Objective To evaluate the effect of an arginine-containing antihypersensitivity polishing paste on Streptococ-cus mutans (S. mutans) adhesion to treated dentin.Methods Dentin discs were treated with acid to expose dentin tubules, and then polished with either pumice or a polishing paste containing arginine. The surface roughness of the treated dentin was measured. The effects of dentin treatment on S. mutans adhesion and glucosyltransferase (GTFs) gene expression were also evaluated.Results The surface roughness decreased after polishing with both pumice and arginine-containing polishing paste. Moreover, the polishing paste affected gtfB and gtfC expressions.Conclusion The arginine-containing polishing paste affects S. mutans adhesion, as well as gtfB and gtfC expressions. The polishing paste may be used to prevent caries in exposed dentin areas.