Please see the attached before and after repotting my dracena plant. After a week of the plant looking wilted, I added root stimulator to help. Its been another week and it appears the plant is getting worse. Before repotting I did try to dry it out for easier transplanting, but it did not help. There is calcium build up in the soil, about a cups worth. I have added a significant amount of water to rehydrate the plant. Call or email for additional information or questions. I've had this tree for 9 years and I'd hate to see him (named Junior) go.
Dracenas should be repotted into a pot only one size larger that the previous pot. We can't say for sure from your photos, but if the pot is substantially large than the old one, that could be an issue. (Because the plant cannot use up the water in the soil fast enough, and sitting in soggy soil can rot roots.)
On the other hand, dracenas should never be in dry soil. During the growing period (about spring to early fall), the soil should be thoroughly moist at all times. In winter, it still should not dry out but cbe barely moist. The top inch can dry out between waterings. When you water, saturate the soil and let the excess drain out the bottom. A completely dry soil will shrink and actually repel water. Stick you finger way into the soil to be sure the water is getting absorbed all through the pot.
Finally, we assume you used new potting soil. The calcium you mentioned should have been scraped off and discarded.
It may be that the roots died when you dried out the plant before repotting. Water your plant thoroughly. We hope it rallies.