Images Of Canine Ringworm Canine Tooth Exposure. Any Information Would Be Helpful?

Canine tooth exposure. Any information would be helpful? - images of canine ringworm

http://www.xemax.com/osc/images/Patient_Education/CLPEMB.jpg

In this photograph of the tooth, the dentist outside the hole is cut. How come tooth in place, without the gum? Moreover, what happens to the hole?