Background and objective: Aesthetics is mostly a subjective perception that varies from individual to individual. The main objective of this study was to evaluate and compare the effects of LASER and light emitting diode bleaching techniques on the micro-leakage of composite resin restorations that were bonded with fifth and seventh adhesive bonding generations. Methods: Standardized cavity preparations were performed on 60 maxillary premolars and samples were divided into three groups according to the two adhesive systems (fifth and seventh) generation. After cavities were restored with two different adhesive systems and restored with composite resin, they were submitted to thermo-cycling procedures. Teeth were divided into six sub-groups according to the bleaching systems (control, in-office bleaching by light emitting diode (LED), LASER-activated in-office bleaching). After the bleaching procedure, teeth were evaluated for marginal leakage. All data were analyzed using the Mann-Whitney U and Kruskal-Wallis tests (p < 0.05) Results: The results of the present study showed that the control group presented lower micro -leakage values compared with the groups treated with bleaching agents. When the scores of micro-leakage of the six subgroups were compared, the differences among the groups were found to be statistically significant (p < 0.001). there was no significant difference found between the adhesive systems after treatment with the same bleaching techniques. Conclusion: Under the conditions of this study, micro-leakage of composite resin restorations differs according to the bleaching techniques used with no significant difference was found between the adhesive systems, and restorations post bleaching procedure was necessitate replacing by the clinician due adverse effects on tooth restoration interface.