As long as it hurts in hot and cold water, it means that the defect is not big, and the pulp is still alive and can be completely preserved.

Only root canal therapy (killing nerves) can remove necrotic substances and hidden dangers, which is very similar to building a house and laying the foundation first.

Then make a post crown, or directly make a porcelain crown to cover the black part.

None of this will affect your microscopic level, and you can make it with temporary materials every time, which will not affect your work at all.