1、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
2、 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,
3、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 n
4、o 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
5、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
6、 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) Injectio
7、n,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. Specific analgesia to isolated teeth. Single mandibular tooth can be anesthetised without performing a pterygomandibular bl
8、ock. This avoids numbness of the lip and tongue. There is less likelihood of inadvertently traumatising these structures in the immediate post injection phase. iii. Useful adjunct to conventional local anesthesia; and in experienced hands for minor surgical procedures. - Disadvantages: i. Post injec
9、tion discomfort due to temporary extrusion. ii. Apparent increase in the incidence of “dry socket“.,Technique,Needle: 25-gauge is recommended. The local anesthetic solution is injected along periodontal membrane of maxillary and mandibular teeth, using small amounts of local anesthetic solution, usu
10、ally 0.2 ml, delivered via a specifically designed system, which comprises of high pressure syringes and ultrafine needles. The high pressure forces the solution rather than causing diffusion, through the periodontal ligament to the nerves in that area.,Intrapulpal Anesthesia,This technique is indic
11、ated for obtaining anesthesia for procedures which require direct instrumentation of the pulpal tissue. First, put a cotton ball soaked in local anesthetic solution in the cavity, wait for a minute; and then a 25 or 27-gauge needle is inserted directly into the pulp chamber. The needle should be hel
12、d firmly or wedged into the pulp chamber or the root canal. Initially, slight discomfort is felt by the patient which subsequently gets subsided. Sometimes the needle is bent to get a proper angle for good approach,Intraosseous Injection Technique,In this method, the local anesthetic solution is dep
13、osited directly into the cancellous bone adjacent to the tooth to be anesthetised, between the two cortical plates of bone of maxilla and mandible. Intraosseous injection is usually an adjunct, and is used when conventional methods have been tried and failed.,Technique,The soft tissues overlying the
14、 apex of the tooth are first anesthetised with paraperiosteal injections. This injection should be made either mesial or distal to the tooth to be anesthetised, and slightly above the roots, in order to avoid injury to the teeth,Intraseptal Anesthesia,It is considered as a variation of intraosseous
15、anesthesia. A needle is forced gently into the porous interseptal bone on either side of the tooth to be anesthetised,Local Infiltration of the Palate,The anesthesia of the hard palate is necessary for dental procedures involving manipulation of palatal soft and hard tissues. The palatal injections
16、are one of the most painful injections. It is advisable to inform the patient prior to injection about the pain during the injection. This helps in preparing the patient psychologically.,Nerves anesthetised: Terminal branches of greater palatine and nasopalatine nerves. Areas anesthetised: Soft tiss
17、ues and bony hard palate in the vicinity of the injection.Indications: Anesthesia in a small area of injection. Hemostasis in the area of surgery. Contraindications: Presence of acute inflammation or infection at the site of surgery. Provides a small area of anesthesia.,Technique,Needle: 27 or 3D-ga
18、uge needle is usually recommended, however, 25-gauge needle can also be used. Point of insertion: In the mucoperiosteum on a line 1 cm from the gingival margin, or midway between the gingival margin and the median palatine raphe. Target area: Mucogingival tissues in the area of injection. Anatomical
19、 landmarks: Mucogingival tissues in the vicinity of the area to be injected.,The needle is inserted into the tissues from the opposite side at an angle of 45 to the bony surface of the palate.,Complications,Sloughing and ischemic necrosis: It is seen when a local anesthetic agent with highly concent
20、rated vasoconstrictors are used; and in excessive amount. Hence do not inject more than 0.5 ml at any one injection site; or stop as soon as blanching of the tissues occurs.,Field Block,A field block, as the anesthetic solution is deposited at or above the apex of the tooth to be treated. This metho
21、d is the most preferred method for all the teeth except the lower posterior teeth.,Nerves Anesthetised Terminal nerve branches in the vicinity of the area to be anesthetised. Areas anesthetised The areas anesthetised by the field block will be larger and circumscribed. These areas include the pulps
22、of the teeth and the tissues distal to the site of injection, which comprises of the supporting alveolar bone, buccal periodontium and overlying soft tissues.,Difference between Field Block and Nerve Block,The difference in the field block and the nerve block is basically the extent of anesthesia ac
23、hieved or the nerve terminal anesthetised. Field block is more circumscribed, involving tissues in and around one or more teeth. The nerve blocks involve a larger area, as they involve a larger terminal nerve, along the course of the nerve, such as seen following pterygomandibular block.,Indications
24、 Contraindications,All maxillary teeth Mandibular anterior teeth.Contraindications Presence of acute inflammation or infection at the site of injection. Mandibular posterior teeth. The alveolar bone in the region of mandibular bicuspids and molars is usually thick and dense to permit diffusion of th
25、e local anesthetic solution.,Technique,The local anesthetic solution is deposited near the larger terminal nerve branches. Technically speaking, all the injections given above the apices of all maxillary teeth to achieve anesthesia should be considered as field blocks. The examples are maxillary injections administered at or above the apices of the teeth.,
