Remedy for separation between crown margin and gum?

The best solution for this would be to have the crown replaced with one that meets the margin of the gumline.  If this is not an option for you, you could ask your dentist to put a composite filling at the top of your crown, but this composite will easily stain and need to be replaced from time to time.  Good luck and I hope this helps. Follow me if you have more questions.Sarah Thompson, DMDReal Self 100

There can be three different issues with this:One, where there is a visible junction between the crown and the gum. In the past old ceramic crowns made over a white gold core, this could give the look of a black line. With those older crowns it was highly unaesthetic, but often functional, meaning it looked bad, but the crown actually was sealed properly.With current all ceramic crowns, in some cases you can see where the ceramic ends and the edge of the tooth starts. Currently, we try to place the edge of the crown margin right next to, but often slightly above the gum line. For most instances, it's still very aesthetic. Some patients can look and see the color shift. Again, typically the margin is sealed and it is a slight cosmetic compromise to avoid gum damage.Two, in these situations there can be either a black line, brown line or even a difference in the white colors at the edge of the tooth and the crown. This can be a cavity, a loss of the water-tight seal of the crown, a root cavity or an improper fit of the crown. These are all bad and all need attention. Most often it means taking off the old crown, cleaning the underlying tooth properly and then making a new crown. Occasionally  some of these can be repaired by cleaning out the cavity and filling it with matching composite bonding. They often look adequate, but sometimes there is still a very visible color shift. IF it can be repaired, then the less-than-exact color match is a compromise to having to pull off the crown and make a new one.Three, sometimes the crown and tooth margin is fine initially. Over time some people can have some gum recession and then either more tooth edge shows, or the edge of the root shows. Sometimes it can show an obvious mismatch of colors or materials. Usually this is more like the first category above: unaesthetic, but still properly fitting. If there is a lot of gum recession, then you may need to have the gum repaired or grafted (but that is a different topic).Finally, these are general descriptions of what MIGHT be happening with your situation. The best answer is to have it checked (we take photos so we can both look at it with magnification) and then you'll know if its a aesthetic issue or a real problem.