Mechanical Testing Performance of Reinforced Encapsulated Glass Ionomer Cements

Objectives: To evaluate the effect of resin coating on compressive strength of encapsulated glass ionomer cements.
Methods: A resin coating (EQUIA Coat,GC Europe,Leuven,Belgium) and a varnish (GC Varnish,GC Europe) were used for covering upper surfaces of samples. Three control groups [composite-resin, CR (Gradia Direct Posterior,GC Europe), non-coated EQUIA Fil, EF (EQUIA Fil,GC Europe), non-coated Riva Self Cure, RS (Riva Self Cure, SDI,Bayswater,VIC,Australia)], two resin-coated groups [resin-coated EQUIA Fil (CEF), resin-coated Riva Self Cure (CRS)] and two varnished groups [varnished EQUIA Fil (VEF), varnished Riva Self Cure (VRS)] used. Seven groups (n=10) were tested in three different time cycles (24hours, 7days, 30days). 4mm diameter and 6mm heigth of samples were prepared at 23⁰C in cylindrical shaped metal moulds according to instructions of manufacturer and stored in artificial saliva (SAGF Medium) at 37⁰C. A colorant pigment (0.01‰ Rhodamine B isothiocyanate,Merck,Darmstadt,Germany) added into resin coating and varnish for easy observation. A halogen light (Elipar Triligth,3M ESPE,ESPE Platz,Seefeld,Bavaria) used for polimerization of resin coating for 20 seconds. Ultrasonic cleanning (Elmasonic S,Elma Ultrasonic,Singen,Germany) was applied for 10 minutes before testing. The dimensional evaluation of samples were applied with a digital calliper (Super Solar Calliper, Mitutoyo, Michigan, USA) and the datas were computerized. Compressive strength tests were performed with on a universal test device (Zwick/Roell GmbH&Co. KG, Ulm, Germany) at a crosshead speed of 1 mm/min. One-way Anova, Tukey HDS test and T-test were used for statistical analysis at .05 significant degree.
Results: CR groups were evaluated highest values for each test periods (p<0.05). Non-coated glass ionomer cement groups were showed significantly higher results than coated and varnished groups and were reached highest values at the end of 30 days (p<0.05). Resin-coated groups were quantified similar compressive strength values for all test periods.
Conclusions: It was determined that resin coating application caused no increase on compressive strength of encapsulated glass ionomer cements.