The purpose of this study were to examine the effect of 4-META/MMA-TBB resin containing calcium chloride dihydrate (CaCl₂) on dentin remineralization and its mechanical properties. Different percentages of CaCl₂ (5%, 10%, and 30%) were added to 4-META/MMA-TBB resin. The Ca²⁺ released from CaCl₂ bound to the phosphoprotein formed hydroxyapatite crystals to initiate dentin remineralization in 5%, 10% and 30% CaCl₂ groups in vitro dentin mineralization system. Mineral induction time decreased with increasing of CaCl₂ concentration in the resin. Vickers hardness and bending strength of 5% CaCl₂ group were significantly higher than other groups. The results of elasticity analysis for the control, 5% and 10% CaCl₂ groups showed no significant difference, and the viscosity analysis showed no significant difference between 4-META/MMA-TBB resin with up to 10% CaCl₂ and the control.

The 4-META/MMA-TBB resin with 5% CaCl₂ showed dentin remineralization activity with good mechanical properties.

The purpose of this study was to evaluate the effects of direct pulp capping on hard tissue formation by using alginate gel (AG) containing bone morphogenetic protein-2 (BMP2). Cavities with the exposed pulp areas were prepared on Wistar rats molars and were covered with AG containing BMP-2. Experimental sites were divided into two groups according to whether or not BMP-2 (0.1 µg/µL) was contained in AG. Then they were sealed with 4-META/MMA-TBB resin cement. In both groups, the covered materials were observed at one week after operation. At four weeks, they had disappeared, and the hard tissue formation was observed. Thickness of the hard tissue formation of AG containing BMP-2 group was significantly higher than that of AG without BMP-2 group (P < 0.05). These results suggest that AG containing BMP-2 has effects on hard tissue formation in the case of direct pulp capping.