The Effect of Mineral Composition Contents on Cracks Formation of Teeth Subjected to Er, Cr: YSGG 2780 nm Laser Irradiation

Objective: The aim of this study was to investigate the relation between dentinal cracks and dentin mineral contents after irradiation with Er, Cr: YSGG laser. Settings and Design: Average power was 3.75 W, the frequency was 15 Hz, 30% water, 60% air, the energy density was 31.84 J/Cm-2. Material and method: Ten teeth of single canals were biomechanically prepared and obturated then the root end was resected using carbide cross cut bur at 0 degrees bevel. The retrograde cavity was prepared using Er, Cr: YSGG 2780 nm laser delivered through MZ6 glass tip of 660 mu m diameter. Samples were prepared for SEA4 and examined to evaluate dentinal cracks then examined using Energy dispersive X-ray spectroscopy (EDX) which was performed to measure the mineral contents of dentin at the retrograde cavity. Results: High fluctuation of dentinal cracks' occurrence from absence to 7 cracks. Conclusion: EDX showed no correlation between the occurrence of dentinal cracks and the weight % of Ca and P within the dentin in the retrograde cavity.