The Investigation of HEMA realesing and water absorption of resin modified glass ionomer cements

-81- SUMMARY Resin modified glass ionomer cements are developed with the addition of resin ( hydrxyethyl metacrylate ) to the conventional glass inomer cements. The addition of resin increases the adhesion properties, but from the biologyical aspect it has some disadvantages. The aim of this study is to evaluate the amount of hydrxyethyl metacrylate (HEMA) level released from different modified glass ionomer cements. In this in vitro study, Advance (Caulk/Denstpley Inc.,U.S.A), Vitramer (3M Dental Products, U.S.A.) ve Protec-Cem (R&D Vivadent, Liechtenstein) resin modified the amount of HEMA level released from different resin modified glass ionomer cements and water absorbtion level. To evaluate the HEMA released the specimen are prepared considering the ADA 9 standart, 10 mm diamater, 1 mm height, foreach of cements 10 specimen were prepared, the total number of the specimen were 30. The specimen were immersed glass containers containing 20 ml deionize water after 10 minutes, 1 hour, 24 hour and 7 days storage from each group 1ml solution is taken from the cotainer and transferred the glass tubes vory a micropipet. These solution are injected to high performans liquid cromatography ( HPLC ) machine and the results are calculated in term of ppm. To evaluate the water absorbtion of resin modified glass ionomer cements according to the ISO 4049 standars the specimens were prepared at 15 mm-82- diamater, 1mm depth, for each cement group 10 specimen were prepared. the samples are dried and weight of a balanced analyzer and obtained the Mi value. After that the specimens are left in deionized water for 7 days and than weighted again and obtained the M2 value. Inorder to obtain M3 value, the specimen are washed, dried and weight again. The result of the water absorbtion were obtained in ugr/mm3. Among the groups HEMA release was maximum at vitramer and minimum at Protec-Cem cements. Water absorbtion results were parallel to the results of the HEMA release results, maximum water absorbtion was at Vitramer and minimum water absorbtion was found in Protec-Cem.