The mineral content of dentin is very important in bonding and filling quality. Therefore, measuring the calcium and phosphorus weight percentage after caries removal using chemo-mechanical caries removal agent or erbium chromium laser will lead to a proper guidance for the best bonding protocol could be used. The aim of this study is to evaluate and compare the effect of Selecti-solve, CarieMove and Erbium chromium laser on the remaining mineral weight percentages of dentin of primary molars after caries removal. Fifteen extracted primary molar teeth with occlusal carious dentin were assigned into three groups according to caries removal technique (Group I: Selecti-solve, Group II: CarieMove, Group III: Erbium chromium laser). After, carious dentin removal take place, atomic analysis of treated cavities was performed by energy dispersive X-ray spectroscopy. According to the statistical analysis, For Calcium/ Phosphorus ratio there were no statistically significant differences between the Selecti-solve, CarieMove, and Erbium Chromium Laser groups. CarieMove had the highest mineral content compared to Selecti-solve and Laser. These results will therefore lead to a better bonding capacity and improve the quality of filling afterwards.