effect of storage period on dimensional stability of alginplus and hydrogum 5

objectives: this study aimed to evaluate the effect of storage period on dimensional stability of alginplus and hydrogum 5. materials and methods: in this in vitro experimental study, 60 impressions were taken of an upper jaw typodont, including 10 impressions for each storage period to be tested (12 minutes, 24 and 120 hours) for each type of alginate. then, the impressions were stored in an incubator with stable temperature and humidity, and poured using a type iii dental stone. subsequently, the mesiodistal dimension, occlusogingival height, and interarch distance were measured using a digital caliper with an accuracy of 0.01mm. the data were analyzed using anova and t-test (p<0.05). results: alginplus and hydrogum 5 impressions were not significantly different from the master model after 12 minutes and 24 hours in terms of dimensions (p>0.05). after 120 hours, all dimensions measured on casts were significantly different from those measured on the master model, except for the mesiodistal dimension of the hydrogum 5 impressions. conclusions: at a consistent temperature and humidity, the alginplus and hydrogum 5 impressions were dimensionally stable for at least 24 hours. keywords: dimensional measurement accuracy; dental impression materials; alginic acid