Introduction
It is natural that a patient usually expects a painless dental treatment that would enhance their comfort while undergoing an oral surgical or dental procedure. This is of even more crucial importance to those patients who suffer from dental fears and anxiety (dental phobias). Also, the confidence of the patient is equally dependent upon the ability or the skill of a dentist or oral surgeon himself for the primary target of achieving adequate profound and successful local anesthesia prior to the procedure and pain relief post-surgery.
What Is the Scope of PDL Intraligamentary Injection?
Periodontal ligament injections are shown to have success rates upon proper operator tactility with this approach. In this approach, the dentist inserts the tip of the needle into the periodontal ligament between the root surface and the alveolar bone. This technique is often associated with specificity reported from 58 % to 100 % with higher success, especially for periodontal treatment and extraction procedures, as compared to less efficacy in endodontic procedures (less effective for deep-rooted infections).
The injection technique of PDL offers the patient and dentist multiple advantages. Postoperative restrictions for speaking, eating, drinking, etc., do not exist for patients following dental treatment under ILA (intraligamentary local anesthesia). Simultaneously, this technique prevents postoperative bite or burn injuries that are a consequence of prolonged sensitivity loss after major or potent anesthetic techniques like PSA and IANB.
When Is Intraligamentary Injection Used as an Alternative?
Though there exist many different anesthetic techniques depending upon the region of the oral cavity to be anesthetized (for example, the posterior superior alveolar nerve block for anesthetizing maxillary molars, premolars, and the IANB (inferior alveolar nerve block) for anesthetizing mandibular molars). The most common techniques remain infiltration anesthesia (IA) as well as the inferior alveolar nerve block (IAN).
In the IANB technique, the pain perception pathway is interrupted at the area of injection that is related to the innervation area of the mandibular nerve. Similarly, any anesthetic technique's goal remains beside the interruption of pain perception, the potential to block the function of sensory and motor nerves in the region to be anesthetized.
The inferior alveolar nerve block for lower jaw anesthesia mainly relies on depositing solution close to the inferior alveolar nerve (prior to the nerve's entry into the mandibular foramen). The landmarks for this technique are the greatest concavity of the coronoid notch, the internal oblique ridge, and the depression of the pterygomandibular raphe. By syringe orientation over the opposite-side premolars at an angle parallel to and above the occlusal plane of the mandibular molars, the needle tip is inserted till the bone is in contact directly. However, the success rate of this IANB technique depends upon patient sensitivity, the extent of dental or oral infection, operator tactility, and technique sensitivity as well. So when this nerve block fails to produce the desired effect, that is when the application of this block is unsuccessful, clinicians may either choose to repeat the inferior alveolar block or opt for the intraligamentary technique as a reliable option to achieve profound anesthesia.
Clinical research and trials have shown the effectiveness of the intraligamentary technique over-tested and alternate techniques, such as the Gow-Gates nerve block (which does not have reported success rates of 100 % anesthesia during the procedure). Although local anesthesia failures can be due to multifarious causatives, the majority of inferior alveolar nerve block failures can be possible in two ways, either due to the ineffectiveness of blockade of the inferior alveolar nerve and the second possibility arises when accessory innervation provides at least some sensation to the mandible (lower jaw) and the dentition in spite of potent anesthesia. Hence for these regions, a successful single-tooth periodontal ligament injection can be administered wherein the sensory input is effectively prevented for the duration of the dental procedure.
What Are the Types of Tissue to Be Anesthetized?
Type I Low-Density Tissue: Usually found in buccal mucosa where anesthetic solutions diffuse with less or very minimal pressure.
Type II Moderate-Density Tissue: This is found in attached gingival and palatal tissues that are less flexible and where moderate pressure is required for diffusion of anesthetic agent.
Type III High-Density Tissue: Highly inflexible, and tissue resistance is present. Tissue is usually found in the periodontal ligament. Due to the inflexibility in type 3 tissue as compared to type 1 and type 2, the anesthetic solution may be hard to diffuse through the vascular and nutrient canals within the bone socket. Due to the potential for excessive pressures during deposition, periodontal ligament injection rates must be given slowly by the dental surgeon, and site selection should include only those sites that accommodate an easy flow of diffusiveness.
How Is the PDL Intraligamentary Technique Done?
The ILA starts with the dental surgeon's needle insertion into the periodontal ligament space between the tooth root and the alveolar bone. The needle is inserted at an angle of 30 to 40 degrees with respect to the long axis of the tooth. The anesthetic solution should hence reach a subgingival depth of about 2 to 3 mm. Single-rooted teeth must be anesthetized with two injections preferably, and for multi-rooted teeth, with one injection per root to attain efficacy. The injection time for the first application should last a minimum of 20 seconds. Firm, steady pressure with the deposition of the solution slowly given by the dental surgeon along with the correct depth for needle penetration remains important for potent anesthesia with this technique. The dentist need not aspirate as well because the rate of positive aspiration is effectively zero due to the periodontal ligament tissues lacking much vascularity.
How Are Anesthetic Complications Prevented?
Histologic studies show the diffusion of anesthetic solution into the alveolar bone soon after application. This process consumes a bit more time than conventional anesthesia in order to combat tissue resistance. Also, overpressure in the periodontal alveolar bone complex should be avoided. In the case of a hasty injection (often due to iatrogenic errors), extrusion of the respective tooth may be a reported sequela due to hydraulic force exertion. Postoperative pain due to high pressure after the injection, though reported in a few cases due to potential tooth extrusion, described as a complication in literature, can be avoided by the accurate consideration of the injection features, especially the injection time by the dental surgeon.
Conclusion:
Thus the periodontal ligament injection technique, when followed by the dentist correctly, can produce effective anesthesia with fewer postoperative restrictions to the patient and also can be an alternative when the conventional anesthetic techniques fail initially during the oral surgery procedure.
