dental crowns

[maypole]

Why do you get a dark line between gum and crown when you have a tooth capped?:confused:

[angel]

If it's an old crown then it could be gum recession or that the white of the crown is wearing away with age.

[maypole]

Thank you angel, so am I to assume that it should not happen as a matter of course?

[angel]

I'm just suggesting what it might be, I'm certainly no expert. Toothsmith will probably be along soonish to give some proper advice! How old is the crown?

[mda99das]

What you have to remember is that to date there is no restorative material that has all the properties of human teeth.

Every cap no matter how well made will ALWAYS have a gap between the tooth and the crown. We may be talking a few microns but its still there.

Gum recession can be

as a result of trauma, gum disease, dehissence etc etc.
The gaps at the crown margin may be enough to cause chronic irritation to the gum causing it to recede.

[Toothsmith]

Why do you get a dark line between gum and crown when you have a tooth capped?:confused:

Another reason is due to the way light passes through the tooth.

Crowns with a metal base will not allow any light through at all, and so the bit of tooth at the bottom of the crown will look very dark.

Modern ceramic materials are much better at this, having refractive indicies very close to enamel, but even so, it takes a very skilled preparation, and a good technician to get it looking really good.

[MoaningMyrtle]

My denitist told me it is the metal base of the crown. I've got one where it is a bit too proud and you can just see the thin line of metal.

I've got to have another one now, £176 for a gold NHS one or £400 for a white Private one. I've just started saving.

[angel]

I've just had a new ceramic crown made, it was amazing. My wonderful dentist designed it right there in front of me on the screen and explained how it has to fit. Then we went out the back and put the ceramic block into the machine and it buzzed away for 20 minutes and out popped a very sweet crown! Even though it's at the back I keep showing people how realistic it is, it even feels like a real tooth.

[maypole]

My crowns are a good few years old, they are either side of my two front teeth, which seem to be getting shorter as I get older, I am tempted to have my front teeth crowned, after hearing that veneers might need changing after a few years. I hate having to deal with tooth problems :eek: and a bit scared to start clarting about with healthy teeth.

Thank you for all your replies though :T