Local anesthesia is the cornerstone of modern endodontic procedures, especially in the treatment of irreversible pulpitis and root canal therapy.
While conventional anesthetic techniques are effective in many cases, endodontists still face significant challenges—particularly in achieving profound pulpal anesthesia in mandibular molars affected by inflammation.
Studies reveal that the inferior alveolar nerve block (IANB), the most widely used technique, can fail in up to 80% of cases with symptomatic pulpitis due to altered nerve thresholds, inflammation-induced acidosis, and anatomical variability.
The past seven years have seen substantial advances in anesthetic agents, injection techniques, buffering systems, and supplementary approaches.
These innovations aim to improve anesthetic success rates, reduce patient discomfort, and enhance the clinical experience for both patients and practitioners.
1. Techniques and Challenges in Endodontic Anesthesia
The inferior alveolar nerve block (IANB) remains the primary method for achieving mandibular anesthesia.
However, its success is highly variable in inflamed pulp tissue. This has prompted exploration into alternative techniques:
✔ Articaine buccal infiltration has shown promising results, particularly in mandibular molars, though meta-analyses show mixed statistical significance when compared to IANB.
✔ Intraosseous injections offer rapid onset and higher success in difficult cases but require special equipment and training.
✔ Gow-Gates and Vazirani-Akinosi blocks provide anatomic alternatives with similar success rates but are technique-sensitive and less commonly used in routine practice.
When IANB fails, supplementary injections such as intraligamentary or intraosseous approaches significantly improve the probability of achieving effective anesthesia.
► DENTAL BOOK: Cohen’s Pathways of the Pulp – 12th Edition (2020): The Ultimate Guide in Endodontics
2. Comparing Anesthetic Agents: Articaine, Lidocaine, and Bupivacaine
Recent evidence highlights the efficacy of newer agents over traditional lidocaine:
✔ Articaine (4%) has demonstrated superior anesthetic performance in several trials. A 2021 meta-analysis showed articaine is 2.17 times more likely to result in successful anesthesia than lidocaine across all injection types. In mandibular block and buccal infiltration, articaine outperformed lidocaine in both success rate and duration.
✔ Bupivacaine (0.5%), known for its extended duration of action, is especially effective in long or complex endodontic procedures. One randomized controlled trial showed a 76.7% success rate with bupivacaine in patients with irreversible pulpitis, compared to 40% with lidocaine.
3. Enhancing Success Rates: Adjunct Strategies
Endodontists have developed several clinical strategies to enhance the success of local anesthesia:
✔ Increased volume: Using 3.6 mL instead of 1.8 mL of anesthetic has shown to improve the success of IANB in challenging cases.
✔ Buffering agents: Alkalinizing lidocaine (with sodium bicarbonate) increases its diffusion and onset speed.
✔ Warming the anesthetic and slow injection techniques have been associated with reduced pain on administration and better diffusion.
✔ Preoperative analgesics (NSAIDs, corticosteroids) may reduce pulpal inflammation and improve anesthetic efficacy.
► Read also: Endodontic Posts in Primary Teeth: A Comprehensive Review for Pediatric Dental Practice
4. Safety and Patient Considerations
✔ Articaine is safe for routine use in endodontics, with rapid metabolism and minimal systemic toxicity. It is contraindicated in patients with known allergies to amide-type anesthetics or sulfonamides.
✔ Bupivacaine provides extended analgesia but may result in prolonged postoperative numbness, which could be uncomfortable for patients.
✔ Intraosseous techniques should be used with care, as they may cause localized bone trauma if performed improperly.
Proper selection of anesthetic technique and agent based on patient-specific factors—such as pulp status, anxiety, and systemic health—is crucial for predictable outcomes.
Conclusion
IANB remains a fundamental technique in endodontics, but its limitations in inflamed tissues require clinicians to consider alternative or supplemental approaches.
Articaine has emerged as a more effective alternative to lidocaine in both mandibular and maxillary procedures.
Bupivacaine offers significant advantages in longer procedures or for extended postoperative pain control.
Adjunct strategies such as increased volume, buffering, or preoperative medications can optimize anesthetic outcomes.
A tailored, evidence-based approach ensures patient comfort and clinical success in modern endodontics.
📚 Key Scientific References (2017–2024)
- Saudi Endodontic Journal 11(3):p 277-282, Sep–Dec 2021. Most effective local anesthetic technique for mandibular posterior teeth with irreversible pulpitis.
- BDJ Open volume 7, Article number: 27 (2021). Articaine in dentistry: an overview of the evidence and meta-analysis of the latest randomised controlled trials on articaine safety and efficacy compared to lidocaine for routine dental treatment.
- Eur Endod J. 2020 Jun 11;5(2):68–72. Determination of Anesthetic Efficacy of Lidocaine Versus Bupivacaine in Single Visit Root Canal Treatment.
