My wisdom teeth have been "erupting" for over 4 years now and none of them has surfaced. Is this ok?

Dentist. See a dentist for an x-ray (panoramic x-ray that should show all the wisdom teeth,) and have a consultation on options.
Wisdom teeth. They may be impacted or partially impacted. You should get a consultation with an oral surgeon for evaluation. These types of scenarios can some times lead to an infection.
Depends. Depends on the circumstances. Impacted wisdom teeth can compromise the health of the adjacent teeth. Gest expert advice. For best results with wisdom teeth, make sure you are evaluated and treated by a board certified oral & maxillofacial surgeon.
Probably not. Most of the time wisdom teeth do no erupt & can cause pain when they are poorly aligned or impacted. Abnormal positioning of wisdom teeth can also of crowd or damage adjacent teeth by making those teeth more vulnerable to decay by collecting food particles and harboring bacteria, and/or pressing on the nerves in the jaw. Many people need their wisdom teeth removed in their late teens or early 20s.