I had my front upper six teeth prepared for crowns for cosmetic purposes. I had no infection or any other problem besides growing gaps between teeth. So I thought I'd go for "smile design". But ever since these teeth underwent preparation and treatment they have been bleeding ever so occasionally with constant dull ache. And the bleeding is profuse, not like infected teeth. My whole tooth-brush gets covered in blood. I got checked for infection several times, evengot X-ray scanned, but my doc says there's no infection, yet they bleed. Please tell me a solution and reason for this.