Abstract： Objective To evaluate the effect of an 8％ arginine-CaCO3 containing desensitizing polishing paste on bonding strength of two self-etching adhesives to dentin.Methods Thirty-six intact human premolars extracted for orthodontic reasons were collected within 1 month after extraction and randomly assigned into three groups using a table of random numbers (n =12): specimens without any treatment served as control.In the polishing powder group specimens were polished with a slurry of pumice,and in the desensitizing polishing paste group dentin surfaces of the sample teeth were treated with 8％ arginine-CaCO3 containing desensitizing polishing paste.Then each group was divided into two sub-groups using a table of random numbers in order to evaluate the bonding strength of two self-etching adhesive agents (G-Bond,GC; Fl-Bond Ⅱ,Shofu).Microtensile bond strength test was conducted immediately and after 5000 thermocycling (n =15).Scanning electron microscope (SEM) was used to evaluate the occluding effect of the desensitizing polishing paste.Results In the prethermocycling stage,there were no significant differences in Fl-Bond Ⅱ bonding strength among the three groups [control: (30.34 ± 5.42) MPa,polishing powder group: (29.72 ± 5.16) MPa,desensitizing polishing paste group: (31.53 ± 4.86) MPa] (P ＞ 0.05).However there were significant differences among the three groups in G-Bond bonding strength [control: (38.19 ±4.42) MPa,polishing powder group: (36.47 ± 4.72) MPa,desensitizing polishing paste group: (46.88 ±7.83) MPa] (P ＜0.05).After thermocycling precess,there were no significant differences in bonding strenght among the three groups in both G-Bond groups and Fl-Bond Ⅱ groups.SEM observation showed that the desensitizing polishing paste could occlude open dentinal tubules effectively,and the application of self-etching adhesives could re-open the dentinal tubular orifices.An even layer can be seen on the dentin surface treated with self-etching adhesive containing functional monomers.Conclusions The 8％ arginine-CaCO3 containing desensitizing polishing paste could effectively occlude dentinal tubules,thus may have potential benefits in preventing post-operative sensitivity.Additionally,it had no adverse effect on bonding strength of self-etching adhesives to dentin.