to the suface roughness of two glass ionomer cements. Method: The GIC can be mixed using hand and machine. In this research, type II GIC (Fuji IX, GC, Japan) with two kinds of manipulations, conventional and mechanical were used. Three different types of tooth brushes, Formula T&T (A), Pepsodent Double Care Sensitive (B) and Oral B All Round Micro-Thin Clean (C) were used to brush 2 groups samples for an hour and two hour respectively. Then the surface roughness of the samples were tested. Result: ANOVA showed a significant difference in surface roughnessof GIC conventional and mechanical (p