Water Sorption of Various Restorative Materials in Artificial Saliva

Objective: The purpose of this study was to determine the water sorption of a compomer (Compoglass F; Ivoclar Vivadent),  a microhybrid (Miris; Coltène), a hybrid (Filtek Z-250; 3MESPE), a microhybrid (Clearfil ST; Kuraray) and a packable composite (SureFil; Dentsply) at 1, 7, 14 days. Methods: Test specimens 2 mm in thickness and 6 mm in diameter were prepared in teflon moulds using a standard dental curing light (Heliolux DLX-Vivadent) (n=20). All specimens were kept dry in a dessicating chamber at 37^oC for 24 hours and were weighed with a sensitive balance (Scaltec Instruments 1/10000) to determine the constant weight. Then the specimens were immersed in artificial saliva and weight changes were measured at intervals of 1, 7, 14 days. The statistical analysis were evaluated between 1^st and 7^th days, 1^st and 14^th days and 7^th and 14^th days by using Independent t-test and  Paired t-test. Results: Mean water sorption values of restorative materials in days 1, 7 and 14 days are given below (in gr).

All restorative materials displayed a statistically significant water sorption differences between each other and also 1^st, 7^th and 14^th day, except between Compoglass F and Clearfil ST between 1^st and 14^th day. Conclusion: In spite of the differences in resin formulations, all materials still showed water sorption at the end of the 14^th day.