Effect of Polyether Retarder on the Flowability of Impregum Soft

Objectives: To determine the effect of different lengths of Polyether retarder on the flowability of Polyether impression material.

Material and methods: Medium-bodied consistency ImpregumTM Soft (3M ESPE, Germany) was investigated with and without retarder. The length of the strands of the retarder varied from 0, 0.5, 1.0, 1.5 and 2 times the lengths of the strands of the catalyst/base paste. All tests are carried out at 30s intervals until manufacturer's recommended working time after end of mixing (30s, 60s, 90s, and 120s) at room temperature (32±2°C). One hundred impression are made (n=5) on shark fin model. Fin heights were analysed by One-Way ANOVA. Where significant differences in the groups were found, a comparison of individual means was performed by Tukey HSD post hoc tests.

Results: One-Way ANOVA revealed significant differences among the lengths of the retarder (P<0.01). There is no significant difference between the longer length of retarder (1.5 and 2 times groups) at the short working time (30s). At the 60s working time, there is no significant difference between 0.5 and 1.0 times groups. The longest length of retarder showed significantly greatest fin height at the 90s working time (P<0.01).

Conclusion: The longer the retarder the lengthener the working time. Therefore, Polyether retarder can improve the flowability of Impregum Soft. In clinical application, it is suggested that Polyether retarder can be used for lengthening the working time and achieving better flow characteristics of Polyether.