Injection骨膜下注射课件.ppt

Subperiosteal Injection In this method, the local anesthetic solution is injected beneath the periosteum. Subperiosteal injection has superiority over supraperiosteal injection. Technique Needle: Recommended length and gauge, 25 respectively. The needle is inserted midway between gingival margin and the approximate apex of the tooth; and at right angle to the buccal alveolar plate, in order to penetrate mucous membrane, gingival tissue and periosteum. The needle is then placed at an angle of 45° to the alveolar plate, bevel facing the bone and then it is advanced towards the apex of the tooth, beneath the periosteum. Infiltration-subperiosteal injection in anterior maxilla-the position of the point of the needle is at an angle of 90° to the long axis of the tooth and the alveolar bone as seen from the side. Advantages It is more appropriate, more specific and definite in region. There is no great trauma, contrary to belief. It is safe and much more effective than supraperiosteal injection. Less solution is required to produce the desired results. Total amount of solution sufficient to produce satisfactory and profound anesthesia is 0.3-0.5 ml. The onset of action is rapid. The depth of anesthesia for extraction is achieved immediately, however, for conservative restorative procedures such as preparation of cavities and crowns, and extirpation of pulps, it is advisable to wait for five minutes to allow the solution to reach pulp chamber and anesthetise the neural component. This method greatly reduces the incidence of intravascular administration. Reduces needle punctures. Disadvantages There is theoretical damage to the periosteum. No greater trauma is created by injecting local anesthetic solution beneath the periosteum. Intraligament (Periodontal or Peridental) Injection It is a very efficient method of producing anesthesia especially for cavity preparation, crown preparation, pulp extirpation, etc. - Advantages: i. Rapid onset of action. ii. Spe