Objectives: This study aimed to evaluate and compare the efficacy of composite releasing Ca and PO4 ions versus conventional glass Ionomer, resin-modified glass Ionomer and hybrid composite regarding remineralization capacity and Microleakage. Methods: thirty-four caries-free premolars were used, and class v cavities were prepared on each tooth. These teeth were divided into four groups and restored with the following materials : (Resin-modified glass Ionomer RMGI, Glass Ionomer GI, Hybrid composite HC, Tetracalcium phosphate composite TTCP). Sixteen teeth were stored in demineralized solution for two days then examined by SEM. All treated teeth were stored in a glass bottle in artificial saliva of pH 7 at 37oC for periods 30 days then examined by SEM. Two specimens used as a baseline. 16 teeth were sectioned longitudinally in a buccolingual direction through the middle of restoration after immersed in 1% methylene blue solution for 24h, observation for marginal leakage was done under Stereomicroscope at 10X. Results SEM micrographs of group glass-ionomer showed almost normal enamel surface with numerous mineral deposits. The resin-modified glass-ionomer showed enamel surface exhibits almost normal appearance and has minute mineral deposits. The hybrid composite showed enamel surface irregularities and slight separation between enamel and restoration and Tetracalcium phosphate TTCP showed almost normal enamel surface that occluded by numerous mineral deposits. Conclusions: Tetracalcium phosphate composite and resin-modified glass ionomer, are highest marginal sealing than either hybrid composite and conventional glass-ionomers. Tetracalcium phosphate composite, are more effective at remineralization capacity than other groups.
