My weak spot is the periodontal pockets that run beneath the gum, and the tooth on the surface is fine, but the tooth on the inside where the gum deteriorates is not. The interior is hollow, and the hard tissue softens, causing the tooth to disintegrate and collapse. On the exterior, there may be rot, but that is all. I lost three teeth in this manner and went to https://perfectasmile.com/ to find out what I should do. They recommended that I have portions of the tooth removed and implants placed instead of the cavity so that I can have teeth till I'm 30. When you don't pay attention to the condition of your teeth, you may believe that everything is alright. In fact, it's dreadful.