Intrapulpal Anesthesia: Indications, Advantages, and Techniques

Introduction:

Effective anesthesia of vital pulp tissue existing in the pulp chamber or root canals during endodontic therapy is critical for patient cooperation and comfort. There is a requirement to identify consistent, effective ways of achieving pulpal anesthesia during the treatment of root canals. Since these procedures incorporate vital pulp tissue, sometimes there is an absence of pulpal anesthesia despite administration through a block, infiltration, or a supplemental technique such as intraosseous or periodontal ligament injection. To access the chamber and extract the pulp, profound anesthesia is necessary. If the patient experiences pain, the Intrapulpal injection may be utilized as an adjunct to pulpal anesthesia.

What Are the Factors to Consider for Successful Intrapulpal Anesthesia?

• The most crucial factor determining Intrapulpal injection’s success is that its administration must be done under extreme pressure.

• Monheim has proposed that prolonged pressure may cause nerve fiber degeneration, resulting in deep anesthesia in many cases.

• In their clinical trial, Rosenberg and Birchfield reported that the anesthesia effect of the Intrapulpal injection was owing to the solution's back pressure and did not depend on the type of anesthetic drug administered.

• Investigations have established the existence of alpha-adrenergic receptors in the pulpal blood vessels. Such receptors can cause vasoconstriction in response to low levels of epinephrine.

• Olgart and Gazelius discovered that subperiosteal periapical epinephrine injections cause ischemia of the local pulp tissue, which ultimately results in a significant reduction in the number of action potentials formed by pain-eliciting stimuli. They stated that sensory receptors necessitate normal regional blood flow to remain sensitive.

What Is the Role of an Anesthetic Solution in the Intrapulpal Injection?

• According to Malamed, the anesthetic solution may be responsible for the anesthesia caused by the Intrapulpal injection. He claims Intrapulpal anesthesia is induced by the anesthetic solution combined with applied pressure.

• However, as a less desirable alternative, he suggests that an anesthetic solution be deposited inside the pulp canal and that anesthesia is produced solely by the chemical actions of the anesthetic solution.

• As per Nevin and Paustenbaugh, pressure anesthesia is a technique of forcing an anesthetic into the pulp through mechanical pressure just before the extirpation of the pulp. Due to the higher solubility of the Procaine, they claim that the use of Procaine instead of Butethamine produces better outcomes. They also stated that epinephrine should always be combined with anesthetics because it prolongs the duration of the anesthesia.

• According to Ingle, the anesthetic concentration plays a significant role in achieving anesthesia. For example, when a small bur entrance is created into the coronal pulpal chamber, he discovered that two percent of Lidocaine with epinephrine 1:50,000 produces the best results. The anesthetic can then be forced into the pulp under pressure.

• According to Gurney, the best results are obtained with a ten percent Lidocaine solution, which is superior to a two percent Lidocaine solution.

• Smith and Smith concluded that some form of back-pressure is required to force the anesthetic solution throughout the pulp. The pressure alone or in combination with the local anesthetic then produces anesthesia.

What Are the Indications for Intrapulpal Anesthesia?

• The Intrapulpal injection technique is most commonly used in teeth with systematic irreversible pulpitis that has not responded to all other supplemental methods (for example-buccal and lingual infiltration and periodontal ligament injection).

What Are the Advantages of Intrapulpal Anesthesia?

• The Intrapulpal injection technique has many advantages, including the fact that it is technically simple.

• The Intrapulpal injection can deliver more profound anesthesia when administered under back pressure.

• There will be no waiting period, and no special syringes or needles are needed. Intense back pressure has been observed to play a significant role in the production of anesthesia. Passively depositing anesthetic into the pulp chamber is insufficient; the solution will not diffuse throughout the pulp.

What Are the Drawbacks of Intrapulpal Anesthesia?

• The main disadvantage of the technique is that the needle is inserted and injected directly into a vital and extremely sensitive pulp; the injection can be moderate to severely painful.

• Miles stated that there was a drop in the confidence level of the endodontist, and more concerned.

• The duration of pulpal anesthesia may be brief (15 to 20 minutes). However, to avoid the reoccurrence of pain during instrumentation, a significant chunk of the pulpal tissue must be quickly removed and at the proper working length.

• Another disadvantage is that the pulp must be subjected to allow direct injection. Anesthetic problems frequently happen before exposure while still in dentin.

How Is Intrapulpal Injection Given?

• Clinicians should utilize a small round bur to make an opening into the pulp chamber that is large enough to guarantee a tight fit of the needle. If the entrance to the pulp chamber is already large for needle binding, a stoppering technique (the cotton pellet over the needle) was used. Then, the needle should be introduced into the pulp chamber until a close fit is accomplished. A standard anesthetic syringe with a 25, 27, or 30-gauge needle was used for injecting the anesthetic solution. If resistance is experienced, 0.2 milliliters of anesthetic solution should be injected into the root canals. Pulpal anesthesia can be instant after an Intrapulpal injection.

• The Intrapulpal injection procedure can cause moderate to severe pain, resulting from pulp exposure before anesthetic administration and the injection process itself.

• If an Intrapulpal injection is not possible or all other supplemental injection strategies (such as intrapulpal and intraosseous injection) fail to achieve profound anesthesia, a repeat appointment with premedication may be recommended to improve patient comfort and anesthetic efficacy.

Conclusion:

Intrapulpal injection is a standard supplementary injection method used to achieve pulpal anesthesia in teeth where the primary anesthetic technique cannot produce profound pulpal anesthesia. The Intrapulpal injection technique has many advantages, including the fact that it is technically straightforward, does not necessitate rubber dam removal, and has negligible systemic side effects. Furthermore, any solution injected with back pressure can produce anesthesia. The main disadvantage of this technique is pain.