Dental post can be used to support tooth before crowning. how does it work?

Reinforcement: A post placed in a tooth before a crown is placed transfers biting forces down into the root of the tooth, taking stress off the coronal portion.

Retain the crown: A post is placed in a tooth where most of it has been lost to decay or fracture and you will need additional material for a crown to anchor on to. The post anchors the core material that in turn anchors the crown. In this way the crown stay on the tooth better. The post gives not additional support to the tooth. The support is provided by the crown.

Reinforcement: Following root canals, the structure left after root canal can be limited. A post can help not only add reinforcement but also build-up the structure of the crown for crown placement.

Builds it up: A tooth that has had a root canal and is lacking in adequate tooth structure above the gumline can have a post to create enough for a crown to hold onto.

Dental post: is often used to stabilize a weakened tooth after root canal and provide an anchor for a permanent crown.