Introduction: The aims of the study were to investigate the enamel and dentin marginal seal of a universal adhesive system applied with etch and rinse and selfetch strategy and to evaluate the enamel and dentin marginal microleakage in case of saliva contamination on different steps of the adhesive application by dye penetration assessment. Methodology: Thirty class V cavities were prepared on the buccal face (group I-etch and rinse application of universal adhesive system) and the lingual face (group II-self-etch application of universal adhesive system) of molars and bicuspids. In each group 3 subgroups were created according to the moment of the saliva contamination: subgroup 1-no contamination, subgroup 2-contamination before light curing the adhesive, subgroup 3-contamination after light curing the adhesive. The dye penetration at the adhesive interface was evaluated according to a 4-score scale. Results: In both groups increased enamel and dentin microleakage was recorded in subgroups 2 and 3 when comparing to subgroup 1. In group I saliva contamination before and after light curing the adhesive resin led to similar mean value of dentin microleakage. Increased values of microleakage were recorded in group II when comparing to group I in the subgroups where contamination with saliva was done before light curing the adhesive resin. Conclusions: Saliva contamination of the adhesive system after light curing increased enamel microleakage only when the adhesive system was applied with etch and rinse strategy. Increased dentin microleakage after contamination was recorded with both strategies of universal adhesive system application.