Clinical Considerations of Intrapulpal Anesthesia in Pediatric Dentistry

Intrapulpal anesthesia in endodontics: an updated literature review

Effective pain management is crucial for the successful performance of various endodontic procedures. Painless treatments are made possible by anesthetizing the tooth to be treated using various nerve-block techniques. However, certain circumstances necessitate supplemental anesthetic techniques to achieve profound anesthesia, especially in situations involving a "hot tooth" in which intrapulpal anesthesia (IPA) is employed. IPA is a technique that involves the injection of an anesthetic solution directly into the pulp tissue and is often utilized as the last resort when all other anesthetic techniques have been unsuccessful in achieving complete pulpal anesthesia. This review focuses on the IPA procedure and the factors that influence its success. Additionally, the advantages, limitations, disadvantages, and future directions of IPA are discussed.

Influence of Lignocaine Hydrochloride with Adrenaline on Free Active Chlorine Content of Sodium Hypochlorite Solution Admixed in Various Proportions

Objective:

Local anaesthetic solution that is commonly employed for supplemental intrapulpal injection (IPI) may routinely come in contact with subsequently used sodium hypochlorite (NaOCl) during endodontic treatment of symptomatic irreversible pulpitis cases. This in vitro study investigated the available free active chlorine (FAC) content of 3% NaOCl after mixing with 2% lignocaine hydrochloride with adrenaline (LA) solution in three different proportions using iodometric titration analysis.

Methods:

Aliquots of 3% NaOCl (control) in different measures (30 mL, 27 mL, 21 mL and 15 mL) served as the effective concentrate of various proportions of NaOCl admixed with the test solutions, i.e., demineralised water (DM) and LA. The mixed aliquots containing NaOCl-DM and NaOCl-LA combination solutions admixed in various proportions (9:1, 7:3 and 1:1 w/v) respectively served as the experimental groups. Iodometric titration was performed to determine the FAC of each independent solution.The results were then evaluated using one-way ANOVA and Tukey’s post hoc analysis to determine the differences between various groups and amongst the individual admixtures. The level of significance was set at P<0.05.

Results:

Inter-group comparisons revealed statistically significant differences (P<0.05) between all the test groups. An intra-group analysis revealed significant differences (P<0.05) in group 2, whereas no differences (P>0.05) were observed in group 3. Further, there was a dose dependent reduction in FAC content in both the experimental groups with lowest FAC values were observed in 1:1 solution admixtures followed by 7:3 and 9:1 proportions.

Conclusion:

There was a significant reduction in NaOCl FAC content when admixed with lignocaine HCl even in small proportions. Hence, adequate measures should be taken to remove the residual LA from the pulpal space, before the use of NaOCl after IPI administration.

A spectroscopic assessment of interaction between 4% articaine hydrochloride with adrenaline and various endodontic irrigants

BACKGROUND

Interaction between 2% lidocaine HCl (with and without adrenaline) and sodium hypochlorite (NaOCl) resulted in a toxic precipitate formation. The aim of this in vitro study was to assess the interaction between 4% articaine hydrochloride with adrenaline (AHa) and commonly used endodontic irrigants 3% NaOCl, 2% chlorhexidine (CHX), and 17% ethylenediaminetetraacetic acid (EDTA) using spectroscopic analyses.

MATERIALS AND METHODS

In this in vitro study, 3% NaOCl, 2% CHX, and 17% EDTA were mixed with 4% AHa individually. 1.7 ml of 4% AHa from the cartridge was mixed with 1.7 ml of each test irrigants. The solutions were subjected to a preliminary ultraviolet spectroscopic (UVS) analysis to assess forpotential interactions (if any). If the interaction was detected, the test solutions were further subjected to nuclear magnetic resonance (NMR) analysis for characterization. The precipitate formed (if any) was then subjected to NMR analysis.

RESULTS

UVS analysis revealed a bathochromic shift when 3% NaOCl and 2% CHX were mixed with 4% AHa, respectively. This shift was not observed when EDTA was mixed with 4% AHa. 1H and 13C NMR spectra confirmed the interaction between 3% NaOCl with 4% AHa, which resulted in a precipitate formation, methyl 3-amino-4-methylthiophene-2-carboxylate (MAMC). The analysis of 1H NMR spectra showed peaks at 7.1 ppm, 2.21 ppm, and 9.93 ppm, respectively, which corresponds to aromatic ring protons. A peak at 3.8 ppm was assigned to methyl proton of methyl ester. The characteristic appearance of peaks at 14.82 and 51.16 ppm corresponds to aliphatic carbons. The five peaks occurring at 126, 134.5, 139.2, 156.5, and 162.9 ppm correspond to the aromatic carbon atoms present in the thiophene unit. NMR spectra revealed no interaction between 2% CHX and 4% AHa. 1H and 13C NMR spectra confirmed that 3% NaOCl interacted with 4% AHa, leading to the formation of a precipitate MAMC.

CONCLUSION

3% NaOCl interacted with 4% AHa leading to the formation of a precipitate MAMC which is reported to exhibit the least toxicity. Until the precipitate is studied further, it would be advisable to avoid the immediate use of NaOCl following administration of intrapulpal anesthetic solution with articaine hydrochloride (with adrenaline).

Effects of Acetaminophen and Ibuprofen on Pulpal Anaesthesia Immediately after Pulpectomy of Primary Maxillary Molars

Introduction

This study aimed to evaluate the effects of acetaminophen and ibuprofen on pulpal anaesthesia immediately after pulpectomy of primary maxillary molars.

Methods and Materials

In this placebo-controlled, double-blind clinical trial, 60 children (aged 5 to 9) were referred to the Department of Pediatric Dentistry, Yazd Dental School; for primary maxillary molar pulpectomy. Local anaesthesia and analgesic drugs were used for the pre-operative stage. A five-face scale was considered to evaluate pain reaction during the pulp therapy. Pain scores were determined when the dental procedure was complete. The Kruskal-Wallis and Mann-Whitney U tests were finally used at the confidence level of 95%.

Results

Use of analgesics before pulpectomy in children can reduce pain score compared to placebo group (P<0.001) and increase the effectiveness of pulpal anesthesia. Additionally, ibuprofen exhibited lower pain scores compared to acetaminophen although the difference was not statistically significant.

Conclusions

Pre-operative use of ibuprofen and acetaminophen might be a useful way to achieve analgesia during pulpectomy of primary maxillary molars in children.