Does eugenol affect the microtensile bond strength of self-adhering composite? - An in vitro study

The objective of the study is to evaluate the effect of eugenol-based temporary on microtensile bond strength of self-adhering composite at 1 day and 7-day time intervals.

Occlusal enamel of 24 human molars was removed. Zinc oxide eugenol (ZnOE) and noneugenol temporary cement (ZnONE) were placed on the dentin surfaces and left for different times (1 day, 7 days). After removal of temporary cement, teeth were randomly divided into eight subgroups: subgroup GE1S (n = 3): ZnOE cement + Self-adhering composite (SAC), subgroup GE1N (n = 3): ZnOE cement + adhesive system (one coat 7 universal) + nanohybrid composite, subgroup GE7S (n = 3): ZnOE cement + SAC, subgroup GE7N (n = 3): ZnOE cement + adhesive system + nanohybrid composite, subgroup GNE1S (n = 3): ZnONE cement + SAC, subgroup GNE1N (n = 3): ZnONE cement + adhesive system + nanohybrid composite, subgroup GNE7S (n = 3): ZnONE cement + SAC, subgroup GNE7N (n = 3): ZnONE cement + adhesive system + nanohybrid composite. Four sticks per tooth were obtained, resulting in 12 sticks per group with a cross-sectional area of 0.5 mm ². The μTBS test was performed with a crosshead speed of 0.5 mm/min.

Kruskal-Wallis and Mann-Whitney U-test were used for analysis.

Highest and lowest mean value of microtensile bond strength was observed in GNE7N (12.75MPa) and GE1S (1.42MPa), respectively.

The presence of eugenol at early stage, i.e. 1 day, has a negative influence on microtensile bond strength of SAC. At 7 days, the negative effect of eugenol on microtensile bond strength gets nullified. Thus, a waiting period of 1 week is sufficient to overcome negative influence of eugenol-based temporaries on polymerization of SAC.