Objective To compare the static frictional forces between stainless steel wire and bracket ligated with elastomeric ligatures fabricated from 4 formulations of epoxidized natural rubber and 3 different cross section configurations. Materials and methods The 0.016 x 0.022 inch stainless steel wire was used with the 0.018 inch slot first premolar standard edgewise stainless steel bracket and ligated with elastomeric ligatures fabricated from 4 formulations of epoxidized natural rubber which were rubber without silica, with 30phr silica, with 45phr silica, and with 55phr silica and each formulation has 3 different cross section configurations which were round, eclipse and rectangular.The static frictional force was measured by using the Shimadzu Universal Testing Machine. One-Way analysis of variance and multiple comparisons with Tamhane’s T2 were used to analyze the different of the static frictional force between groups at statistically significant level of 0.05. Results Elastomeric ligature without silica groups showed the lowest static frictional force followed by the 30phr silica, 45phr silica, and 55phr silica groups respectively.For the cross section configuration, the round groups showed the lowest static frictional force followed by the eclipse and rectangular groups respectively. There were statistically significant differences of static frictional force among all groups at level 0.05 except for the round and eclipse cross section groups.
