This invention relates to a negative pressure irrigation system including one or more negative pressure irrigation needles sized for insertion into a canal of a tooth, each needle having a closed distal end and two suction inlet ports located opposite one another immediately proximal to the closed distal end. The needles are placed in communication with a dental vacuum system by way of a suction manifold. An irrigant inlet tube supplies irrigant from a irrigant container into a pulp chamber or a tooth. The irrigant inlet tube may include a tapered end designed to tightly fit into a lateral irrigant supply port previously drilled into the pulp chamber. A light-cure polymer seals the inlet tube and needles when in use.
