Evaluation of Tear Strength of Two Types of Iralgin and its Comparison with Similar Alginate Impression Material

Objectives: Among the various impression materials, for alginate tear strength is probably more important than the compressive strength. The tear strength is important when an impression involves a mechanical undercut and/or lacks bulk strength to resist tearing. This study evaluated tear strength of Iralgin and compared it with tear strength of Alginoplast. Methods: In this invitro experimental study A mold was made with 100mm×20mm×1mm dimensions and a longitudinal prominence in 0.3 mm depth. Twenty–seven specimens (9 Super Iralgin, 9 Pocket Iralgin, and 9 Alginoplast) were selected non–randomizedly. Each specimen prepared corresponding to manufacturer and injected into the mold. an‎d the mold was placed under press. After removing the mold from press, every specimen formed as a trouser-shaped specimen. The specimen was pulled in tensile machine with 50 mm/min speed. The data of specimens in different groups were statistically analyzed using one-way ANOVA, Kolmogorov-Smirnov, and Levene's tests. Results: first specimen ( in tear strength Mean ofS second uper Iralgin), s ( pecimenP were 640 (Alginoplast) third specimen and ocket Iralgin),±38 grf/cm², 500 ±20grf/cm², and 1100±27 grf/cm² respectively. According to ANOVA test, the mean of tear strength was not equal in three specimens (p<0.01). According to LSD Multiple Comparison, the first and second specimens were same in tear strength, whereas the third specimen was different from the two former (p<0.05 and p<0.01). Conclusion: Super Iralgin and pocket Iralgin were the same in tear strength. Alginoplast was significantly higher than super and pocket Iralgin in tear strength.