Influence of the powder/liquid ratio on the properties of zinc oxide–eugenol-based root canal sealers

Objective: The purpose of this study was to investigate the effects of modifications of the powder/liquid ratio by endodontists on the physical properties recommended by ISO standards as well as on other clinically relevant properties of zinc oxide–eugenol-based root canal sealers. Methods: The powder/liquid ratio of two zinc oxide–eugenol-based root canal sealers (Cortisomol and Pulp Canal Sealer EWT) was recorded by 10 endodontists. The materials, prepared according to the different consistencies, were tested according to ISO standards to evaluate their physical properties. Their sealing efficiency and the release of eugenol were also evaluated on 20 single rooted teeth. Results: Some results varied according to the material. Nevertheless, for both cements, an increased powder/liquid ratio led to a decreased flow, an increased radiopacity and a decreased amount of eugenol released. The variations in the powder/liquid ratio did not influence the dimensional changes and the apical leakage of both cements. Significance: Variations in the powder/liquid ratio of zinc oxide–eugenol-based root canal sealers have a limited influence on the properties of the sealers. The endodontists can prepare the zinc oxide–eugenol-based root canal sealers at their chosen consistency according to the filling technique they use.