Dental Recall Letter For Patients 2 New Dental Crowns Received But Top One Has Boundary Line Showing--is This Normal?

2 new dental crowns received but top one has boundary line showing--is this normal? - dental recall letter for patients

Hello I have just two crowns, one in the upper teeth and one tooth on the front of the mandible. The two are (all Porcelin crowns and are) only a few weeks. The floor has no visible boundary between him and the gumline, while the upper has a visible border (looks like a gray line) in the Porcelin crown ends shortly before the gums. It is set around (I have the mouth mirror upper teeth facing the inside) of the roof of the mouth.
I remember when my dentist my first tooth, it seemed to have a bit of a hurry. Finally, the summit of the crown is not as strong as in the lower range (for example, when I feel bite hard to say something to chew that meat or apple) I am a light train / pressure inside the top ring when I do. Showed soft chew things, no stress. The context of the crown seems to be perfect, and I feel no pressure. The crowns of the dollar costs (including 1,000 each) and both have the same work.
I like the line that shows how to dispel the illusion of a norm al tooth, there are (at the bottom of the crown is perfectly matched to the teeth of aum).

I am not a dentist, but I think that from the bottom-line is visible, either at the top.

My question is, can I tell my dentist to do something (is there any way to the border in full) and resolve any way to remove the tension from time to time I do not feel bite or the crown must be removed and reinstalled installed.