The tooth has a complex structure, it has two anatomical parts; the crown and the root. The crown is normally visible in the mouth (above the gum line). The shape of the crown determines the function of the tooth. The root of a tooth is the part embedded in the jaw. It anchors the tooth in its bony socket and is normally not visible (below the gum line). The gum line is where the tooth and gums meet. The periodontal ligament is responsible for attaching the tooth to the jaw bone. It is made up of thousands of fibres which fasten the cementum to the bony socket. These fibres anchor the tooth to the jaw bone and act as shock absorbers for the tooth, which is subjected to heavy forces during chewing. Tooth pulp is originating in the center of the tooth, underneath the enamel layer (the top layer) and the dentin layer (the second layer), in the pulp chamber. Tooth pulp is soft and consists of living blood vessels, connective tissue, and large nerves. Also commonly referred to as the nerve, the pulp branches out and continues down each root through the canals of the tooth and stops just shy of the apex, or tip, of the tooth. There are plenty of conditions causing extreme, growing, sharp, shooting, or throbbing tooth pain originating from nervous stimulus. Among them are pulpitis (pulpal inflammation) and abscess formation. Dental (periapical) abscesses are an acute infection of the periapical tissue around the root of the tooth. Dental caries result in damage to the tooth enamel, which allows bacteria access to the dental pulp. From here the infection spreads down the root canal and out of the apical foramen where abscess formation occurs. Dental abscesses can exert pressure on the root of the tooth, which contains the neurovascular bundle, and can lead to devitalisation of the tooth.
Does this mean that he can't feel anything in that particular spot? So the entire "tooth hole" is numb?
No...the pulp only innervates the tooth...the gum has it's own innervation. This allows all sensation to be felt, thereby minimising trauma (e.g. hot/cold --> burns, sharp food/objects --> punctures/abrasions....etc)
Not exactly if you have luck yes if not you have a lot of pain because of the lose nerves