Retentive and compressive strengths of modified zinc oxide-eugenol cements

Objectives: This investigation sought to improve the handling and physical properties of a commonly used temporary zinc oxide-eugenol cement by changi ng the base/accelerator (B/A) ratio or combining it with a petroleum jelly or fluoride varnish. Methods: Twelve modifications of a temporary cement were evaluated in terms of retentive strength, compressive strength at 24 h, film thickness and by scanning electron microscopy. Results: Decreasing the B/A mixing ratio increased the retentive and compre ssive strengths, but reduced the film thickness of the cement. By increasin g the percentage of incorporated petroleum jelly or fluoride varnish in the cement, there was a progressive decrease in the retentive and compressive strengths and in film thickness. Conclusions: Modifications of a zinc oxide-eugenol temporary cement to chan ge the B/A ratio or to incorporate additives resulted in variations in phys ical properties. All modified forms of the cement had a film thickness less than 25 mu m and a compressive strength below 35 MPa. With a wide range of retentive strength, modified forms of zinc oxide-eugenol cement may be fou nd to have diverse clinical applications. (C) 1999 Elsevier Science Ltd. Al l rights reserved.