Effect of eugenol-containing temporary cements on bond strength of composite to dentin

The effect of temporary materials on shear bond strength of composite to dentin was investigated. Sixty previously impacted (caries-free) human third molars were embedded and sectioned horizontally at the pulp chamber and at the half of the crown. The samples were covered with ZOE, Temp Bond (eugenol-containing), Fermit, (temporary resin material, used without cementing) and Provicol, (eugenol-free, calcium hydroxide-containing). All specimens were stored in saline for 10 days. After mechanical cleaning the dentin was pretreated with a dentin bonding agent (Syntac), and the composite columns were applied. Debonding was performed using a Zwick Universal Testing Machine (cross-head speed 1.5 mm/min). The mode of failure was noted using a light microscope, and the thickness of the dentin at the composite/dentin interface was measured. The median shear bond strength values for the treated and control samples were: ZOE 7.46 MPa, Temp Bond 10.22 MPa, Fermit 6.49 MPa, Provicol 8.43 MPa, and control 10.06 MPa. No two groups were significantly different at the 0.05 level (one-way ANOVA and Scheffé test). In all groups the predominant mode of failure was adhesive and there was a slight tendency towards lower shear bond strength values at lower values for the thickness of the dentin. Under the conditions described the use of eugenol-containing temporary cements had no adverse effect on shear bond strength of a dual-curing composite luting cement to dentin.