I have a red line around all my gums for a few years. I assumed this was some gingivitis, but is it? It is read inflamed line or border around the gums, but without tendency to bleed. I have 4 crowns. I am wondering whether it is an allergy. No pain, and involving the gum margin front and back of all teeth, except incisors.

You can have a periondoantal disease without bleeding. The red line around your gum line could mean you have pockets under the gum line, irritating the tissue. These are normally measured (to indicate any problems) when you have periodic cleanings, say every 6 months.

Red gums generally indicate inflammation. Inflammation is caused when bacteria isn't being removed thoroughly on a daily basis.

Crowns can hold bacteria easily at the gumline since this is where the crown and tooth actually meet. When brushing this area use an ultra soft toothbrush, angle the bristles toward the gums and gently insert the bristle tips between the teeth and gums. Giggle the bristles (don't scrub) and then roll the brush down or up depending on the direction the bristles are.

Dipping your toothbrush in a mix of 5 drops of high quality Tea Tree Oil and 1/2 cup of water while brushing this area should help it pink up quickly. Be sure to floss this area well too. You may find that you get a little more bleeding for the first few days since this technique may get below the gums better than what you have been doing.