STATEMENT OF THE PROBLEM: Acidic foods and drinks can erode composite resins. @entity16971 -based composite is a new low shrinkage composite with higher hydrophobicity which might resist the erosive effect of beverages. PURPOSE: The aim of this study was to determine the effects of 100% orange juice and non-alcoholic carbonated beer on microhardness of a @entity16971 -based composite in comparison with two @entity11379 -based composite resins. MATERIALS AND METHOD: Ninety disc-shaped composite specimens were fabricated of Filtek @entity12328 , Filtek Z350 XT Enamel and Filtek Z250 (3M-ESPE) (n=30) and randomly divided into 3 subgroups of 10.Group 1 was immersed in distilled water, group 2 in 100% orange juice, and group 3 in non-alcoholic beer for 3 h/day. Primary, secondary and final Vickers microhardness tests were performed at the beginning of the study and 7 and 28 days later. Surface of 2 specimens in each group was evaluated under scanning electron microscope on day 28. Data were analyzed using repeated measures of ANOVA model (a=0.05). RESULTS: The primary and secondary microhardness of @entity12328 was significantly lower than that of Z350, and Z250 (p< 0.001). Microhardness of Z350 was also lower than that of Z250 (p= 0.002). On day 28, microhardness of @entity12328 was lower than Z250 and Z350 (p< 0.001); however, microhardness values of Z250 and Z350 were not significantly different (p= 0.054). Microhardness of specimens subjected to non-alcoholic beer was significantly lower than that of controls (p= 0.003). Meanwhile, the microhardness value of resins in orange juice was somewhere between the two mentioned values with no significant difference with any of them (p> 0.05). CONCLUSION: Although 28 days of immersion in 100% orange juice and non-alcoholic beer decreased the microhardness of all specimens, @entity12328 experienced the greatest reduction of microhardness and non-alcoholic beer had the highest effect on reducing microhardness.

Comparison of the Effects of Two Different Drinks on Microhardness of a XXXX -based Composite Resin.

@entity16971 :: ('MESH:D062047', 'Chemical') :: ['Silorane', 'silorane'] @entity11379 :: ('CHEBI:25218', 'Chemical') :: ['methacrylate'] @entity12328 :: ('57650', 'Gene') :: ['P90']
@entity16971 :: (MESH:D062047,Chemical) :: ['Silorane']
