Objectives: This in vitro study aimed to investigate and compare the effect of su rface pretreatment with Diamine Silver Fluoride (DSF) and silver fluoride (SF) on the microshear bond strength (μSBS) of universal adhesives to dentin and micro morphological analysis of tooth restoration interface. Methods:Sixty freshly extracted sound human molars were selected and randomly divided into three groups(n=20)according to the surface pretreatment applied as following: control group (no pretreatment applied),DSF group and SF group. Each group was further subdivided into imme diate and aged subgroups(n=10). After mid-dentin exposure and pretreatment, universal adhesive and resin composite were applied and light-cured separately. μSBS was tesed using a universal testing machine.Micromorphological analysis of the dentin-resin interface was performed using Scanning Electron Microscope (SEM) for selected samples from each group.Two-way Anova was conducted and followed by Tukey's post-hoc multiple comparison tests were conducted. Results:Regarding μSBS,twoway Anova test revealed statistically significant differences among the study subg roups(p<0.05).Tukey's post-hoc multiple comparison test revealed no significant dif ferences between the three immediate subgroups(p>0.05).while within the aged s ubgroups,the control subgroup showed significantly higher μ SBS compared to D SF and SF subgroups(p<0.05).There were no significant differences between the i mmediate and aged subgroups(p>0.05)except for the control group that demonstr ated statistically significant increase in the μ SBS of the aged subgroup compar ed to the immediate one(p<0.05). Conclusion: Surface pretreatment with either DSF or SF had adverse effect on the bonding a bility or durability of the universal adhesive to dentin