Needle Gauge Influences Pain Perception During Intrapulpal Anaesthesia - A Randomized Clinical Trial

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.

The bevel effect: a prospective, randomized investigation into needle design in dental intraligamentary anesthesia

OBJECTIVES

This in vivo study aimed to assess the impact of needle bevel design on puncture pain, anesthetic success, and mechanical deformations in intraligamentary injection (ILA) cases, comparing a short triple facet cut (STF) to a triple lancet cut (TL) after single or repetitive use.

MATERIALS AND METHODS

In a prospective single-blind trial, 200 ILA needles (STF, n = 100; TL, n = 100) were randomly assigned for dental procedures. Patients received ILA either with STF or TL needles, used once (group A; n = 50 each) or repeatedly (group B; n = 50). Puncture pain was assessed using a numerical rating scale (NRS). Anesthetic success was determined via cold spray (yes/no), and scanning electron microscopy (SEM) analyzed needle tip deformations.

RESULTS

Puncture pain did not significantly differ between STF and TL, regardless of needle use or injection area. Success rates were comparable in single use (82% STF vs. 79% TL; p > 0.05). For repetitive use, STF exhibited a significantly higher success rate (80% vs. 69%; p = 0.012). Mechanical deformations were prevalent in 97.5% of needles, with TL showing greater deformations than STF after single and repeated uses. Barbs were more common in TL (90/100) than STF (84/100), with a higher relative risk for barbed-like deformation in TL (RR single use: 1.26; p < 0.001; multiple use: 7.87, p < 0.001).

CONCLUSIONS

The short triple facet-designed bevel demonstrated significantly less mechanical deformation, suggesting potential advantages in maintaining needle lumen patency.

CLINICAL RELEVANCE

The intraligamentary needle bevel design is linked to mechanical deformation and anesthetic success after repetitive use, but not to puncture pain.

Microfluidic Delivery of High Viscosity Liquids Using Piezoelectric Micropumps for Subcutaneous Drug Infusion Applications

Goal: Auto-injectors for self-administration of drugs are usually refrigerated. If not warmed up prior to the injection, ejection of the total drug volume is not guaranteed, as their spring and plunger mechanism cannot adjust for a change in viscosity of the drug. Here, we develop piezoelectric micro diaphragm pump that allows these modifications possible while investigating the effectiveness of this alternative dosing method. Methods: The dosing of highly viscous liquid of 25 mPa·s is made possible using application-specific micropump design. By comparing the analytical with experimental results, the practicality of the concept is verified. Results: Using a powerful piezoelectric stack actuator, the micropump achieves high fluid pressures of up to (368 ± 17) kPa. In order to assess the influence of viscosity, we characterize the fluidic performance of the designed micropump through 27G gauge needle for various water-glycerin mixtures. We find maximum flow rates of 2 mL/min for viscosities of up to 25 mPa·s. Conclusions: The developed micro diaphragm pump enables the development of smart auto-injectors with flow rate regulation to achieve drug delivery for high viscosity drugs through 27G needles.

Anesthetic Efficacy of Endo-Ice and Intrapulpal Ice Sticks After Inferior Alveolar Nerve Block in Symptomatic Irreversible Pulpitis: A Randomized Controlled Study

BACKGROUND

There is a dearth of studies to assess the effectiveness of cryotherapy as a possible adjuvant in anesthesia. Therefore, this study aimed to compare the impact of pretreatment intraoral ice packs, application of Endo-ice, and a combination of Endo-ice and intrapulpal ice sticks use on the effectiveness of pulpal anesthesia as an adjunct in the management of pain and dental anxiety in mandibular second molars with symptomatic irreversible pulpitis (SIP) against traditional inferior alveolar nerve block (IANB) technique.

MATERIALS AND METHODS

The randomized controlled double-blind clinical study comprised of 200 subjects within the age group of 20-45 years with SIP involving mandibular second molars and divided into four groups of 50 each. Conventional IANB was administered in group 1. Intraoral compact ice packs, Endo-ice, and combined use of Endo-ice and intrapulpal ice sticks were employed following conventional IANB in groups 2, 3, and 4, respectively. The intensity of pain and anxiety before and after the intervention was documented using Heft-Parker visual analog scale (HP-VAS) and Corah's Dental Anxiety Scale-Revised (DAS-R).

RESULTS

The average age of the overall study sample was 30.8±2.08 years, and the differences in age and gender distribution were found to be statistically insignificant. The mean HP-VAS scores on access opening and pulpectomy, using ANOVA paired with Tukey's post hoc multiple comparison tests were evaluated to be statistically highly significant (p<0.001). The greatest reduction in HP-VAS score was observed in group 4 receiving combined use of both Endo-ice and intrapulpal ice sticks. While the pretreatment DAS-R score was determined to be statistically insignificant between groups, group 1 subjects had the highest DAS-R score postoperatively (p<0.001). The effectiveness of pulpal anesthesia was found to be 84%, 96%, 92%, and 98% for groups 1 through 4, respectively, and demonstrated a statistically significant difference.

CONCLUSION

The combined use of Endo-ice and intrapulpal ice sticks used as an adjuvant to local anesthesia (LA) was found to be significantly effective in lowering pain compared to the control groups in molars with SIP. Cold administration before and during the procedure was more effective than conventional LA in lowering intraoperative anxiety. Furthermore, the use of Endo-ice and intrapulpal cold after IANB significantly improves the effectiveness of pulpal anesthesia in mandibular second molars with SIP.