Blood contamination and dentin bonding—effect of anticoagulant in laboratory studies

Objective: To investigate the influence of heparinized blood vs. native blood on the marginal adaptation of dentin bonded composite resin restorations. Methods: Cylindrical dentin cavities were prepared in 40 extracted human incisors. After acid-etching four groups (n=10) were contaminated with either fresh capillary blood (FCB), heparinized venous blood (HPB), saline (SAL) or heparinized saline (HPS) and bonded and filled with Scotchbond 1/Z 100. After water storage for 21 days and thermocycling (2000×, 5–55°C), replicas were produced for evaluation of marginal adaptation by means of quantitative marginal analysis in the SEM. Statistical analysis was performed with the Kruskal-Wallis-test and the Bonferroni correction for multiple comparisons at p<0.05. Results: There were no differences between groups SAL, HPS and HPB. Contamination with fresh capillary blood resulted in significantly higher amounts of marginal openings compared to all other groups. Significance: Freshly drawn blood has to be used for blood contamination experiments in laboratory studies.