Nam SH, et al. - In the study presented here, the structural-morphological changes were evaluated in enamel surface roughness and Streptococcus mutans adhesion after tooth bleaching using plasma in combination with a low concentration of 15% carbamide peroxide (CP). Data reported that the application of plasma did not result in any structural-morphological and topographic changes in the enamel. Findings revealed that the combinational bleaching method using plasma and a low concentration of 15% CP was less destructive, especially with respect to tooth surface protection.