What Would Cause Only 1 Tooth to Stain Much Faster Than the Others? (photo)

Sometimes teeth have the nerves shrink away, called calcific metamorphosis.  This more dense tooth appears more yellow than the adjacent teeth and does not respond well to bleaching.  It MAY mean a root canal is in its future, but the only predictable way to whiten the tooth is with a porcelain crown or porcelain veneer.

It appears in your photo that there might be an old bonded filling on that stained tooth. It could be the old bonding that is staining, and not bleaching like the others.

Hello there,

The reason for discoloration is that you have a very large bonding on that tooth. Because the bonding material is much more porous than your enamel, it tends to absorb stains and pigmentation in food or drinks. You can have it repolished by your dentist and if the problem is frequent, you may want to consider having a porcelain veneer placed on the tooth. Hope this helps.