Dimensional Integrity and Mechanical Stability of a Novel Temporary Cement

Objectives: Goal of this study was to investigate the longer-term stability of an experimental temporary cement when compared to other cements.
Methods: Experimental temporary cement (EXPTC, 3M Oral Care), a zinc oxide non-eugenol temporary cement (TempBond^® NE, TBNE, Kerr), and a zinc oxide eugenol temporary cement (TempBond^®, TBO, Kerr) were studied. All materials were used per their instructions-for-use. Cylindrical samples with diameter of 4 mm and height of 7 mm were made for compressive strength per ISO 3107 guidance. Also, discs of 20 mm diameter and 1 mm thickness were molded for linear-expansion measurements. All samples were cured and conditioned in 37C/95% chamber prior to removing molds and storing in 37C de-ionized water for extended time. Compressive strength samples were broken in compressive mode using Instron machine, and linear-expansion strains were calculated by monitoring the disc diameter change by an optical microscope.
Results: Mean values for properties, including standard deviations are summarized in following table:
Conclusions: ANOVA analysis was performed at p < 0.05 per Tukey’s pairwise comparison test. EXPTC had significantly higher compressive strength than TBNE and TBO, while there was no statistical difference between days 1 and 7 values for any of the cements. Although at day 1 there was statistically no significant difference between EXPTC and TBNE in hygroscopic linear expansion, EXPTC exhibited significantly lower expansion after 1 week immersion in water. The longer-term strength and hygroscopic expansion profiles of EXPTC suggest its acceptable mechanical and dimensional stabilities to retain temporary crowns in clinical setting.