Converse of object

• need: The dentist took an x-ray, made an immediate diagnosis, and told him he needed a root canal.

Modifies a noun

• treatment: Root canal treatment is a technique which focuses on the treatment of the inside of the tooth.

• therapy: METHODS: Thirty patients receiving non-surgical root canal therapy were studied.

• system: The root canal system is cleaned to remove infected, inflamed and dead tissue.

• work: Had left upper and lower jaw wisdom teeth extracted and molar which had previous ' expensive ' root canal work.

• filling: During that period, L carried out seven root canal fillings and crowned a number of teeth.