Types
Local anesthetic solutions for injection typically consist of:
The local anesthetic agent itself
A vehicle, which is usually water-based or just sterile water
Vasoconstrictor possibly (see below)
Reducing agent (antioxidant), e.g. if epinephrine is used, then sodium metabisulfite is used as a reducing agent
Preservative, e.g. methylparaben
BufferEsters are prone to producing allergic reactions, which may necessitate the use of an amide. The names of each locally clinical anesthetic have the suffix "-caine". Most ester LAs are metabolized by pseudocholinesterase, while amide LAs are metabolized in the liver. This can be a factor in choosing an agent in patients with liver failure, although since cholinesterases are produced in the liver, physiologically (e.g. very young or very old individual) or pathologically (e.g. cirrhosis) impaired hepatic metabolism is also a consideration when using esters. Sometimes, LAs are combined, e.g. :

Lidocaine/prilocaine (EMLA, eutectic mixture of local anesthetic)
Lidocaine/tetracaine (Rapydan)
TACLA solutions for injection are sometimes mixed with vasoconstrictors (combination drug)  to increase the duration of local anesthesia by constricting the blood vessels, thereby safely concentrating the anesthetic agent for an extended duration, as well as reducing hemorrhage. Because the vasoconstrictor temporarily reduces the rate at which the systemic circulation removes the local anesthetic from the area of the injection, the maximum doses of LAs when combined with a vasoconstrictor is higher compared to the same LA without any vasoconstrictor. Occasionally, cocaine is administered for this purpose.
It is mostly used in patients who have limited opening of the mandible or in those that have trismus; spasm of the muscles of mastication. The nerves which are anesthetised in this technique are the inferior alveolar, incisive, mental, lingual and mylohyoid nerves. Dental needles are available in 2 lengths; short and long. As Vazirani-akinosi is a local anaesthetic technique which requires penetration of a significant thickness of soft tissues, a long needle is used. The needle is inserted into the soft tissue which covers the medial border of the mandibular ramus, in region of the inferior alveolar, lingual and mylohyoid nerves. The positioning of the bevel of the needle is very important as it must be positioned away from the bone of the mandibular ramus and instead towards the midline. Intraligamentary Infiltration
Intraligamentary infiltration, also known as periodontal ligament injection or intraligamentary injection (ILIs), is known as "the most universal of the supplemental injections". ILIs are usually administered when inferior alveolar nerve block techniques are inadequate or ineffective. ILIs are purposed for:
1. Single-tooth anesthesia
2. Low anesthetic dose
3. Contraindication for systemic anesthesia
4.