When a tooth is beyond normal restoration, a pulp therapy is required and endodontics involves the different pulp treatments that a tooth can receive to deal with infection.
These are procedures indicated for younger patients. Deciduous teeth are a lot different from permanent teeth so their needs are different too.
Basic oral surgery involves the removal of teeth, but when the tooth is impacted or embedded within the bone, an odontectomy is prescribed. There are other surgical procedures that can be performed by an oral surgeon.