Latest Irrigation Protocols in Endodontics That Improve Root Canal Treatment Success

Buffering local anesthetic by adding sodium bicarbonate to raise pH is becoming more common among dental clinicians aiming for less pain and faster onset.

But does the evidence support making this a routine part of practice?

Well, here is a clinically relevant guide based on the latest research.

The Science of Buffering

Standard lidocaine and articaine cartridges are acidic (pH ~3.5–5.5) to preserve epinephrine.

Buffering with sodium bicarbonate raises the pH near physiologic (~7.4), which increases the non-ionized anesthetic available for nerve penetration. This change reduces the "burn" during injection and accelerates the onset¹.

What Research Shows?

A. IANB in Adults

• Buffered lidocaine achieved faster onset (~48 s) and less injection pain (~5 VAS points) compared to non-buffered options².

• However, the success rates of profound anesthesia remained statistically similar.

B. Buffered Articaine for Mandibular Infiltration

• A 2023 clinical trial (63 volunteers) showed buffered 4% articaine had a significantly faster onset (4.5 ± 1.6 min vs. 6.6 ± 1.6 min, P=0.001) and lower injection pain (7.8 mm vs. 11.3 mm VAS, P=0.001), though anesthetic success was comparable³.

C. Buffered Articaine in Maxilla

• A 2015 trial comparing buffered vs. non-buffered 4% articaine for first molar infiltration found no difference in onset or pain, suggesting tissue variability matters⁴.

D. Pediatric Block in Primary Molars

• Controlled pediatric RCT demonstrated that warmed or buffered 2% lidocaine reduced pain and improved onset/duration in children’s IANBs⁵.

Chairside Buffering: How to Do It?

Manual Mixing (Easy DIY):

• Withdraw about 0.18 mL from a 1.8 mL LA cartridge, replace with 0.18 mL of 8.4% sodium bicarbonate (a 10:1 ratio)⁶.

• Mix gently and eliminate air bubbles before injection.

Pre‑Buffered Systems:

Pre-buffered delivery systems allow chairside buffering of local anesthetics in seconds, without manual mixing or syringe changes.

Tools like OnPharma Onset Pen and Anutra streamline the process by incorporating buffering mechanisms directly and improve efficiency and consistency.

Practical tips:

• Use buffered cartridges within 24 hours, as they degrade faster.

• Always expel air bubbles to prevent any pressure jolts.

• Streamlined with modern devices, buffering adds only 10–15 seconds of chairside time.

When Buffering Makes a Difference?

Final Takeaway

Buffering the local anaesthesia may not guarantee a deeper effect, but it does provide benefits such as faster onset and reduced pain.These benefits are important for inflamed tissues and sensitive patients. Pre-buffered kits offer minimal hassle and position themselves as a smart upgrade for modern practices.

References

1. Senthoor P, Janani K, Ravindran C. A prospective, randomized double-blinded study to evaluate the efficacy of buffered local anesthetics in infected and inflamed pulp and periapical tissues. J Maxillofac Oral Surg. 2019;19(2):246–250.

2. Guo J, Li Y, Wang Y, Deng Y. Comparison of buffered and non-buffered lidocaine in inferior alveolar nerve block: a meta-analysis. J Dent Anesth Pain Med. 2018;18(3):129–142.

3. Roodnick S, Chisci G, Mijiritsky E, Salari A, Shpack N. The effect of buffered versus non-buffered 4% articaine with 1:100,000 epinephrine on mandibular first molar infiltration: A randomized, double-blind, crossover clinical trial. J Dent Sci. 2023;18(3):1047–1054.

4. Shurtz R, Nusstein J, Reader A, Drum M, Fowler S, Beck M. Buffered 4% articaine as a primary buccal infiltration of the mandibular first molar: a prospective, randomized, double-blind study. J Endod. 2015 Sep;41(9):1403–1407.

5. Kurien RS, Goswami M, Singh S. Comparative evaluation of anesthetic efficacy of warm, buffered and conventional 2% lignocaine for the success of inferior alveolar nerve block (IANB) in mandibular primary molars: A randomized controlled clinical trial. J Dent Res Dent Clin Dent Prospects. 2018;12(2):102–109.

6. Malamed SF. Buffering local anesthetics in dentistry. J Am Dent Assoc. 2013 Aug;144(8):867–872.