A Study on Imbibition and Syneresis in Four Commercially Available Irreversible Hydrocolloid (Alginate) Impression Materials

Purpose: To evaluate imbibition and syneresis in four commercially available irreversible hydrocolloid (alginate) impression materials at different time intervals (10, 20 and 30 minutes). Materials and methods: Eighty samples of four commercially available irreversible hydrocolloid (alginate) impression materials Algitex (DPI, Mumbai), Plastalgin (Septodont, Cedex, France), Zelgan 2002 (Dentsply), Finndent (Pyrex Polykem) were made. Twenty samples each of four irreversible hydrocolloid (alginate) impression materials were grouped into four groups (I, II, III and IV). Measured quantity of alginate powder and liquid was used to make samples. The samples were evaluated for imbibition and syneresis at different time intervals (i.e.10, 20, and 30 minutes) by weighing on electronic analytic balance. The data were analyzed using the one-way ANOVA, post hoc test and t-test. Results: The statistical data revealed that imbibition within four groups of irreversible hydrocolloid (alginate) impression materials were not significant. Regarding syneresis there was insignificant difference between the four groups but within the group itself they showed significant difference between them depending upon the time interval. It was observed that Group I showed significant difference in syneresis at time interval of 10 to 20 minutes. Group II showed significant difference in syneresis at time interval of 10 to 30 minutes. Conclusion: This study demonstrated that four groups of irreversible hydrocolloid (alginate) impression materials showed different rates of imbibition and syneresis at time interval of 10, 20 and 30 minutes depending upon molecular weight, calcium concentration and environmental conditions.