The effect of desiccation on water sorption, solubility and hygroscopic volumetric expansion of dentine replacement materials

Publication date: Available online 24 May 2018
Source:Dental Materials
Author(s): Ruba Mustafa, Ruwaida Z. Alshali, Nick Silikas
ObjectiveTo evaluate water sorption, solubility and hygroscopic expansion and the effect of desiccation for a calcium silicate-based material, a conventional glass ionomer, and a resin-modified glass ionomer.MethodsWater sorption, solubility and hygroscopic expansion of Biodentine™ (BD), GC Fuji IX GP^® FAST (FJ), and Ionolux (IO) were tested under two pre-storage conditions: with desiccation and without desiccation. Disc-shaped samples (n=5) were immersed in water and weighed at different time intervals (1h, 24h, 3d, 7d and 30d) and hygroscopic expansion was recorded at 7d and 30d. Data were analysed using Factorial repeated measures ANOVA, one-way/two-way ANOVA, Independent samples t-test and Tukey's post hoc test (α=0.05).ResultsWith desiccation, sorption of IO and FJ was 124.33μg/mm³ and 79.97μg/mm³ respectively. Solubility was −12.36μg/mm³ for IO and −20.19μg/mm³ for FJ. Hygroscopic expansion was 3.01% for IO and −2.35% for FJ.Without desiccation, sorption was in the order: IO˃BD˃FJ (130.35μg/mm³, 122.07μg/mm³, and 107.21μg/mm³ respectively), while solubility order was: BD˃FJ˃IO (154.83μg/mm³, 88.82μg/mm³, and 25.67μg/mm³ respectively). IO and FJ showed significant difference in sorption and solubility between the two pre-storage treatment groups (p˂0.005). Hygroscopic expansion was in the order: IO˃BD˃FJ.SignificanceBD had the highest solubility while IO had the least. The relatively stable polymeric resin in IO may contribute to its low solubility but high hygroscopic expansion. Desiccation had significant effect on sorption, solubility and volumetric expansion of water-based materials.



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