3 Major Types of Local Anaesthesia


There are several general methods of obtaining pain control with local anesthetics. The site of deposition of the drug relative to the area of operative intervention determines the type of injection administered. Three major types of local anesthetic injection can be differentiated: local infiltration, field block, and nerve block.


Small terminal nerve endings in the area of the dental treatment are flooded with local anesthetic solution. Incision (or treatment) is then made into the same area in which the local anesthetic has been deposited. An example of local infiltration is the administration of a local anesthetic into an interproximal papilla before root planing.

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Local anesthetic solution is deposited near the larger terminal nerve branches so the anesthetized area will be circumscribed, preventing the passage of impulses from the tooth to the central nervous system (CNS). Incision (or treatment) is then made into an area away from the site of injection of the anesthetic. Maxillary injections administered above the apex of the tooth to be treated are properly termed field blocks (although common usage identifies them as infiltration or supraperiosteal).

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Local anesthetic is deposited close to a main nerve trunk, usually at a distance from the site of operative intervention. Posterior superior alveolar, inferior alveolar, and nasopalatine injections are examples of nerve blocks.

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The type of injection administered for a given treatment is determined by the extent of the operative area. For management of small, isolated areas, infiltration anesthesia may suffice. When two or three teeth are being restored, field block is indicated, whereas for pain control in quadrant dentistry, regional block anesthesia is recommended.