The aim of this work was to characterize quantitatively the contribution of different failure modes during shear bond strength (SBS) measurements and to correlate both those sets of results. Four experimental dental adhesive systems were used to join dental composite with cobalt-based alloy plate. The samples were subjected to SBS measurements according to International Organization for Standardization (ISO) procedure and resulting fractures were examined by optical microscopy, including computer-aided processing of the images, to yield quantitative contributions of adhesive and cohesive failures. Identification of particular failure modes as well as quantitative determination of respective contributions appeared to be possible. The data were processed by statistical methods including Shapiro-Wilk and Mann-Whitney U tests. The results of fractographic analysis were found to correlate with SBS values. Contribution of adhesive failures appeared to determine the strength of adhesive bonds. A new dental adhesive system based on PM2EDM monomer exhibited a very good performance in respect to the metal alloy.