The aim of the study was to determine the effect of preprocedural mouthrinses used against COVID-19 on enamel/dentin shear bond strength (SBS) of a universal adhesive with different application strategies. Three hundred sound human mandibular anterior teeth were used for the study. The teeth were distributed according to the tooth substrates; enamel and dentin. After obtaining flat enamel/dentin surfaces, each substrate group was divided into a control and four experimental groups (n = 30): Group I (Control) – distilled water; Group II – 1.5% hydrogen peroxide (H2O2) (30 s); Group III – 1.5% H2O2 (60 s); Group IV – 0.2% povidone-iodine (PVP-I) (30 s); Group V – 0.2% PVP-I (60 s). Each group was then assigned into two subgroups according the application strategy of the universal adhesive, Prime & Bond Universal (n = 15); a-etch and rinse (ER) and b-self-etch (SE). The resin composite bonded assemblies were subjected to SBS testing after 24 h. The failure modes and SEM investigations were evaluated. Statistical analysis involved four-way ANOVA with pair-wise comparisons using Bonferroni correction test (p < 0.05). On enamel, the highest SBS in ER application strategy were determined for the control group, followed by PVP-I and H2O2 group, respectively (p < 0.05). For self-etch strategy, no significant difference was detected among the groups (p > 0.05). The ER application mode showed higher SBS on enamel (p < 0.05) except for group H2O2 for 30 s. There was no difference between the dentin SBS of control and mouthrinse groups regardless of application mode (p > 0.05). In comparison between the rinsing times, 60 s rinsing significantly improved the enamel SBS when ER mode was used(p < 0.05). Neither rinsing period, nor adhesive strategy affected the dentin SBS (p > 0.05). The preprocedural usage of antiseptic mouthrinses and their rinsing times affect the bonding performance of the universal adhesive only on enamel surfaces in ER mode.