Infiltration anaesthesia is the local elimination of pain in a tissue by local infiltration of a local anaesthetic. After injection of the local anaesthetic, the active substance is distributed by diffusion between the tissue gaps and thus reaches the nerve fibres.
Standard dentistry procedure for anaesthesia of maxillary teeth:
In infiltration anaesthesia, the local anaesthetic is injected directly into the tissue in the area of the operation. The effect is based on blocking sensitive nerve endings and terminal nerve tracts. A small amount of anaesthetic is infiltrated into the root tip area of the corresponding tooth and then penetrates the bone to the tooth (root tip), so that the tooth is also anaesthetised.
Infiltration anaesthesia is not suitable for anaesthetising the lower teeth, as the outer bone wall is too compact and the anaesthetic cannot penetrate deep enough. Infiltration anaesthesia changes the properties of the tissue to be operated on and also requires relatively large amounts of local anaesthetic.
A special form of anaesthesia is intradermal anaesthesia ("skin paddle"), because with intraoral infiltration anaesthesia the area to be anaesthetised is infiltrated through one or more punctures in a fan-shaped manner. The anaesthetic solution penetrates the bone, but only anaesthetises the teeth in the entire upper jaw, as well as the front area of the lower jaw.
An infiltration anaesthesia is not suitable for anaesthetising the teeth in the lower jaw area because the outer bone wall is very compact. The anaesthetic is not able to penetrate the wall of the alveolus sufficiently. Infiltration anaesthesia is only used in the upper jaw area.