A new method of topical anesthesia by using anesthetic solution in a patch

Present status and future directions - Mechanisms and management of local anaesthetic failures

Pain control during root canal treatment is of utmost importance for both the patient and the dental practitioner and many studies have investigated ways of overcoming problems with gaining adequate anaesthesia during treatment. The PubMed and Cochrane databases were searched for evidence-based studies regarding local anaesthesia for root canal treatment. Many variables, including premedication, pain during needle insertion, pain on injection, premedication with various types of drugs, volume of anaesthetic solutions, supplemental anaesthetic techniques, and additives to the anaesthetic solutions, may influence pain perception during root canal treatment. Differences between teeth with healthy pulps versus those with irreversible pulpitis should be considered when the effects of variables are interpreted. There are several concerns regarding the methodologies used in studies that have evaluated anaesthesia success rates. There are some conditions that may help to predict a patient's pain during root canal treatment and these conditions could be overcome either by employing methods such as premedication with a non-steroidal anti-inflammatory drug prior to the treatment visit or by using supplementary anaesthetic techniques before or during the treatment. However, authors need to be more careful when reporting details of their studies to reduce concerns regarding their study bias.

Effects of different topical anesthetics on pain from needle insertion and injection, and the influence of anxiety in patients awaiting endodontic treatment

Objectives

This study aimed to evaluate the effects of 5% lidocaine and 2.5% lidocaine/2.5% prilocaine topical anesthetic on pain during needle insertion and infiltration injection in the labial mucosa of anterior maxillary teeth, and to assess the relationship between patients’ anxiety and pain scores.

Materials and Methods

The Modified Dental Anxiety Scale questionnaire was applied and recorded. Patients were randomly divided into 4 groups (n = 30), as follows: G1 group: 5% lidocaine and placebo for 1 minute, G2 group: 2.5% lidocaine/2.5% prilocaine and placebo for 1 minute, G3 group: 5% lidocaine and placebo for 3 minutes, and G4 group: 2.5% lidocaine/2.5% prilocaine and placebo for 3 minutes. Before the application of topical anesthesia, one side was randomly selected as the topical anesthesia and the contralateral side as the placebo. The pain levels were measured with Visual Analog Scale (VAS) immediately after needle insertion and injection and were compared. The correlation between anxiety and pain scores was analyzed.

Results

Administration of 5% lidocaine for 1 minute had significantly higher pain scores for both insertion and infiltration injection than the other groups (p < 0.05). There was a significant moderate positive correlation between dental anxiety and the injection-induced VAS pain score in the placebo side in all groups (p < 0.05).

Conclusions

Topical anesthetics significantly reduced the pain caused by both needle insertion and injection pain in comparison to the placebo side. The pain scores of patients with dental anxiety were lower on the topical anesthesia compared to the placebo side.

Trial Registration

Thai Clinical Trials Registry Identifier: TCTR20201217002

Does the use of topical anesthetics reduce the perception of pain during needle puncture and anesthetic infiltration? Systematic review and meta-analysis of randomized controlled trials

The objective of this systematic review was to assess whether the use of topical anesthetics reduces the perception of pain during puncture and anesthetic infiltration. Twenty-two randomized controlled clinical trials, published in English on or before August 6, 2020, were found in the PubMed/MEDLINE, Scopus, and Cochrane Library databases. Risk of bias was determined for randomization and other issues. A total of 1029 patients were evaluated using parameters such as type of topical anesthetic, application site, and pain (measured on a scale). Some studies assessed more than one topical anesthetic. Seventeen of them showed a reduction in pain from needle puncture and four from infiltration. Meta-analyses for some results showed considerable statistical heterogeneity. Regarding pain during needle puncture of the maxilla, statistically significant differences were observed in the topical anesthetics group, in both the vestibular (P = 0.0002) and palatal (P = 0.005) region. This was different from the mandible, for which there was no statistically significant difference (P = 0.07). With regard to pain caused by anesthetic infiltration in the maxilla, there was no difference in the use of anesthetic in relation to the control group (P = 0.11). Given these findings, using topical anesthetics only relieves pain during needle puncture and in the maxilla. PROSPERO 2020: CRD42020206362.

Effect of epinephrine on the absorption of lidocaine following application to the oral mucosa in rats

Background

We investigated the role of epinephrine in prolonging the localization of lidocaine on the oral mucosa and inhibiting its absorption in the blood of rats.

Methods

We used 7–8-week-old pathogen-free Wistar male rats (n = 128) for our study. We divided them into the control group administered with ¹⁴C-labeled lidocaine hydrochloride gel only and the study group administered with ¹⁴C-labeled lidocaine hydrochloride gel with epinephrine. The medications were administered in the palatal mucosa of the rats. The amount of mucosa, palatine bone, and serum lidocaine was measured by radioactivity using a liquid scintillation counter and was observed using autoradiograms.

Results

Initially, there was no significant difference in the lidocaine levels between the lidocaine and lidocaine with epinephrine groups in the palatal mucosa (751.9 ± 133.8 vs. 669.8 ± 101.6 ng/mg [2 min]). After 4 min, the values were significantly lower in the lidocaine with epinephrine group (1040.0 ± 142.8 vs. 701.2 ± 109.0 ng/mg [20 min]). After 40 min, the lidocaine level became significantly higher in the lidocaine with epinephrine group (586.8 ± 112.4 vs. 1131.3 ± 155.2 ng/mg [40 min]). Similar results were observed in the palatine bone and serum.

Conclusion

Epinephrine prolonged the localization of lidocaine applied to the mucosa and inhibited its absorption into the bloodstream of rats. Clinical studies are required to evaluate the use of epinephrine-containing topical anesthetics on the oral mucosa.

Topical anesthesia for stainless steel crown tooth preparation in primary molars: a pilot study

Background

Placement of full-coverage restorations such as stainless steel crowns (SSCs) for pulpectomy treated primary molars is essential for successful outcomes. The tooth preparation process for SSCs can cause discomfort to gingival tissues since the crown should be seated 1 mm subgingivally. The purpose of this prospective trial was to compare the effectiveness of subgingival and transmucosal application of topical anesthetics on dental pain during SSC tooth preparation among 6- to 8-year-old children.

Methods

A consecutive sample of 27 children, aged 6-8 years, who required an SSC after pulp therapy in primary molars were randomly divided into three groups. Group A received infiltration anesthesia before tooth preparation for SSC placement, whereas in Group B and C, only topical anesthesia was applied subgingivally and transmucosally. Wong-Bakers Faces pain rating scale (WBFPS) scores were recorded after tooth preparation. Faces, Legs, Activity, Cry and Consolability (FLACC) scores were evaluated by two blinded and calibrated investigators through video recordings of the patient during tooth preparation. Data were tabulated, and inter-group comparisons were performed using the Kruskal-Wallis and analysis of variance tests.

Results

Out of the 27 participants, 48% were boys and 52% were girls, with an overall mean age of 6.83 years. Group A showed the least pain scores according to both the scales, followed by Group B and Group C. The pain intensity was statistically significant on both the pain scales with P = 0.003 for FLACC and P < 0.001 for WBFPS.

Conclusion

Subgingival application of topical anesthesia reduced pain to a certain extent but not as effectively as infiltration anesthesia during SSC tooth preparation in primary molars. Transmucosal application of topical anesthesia did not reduce discomfort when compared to the other two interventions.

Effect of Topical Anesthesia Using an Adhesive Patch and Anesthetic Solution

We analyzed trigeminal somatosensory evoked potentials (TSEP) to the alveolar mucosa to investigate the efficacy of an amide local anesthetic, 2% lidocaine hydrochloride with 12.5 μg/mL epinephrine (Lido treatment) as a topical anesthetic. Eighteen consenting healthy adult volunteers were enrolled. A volume of 0.06 mL of Lido, 0.06 g of 20% benzocaine, or 0.06 mL of physiological saline (control) was instilled onto a hemostatic adhesive patch, which was then applied to the alveolar mucosa at the maxillary right canine for 5 minutes. An electrical stimulus approximately 5 times that of the sensory threshold was applied using a surface stimulation electrode. The trigeminal somatosensory evoked potential was recorded immediately, 5 minutes, and 10 minutes after removal of the patch. Positive P125 and P310 peaks and negative N100 and N340 peaks were observed as a result of the electrical stimulation. A significant decrease in the percentage change in amplitude of N100-P125 was observed in the Lido treatment immediately, 5 minutes, and 10 minutes after patch removal. In the Lido treatment, trigeminal somatosensory evoked potential amplitude at N100-P125 decreased significantly, suggesting that topical anesthesia produced by an amide local anesthetic may have a topical anesthetic effect as potent as that produced by an ester local anesthetic.

Transformation of the peripheral intravenous catheter placement experience in pediatrics

BACKGROUND

"Needle pokes" are the most frequent cause of pain encountered by pediatric patients in the hospital setting. Poor control of pain during needle pokes leads to short- and long-term adverse outcomes for both patients and hospitals. J-Tips are a needle-free injection system that use pressurized gas to inject lidocaine in a fine stream of fluid that penetrates the skin. This study undertook an evaluation of their effectiveness at decreasing the pain of the needle poke that takes place with IV insertion.

METHODS

Participation was limited to patients between the ages of 3 and 16 who received an IV during a 3-week period at an academic pediatric hospital. Furthermore, patients requiring more than one attempt to place the IV were not included. Participants were recruited within 24 hours after having received their IV. The 10-point, Wong-Baker Faces Pain Rating Scale was the tool used to collect pain scores. Patients were recruited to the study by convenience sampling.

RESULTS

Pain scores were collected from 85 patients. There were 41 patients who received needle-free injected lidocaine prior to IV insertion. There were 44 patients who received an IV without previous lidocaine injection. Mean pain scores for the two groups were 2.45 for the patients who received the needle-free injected lidocaine and 5.8 for the patients who did not (p value <0.001).

CONCLUSIONS

Results were consistent with the hypothesis that needle-free injection of lidocaine is an effective therapy for the management of pain in children between the ages of 3-16 years who receive an IV.