Hi doctors, can you tell me what is having a rubber dental dam like?

Protects dental work. Dental dams are used to protect the adjacent teeth ; to keep the area free from saliva when a dentist/dental specialist is working. Materials used for root canals especially cannot be contaminated with saliva (due to bacterial content), so a rubber square dental dam is placed in the mouth ; securely held in place usually by the tooth behind the one being worked on. Saliva is suctioned out under.
Its comfortable. It makes getting a filling or root canal more comfortable as isolates what is being done on the tooth from the rest of the mouth so not only keeps saliva from the tooth while its being worked on but prevents the patient from tasting the materials used during the procedure.