Comparison of topical anesthetics (EMLA/Oraqix vs. benzocaine) on pain experienced during palatal needle injection

Efficacy of topical anesthetics of lidocaine, benzocaine, and EMLA in reducing pain during inferior alveolar nerve block in schoolchildren: a randomized controlled trial

OBJECTIVES

This study aimed to evaluate the efficacy of 5% EMLA cream and 8% lidocaine gel in reducing pain during inferior alveolar nerve block (IANB) compared with 20% Benzocaine in children aged 6-10 years.

MATERIALS AND METHODS

This was a triple-blinded, randomized, parallel-group, active-controlled trial with three arms. 45 children were randomly assigned into 3 groups. Group 1: control group, 20% benzocaine gel (n = 15). Group 2: 8% lidocaine gel (n = 15). Group 3: 5% EMLA cream (n = 15). Each topical anesthetic was applied in an amount of 0.3 mL using a cotton swab for 2 min, followed by IANB administration. The following primary outcome measures were considered: pulse rate, the face, legs, activity, cry, consolability (FLACC) behavioral pain assessment scale, and the Wong-Baker FACES pain rating scale.

RESULTS

The mean score of the FLACC behavioral pain assessment scale in group 2 (2.20 ± 1.86) was slightly higher, but this result was not statistically significant p = (0.806). Regarding the Wong-Baker FACES pain rating scale scores, no statistically significant difference was noted between the study groups p = (0.593). After IANB administration, the mean pulse rate was higher in group 3 (102.40 ± 14.28). However, this difference was not statistically significant p = (0.351). In addition, the mean change of the pulse rate from the baseline to this time point was not statistically significant p = (0.638), indicating a smaller physiologic response to the painful stimulus.

CONCLUSION

8% lidocaine gel was not superior to 20% benzocaine nor 5% EMLA in reducing pain during IANB administration.

Assessing α-Bisabolol as a Transmucosal Permeation Enhancer of Buccal Local Anesthetics

Needle-free buccal anesthesia improves dental treatment outcomes for both patients and dentists. In this study, we report on an assessment of the enhancement effects of α-bisabolol on the in vitro transmucosal permeation of prilocaine hydrochloride (PCl) and lidocaine hydrochloride (LCl) from needleless buccal films. We also evaluated the mechanical properties of the film, which consisted of Methocel™ K100 LV as the film-forming polymer (3% m·m-1), PEG 400 as a cosolvent (15% m·m-1 based on drug loading), α-bisabolol (15 and 30% m·m-1 based on drug loading), and the drugs combined at a 1:1 ratio (15 mg·unit-1). The porcine esophageal epithelium was used as a membrane barrier, and artificial saliva was the release medium. After a 1 h experiment at 25 ± 2 °C, α-bisabolol significantly decreased, rather than enhanced, the permeation fluxes (five-fold), permeability coefficients (seven-fold), and retentions (two-fold) of both PCl and LCl through the epithelium, regardless of the concentration. Moreover, the resistance and flexibility of the films markedly decreased compared to those without α-bisabolol. Therefore, under the experimental conditions, using α-bisabolol as a buccal permeation enhancer for the hydrophilic local anesthetics PCl and LCl from buccal films is not feasible.

Acceptability of compounded preparations - A Romanian pediatric hospital perspective

Compounded medicines are widely used, especially for pediatric patients. The aim of this study was to evaluate children's acceptability of compounded preparations and to provide information regarding compounding practices' characteristics in a Romanian hospital setting. An observational, cross-sectional, and retrospective study was conducted in three Clinical Pediatric Departments (Emergency Clinical Hospital for Children, Cluj-Napoca). The study population comprised patients under 18 years old taking at least one compounded medication. Study data was collected mainly through an interviewer-administered questionnaire and medicine acceptability was assessed based on the children's first reaction to the preparations using a 3-point facial hedonic scale. A total of 162 compounded medications were evaluated. A positive/negative reaction was reported for 20.83%/58.33%, 20.63%/49.21%, and 66.67%/7.41% of oral, oromucosal and cutaneous dosage forms. Although patient disapproval was recorded for various reasons, medication administration was successful in over 75% of cases. Factors such as fewer steps required for intake of a dose, capsule dosage form, no additional food/drink immediately after drug intake, medication perceived as "easy/very easy" to swallow, were correlated with a better acceptability of oral preparations. This study highlights the importance of identifying factors that can improve the acceptability of compounded preparations and, subsequently, treatment outcomes in pediatric patients.

Evaluation of EMLA cream with microneedle patches in palatal anesthesia in children: a randomized controlled clinical trial

Palatal injections are considered to be one of the most painful dental procedures. As a result, it was important to find alternatives to this painful injection to improve children's cooperation. The dental literature mentioned using EMLA cream as a possible alternative to conventional injections, but its anesthetic effect was debated. Therefore, it was valuable to research the impact of microneedle patches to enhance the effectiveness of this cream. The purpose of this randomized controlled clinical trial was to compare the effectiveness of different methods of anesthesia and pain levels in children aged 7-11 years. The study compared the use of EMLA cream, EMLA with microneedles, and conventional palatal injections. A total of 90 children were randomly assigned to three groups: Group 1 received conventional palatal anesthesia (control), Group 2 received EMLA cream only, and Group 3 received EMLA with microneedles. Pain levels were assessed using the FLACC and Wong-Baker scales at three different time points: T1(during anesthesia), T2(on palatal probing), and T3(during extraction). The FLACC scale revealed a significant difference in pain between groups only at T1 (P value = 0.000). It was found that the conventional palatal injection group had a higher pain level than the EMLA cream-only group and the group using microneedle patches with EMLA cream (P value = 0.000). However, the other groups did not show significant differences in pain levels during the anesthesia (P value  = 1.00). Similarly, the Wong-Baker scale also demonstrated a statistically significant difference in pain between groups only at T1 (P value  = 0.000). It was found that the conventional palatal injection group had a higher pain level than the EMLA cream-only group and the group using microneedle patches with EMLA cream (P value  = 0.000). However, the other groups did not show significant differences in pain levels during the anesthesia (P value  = 0.091). The study concludes that both EMLA cream alone and EMLA with microneedles can be used as an alternative to conventional palatal anesthesia for children.

Comparative Evaluation of New Needleless Local Anesthetic System (INJEX) and Conventional Syringe Needle Technique during Pulpotomy Treatment: A Randomized Clinical Trial

BACKGROUND

The dreaded sensation of pain in the dental chair has a significant impact on children's behavior. This study aimed to compare and contrast the perception of pain and patient behavior between the use of INJEX and the conventional syringe needle technique during pulpotomy among children.

METHODS

A randomized clinical trial was designed and conducted among pediatric dentistry patients aged 6-12 years old. Fifty-eight children were divided into two groups, conventional syringe needle and INJEX, using simple randomization method applying the sequentially numbered, opaque, sealed envelope method of allocation concealment. Anesthesia was administered to the groups as local infiltration by a single operator following routine behavior guidance techniques. After 3 min, pulpotomy was performed using the standard protocol. The Face, Legs, Activity, Cry, Consolability (FLACC) scale and Wong-Baker FACES Pain Rating Scale (WBS) were used to assess the intensity of pain, while the Frankl behavior rating scale (FBRS) was used to assess the children's behavior.

RESULTS

During anesthesia, most of the participants in the INJEX group (median = 3) had higher FBRS scores compared with the conventional syringe needle group (median = 2), and the difference was very highly significant (p-value < 0.001). Analyzing the FLACC scores during local anesthesia administration revealed a high statistical significance (p-value < 0.01) across the two groups. A very high statistically significant difference (p-values < 0.001) with higher WBS scores for pain intensity was seen in the group using conventional syringe needles.

CONCLUSIONS

INJEX administration significantly reduced the intensity of pain experienced by the children and helped maintain a positive attitude among them during pulpotomy. It provided a positive and comfortable experience for both the child and the practitioner. Therefore, it can serve as an excellent alternative to conventional needle anesthesia.

Novel Microemulsion Containing Benzocaine and Fusidic Acid Simultaneously: Formulation, Characterization, and In Vitro Evaluation for Wound Healing

Modern drug carrier technologies, such as microemulsions with small droplet sizes and high surface areas, improve the ability of low water solubility active ingredients to permeate and localize. The goal of this study was to create microemulsion formulations for wound healing that contained both fusidic acid (FA), an antibacterial agent, and benzocaine (BNZ), a local anesthetic. Studies on characterization were carried out, including viscosity, droplet size, and zeta potential. The drug-loaded microemulsion had a stable structure with -3.014 ± 1.265 mV of zeta potential and 19.388 ± 0.480 nm of droplet size. In both in vitro release and ex vivo permeability studies, the microemulsion was compared with Fucidin cream and oily BNZ solution. According to the drug release studies, BNZ release from the microemulsion and the BNZ solution showed a similar profile (p > 0.05), while FA release from the microemulsion had a higher drug release compared to Fucidin cream (p < 0.001). The microemulsion presented lower drug permeation (p > 0.05) for both active ingredients, on the other hand, provided higher drug accumulation compared to the control preparations. Moreover, according to the results of in vitro wound healing activity, the microemulsion indicated a dose-dependent wound healing potential with the highest wound healing activity at the highest concentrations. To the best of our knowledge, this developed BNZ- and FA-loaded microemulsion would be a promising candidate to create new opportunities for wound healing thanks to present the active ingredients, which have low water solubility, in a single formulation and achieved higher accumulation than control preparations.

Comparative Assessment of Pain during Infiltration by a Two-stage Infiltration Technique: A Double-blind Clinical Trial

AIM

The aim of this study was to assess and compare the pain during infiltration by a modified two-stage local anesthetic infiltration technique under topical anesthesia (TA).

MATERIALS AND METHODS

In this cross-over double-blind study, 30 volunteers participated, where two groups were given single-stage infiltration and the other two had two-stage infiltrations. Depending upon the infiltration technique (one- or two-stage) and the use of TA, the patients were randomly divided into four groups. Local anesthesia (LA) was administered by infiltration into the mucobuccal fold of the maxillary central incisor, and the pain perceived during the infiltration in each group was recorded. The volunteers were recalled after 24 hours to assess the tenderness at the injection site. The volunteers were recalled 2 weeks after infiltration for the subsequent groups to assess the pain for this cross-over study.

RESULTS

A statistically significant difference was observed in the pain perceived when TA was used and when the infiltration was done in two stages. Regarding the pain at the site of injection after 24 hours, no significant difference was observed among the volunteers.

CONCLUSION

Topical anesthesia was effective in reducing the pain of injection when compared to placebo. The pain of injection is further reduced with a two-stage infiltration technique after TA application.

CLINICAL SIGNIFICANCE

Topical anesthesia can be used routinely before infiltration, and LA infiltration injections are less painful if administered in two stages.

The Clinical Efficacy of EMLA as a Topical Anesthetic Agent Instead of Palatal Injection During Maxillary Dental Extractions: A Randomized Controlled Trial

Background

Even after the invention of the modern injection techniques, palatal injection still remains a painful experience for patients, and this pain is attributed to the presence of rich nerve complement and displacement of tightly adherent palatal mucosa during anesthesia.

Aim

To check the clinical efficacy of EMLA as a topical anesthetic agent instead of palatal injection during maxillary dental extractions.

Methodology

The trial includes a total of 102 participants, in whom maxillary molar extractions were indicated, were randomly divided into the experimental group (eutectic mixture of local anesthesia (EMLA) topical application was used along with buccal injection) and control group (palatal injection along with buccal injection). Pain perception during extraction was recorded using the visual analog scale (VAS).

Results

Mean VAS score for 'injection' in control group patients was 5.2 ± 2.08 in contrast to no pain in experimental group. In experimental group, mean VAS score on 'probing' was 0.92 ± 1.50. VAS score on 'extraction' in EMLA group was little higher though the difference was not statistically significant. The overall experience using Liekert's scale was higher in experimental group (4.0 ± 0.76) as compared to (3.3 ± 0.82) in control group leading to higher overall satisfaction among patients who underwent extraction in the experimental group.

Conclusion

EMLA application produced a satisfactory level of anesthesia in the palatal tissue when compared with the palatal injection.

Effect of a needle-free system versus traditional anesthesia on pain perception during palatal injections in children

BACKGROUND

Needle-free injection systems can contribute to the prevention of needle-related pain during palatal infiltration anesthesia (PIA) in children. Research on this topic in children is required.

AIM

The purpose of this clinical study was to evaluate the effectiveness and patient preference of a needle-free system versus traditional anesthesia (TA) on pain perception during PIA in children.

DESIGN

The study was designed as a randomized, controlled crossover clinical study with 48 children aged 6-12 years requiring dental treatment with PIA in bilateral maxillary primary molars. TA was applied on one side and the Comfort-in™ injection system (CIS) on the other side in two separate sessions. Then, patient preference was recorded. The pain perception during PIA was evaluated using the Wong-Baker FACES Pain Rating Scale (PRS) and the Face, Legs, Activity, Cry, Consolability (FLACC) Scale. The data were analyzed for statistical significance (p < .05).

RESULTS

There were statistically significant differences between the TA and the CIS according to the PRS and FLACC Scale scores. On both scales, significantly higher pain ratings were observed in the TA group during PIA (p < .001). There was a statistically significant difference in terms of patient preference (p < .001). Although 77.1% (n = 37) of the children preferred the CIS, 22.9% (n = 11) preferred the TA. Moreover, patient preference for the CIS was significantly higher in older children (p < .01).

CONCLUSIONS

The application of a needle-free system during PIA ensured a decrease in pain perception in children.

Prospective Study on PDL Anesthesia as an Aide to Decrease Palatal Infiltration Pain

OBJECTIVE

The purpose of this prospective randomized study was to assess using a periodontal ligament (PDL) injection as an aide to decrease palatal infiltration pain.

METHODS

A total of 133 subjects randomly received a PDL injection and alternative palatal infiltration or a mock PDL injection and conventional palatal infiltration at 2 separate appointments. PDL injection was given in the mid-palatal sulcus of the maxillary first molar. Mock PDL injection consisted of only needle insertion. All subjects then received a palatal infiltration administered into the blanched gingival tissue 3 mm (alternative palatal infiltration) or 7 mm (conventional palatal infiltration) from the gingival collar. Subjects recorded needle insertion and solution deposition pain using a Heft-Parker visual analog scale (VAS).

RESULTS

The combined PDL injection and alternative palatal infiltration had significantly decreased mean VAS ratings for needle insertion and solution deposition pain (P < .0001). Incidence of moderate/severe pain for needle insertion and solution deposition was reduced from 65% to 1% and from 65% to 2%, respectively.

CONCLUSION

Providing PDL anesthesia into the mid-palatal sulcus of the maxillary first molar and then administering an alternative palatal infiltration into the blanched collar around the PDL molar site led to significant reductions in needle insertion and solution deposition pain compared with a mock PDL and conventional palatal infiltration.

A Comparison in Patient Comfort Using Conventional Syringe and Needleless Jet Anesthesia Technique in Periodontal Surgery—A Split-Mouth Randomized Clinical Trial

Background and Objectives: Periodontal surgery requires local anesthetic coverage to alleviate patient discomfort. Needles and injections can engender feelings of fear and anxiety in individuals. This study aimed to assess the level of comfort and anxiety in patients during the administration of local anesthesia using needleless jet anesthesia (JA) when compared to a conventional syringe (CS) in periodontal surgery. Method and Materials: 60 sites were designated for injection in a split-mouth design in 30 subjects who required periodontal surgery. Local anesthesia was administered in two appointments scheduled one week apart using either a JA system or a CS. The Visual Analogue Scale (VAS), Verbal Rating Scale (VRS), and Beck’s anxiety inventory were used to report the pain and anxiety levels while injecting local anesthesia. Statistical analysis of the results was performed using the Shapiro–Wilks test and Paired t-test. Results: Patients reported greater comfort with JA. The VAS and VRS values were statistically significant—(p = 0.003) and (p = 0.001), respectively. Patients showed fear and were nervous about receiving a local anesthetic using a CS. A few subjects experienced lingering pain with the CS, whereas greater comfort and no lingering soreness were reported post-operatively at the site of JA administration. Conclusion: This study provides the first comprehensive assessment of using JA for periodontal surgical procedures. Lower pain scores were consistently observed with the use of jet injectors. Patients were at ease and reported lesser anxiety and greater comfort with jet injectors, making it ideally suited for providing local anesthesia in periodontal surgery.

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.

Transpapillary Injection Technique as a Substitute for Palatal Infiltration: A Split-mouth Randomized Clinical Trial

Aim and objective

To assess and compare the degree of pain during local anesthesia administration and to evaluate the efficacy of transpapillary injection as a substitute for palatal injection in simple maxillary tooth extractions.

Materials and methods

A split-mouth study was conducted among children aged 7-11 years who required bilateral extraction of maxillary molars. The individuals were subjected to conventional buccal and palatal infiltration for the first extraction. The transpapillary injection was administered for the subsequent extraction in place of palatal administration. 2% lignocaine with 1:100,000 adrenaline was used for both techniques. Faces pain score scale and visual analog scale were utilized to record pain during injection administration and during the extraction process. A p < 0.05 was considered to be statistically significant.

Results

The difference in pain scores was observed during injection administration and was found to be statistically significant (p < 0.05) whereas pain scores for extraction were insignificant (p > 0.05).

Conclusion

The transpapillary injection technique was efficacious in eliminating the pain of the palatal injection technique for maxillary extractions.

Clinical significance

Owing to the results of this study, the transpapillary injection technique can be used as a distinguished substitute for conventional palatal infiltration, thereby lessening the level of distress experienced by a pediatric patient during local anesthesia administration.

How to cite this article

Sruthi MA, Ramakrishnan M. Transpapillary Injection Technique as a Substitute for Palatal Infiltration: A Split-mouth Randomized Clinical Trial. Int J Clin Pediatr Dent 2021;14(5):640-643.

2.5% EMLA Versus 2% Lignocaine with Adrenaline Injection in Small Oral Mucosal Biopsies: A Parallel Group Randomized Controlled Trial

Trial Design

The study was designed as an open label randomized comparative parallel group design with a 1:1 allocation ratio.

Methods

All consecutive patients reporting for small biopsies (incisional or excisional) who gave written informed consent were included in the study between October 2018 and October 2019. They were randomized into two groups, Group A and Group B both receiving intervention in the form of 2.5% EMLA cream and 2% Lignocaine with 1:80,000 Adrenaline injection respectively, to anaesthetise tissue for small mucosal biopsies in the oral cavity.

Results

EMLA was found to be as effective as lignocaine infiltration with a completely painless application and higher satisfaction for overall comfort during procedure. The duration required to achieve anaesthesia was however more. A particular subgroup of pathology was found to be completely resistant to anaesthesia by EMLA.

Conclusion

We recommend the use of EMLA as a sole anaesthetic in small mucosal biopsies and shavings in all patients. We suggest it as a higher and first line recommendation for anaesthesia in needle phobic patients and children.

Effects of Dexmedetomidine as an Analgesic Adjuvant for Surgery of Femur Fracture: A Systematic Review and Meta-Analysis

Patients who undergo surgery of femur fracture suffer the excruciating pain. Dexmedetomidine (DEX) is a unique α2-adrenergic receptor agonist with sedative and analgesic properties, whose efficacy and safety are still unclear for surgery of femur fracture. Randomized controlled trials comparing the effects of addition of DEX to general or local anesthesia in surgery of femur fracture were searched from MEDLINE, EMBASE, and the Cochrane Library database. Patients who received DEX infusion had a significant longer time to rescue analgesia compared with those without DEX coadministration. DEX treatment seemed to reduce the visual analog score; however, the significance did not reach any statistical difference. DEX as an analgesic adjuvant did not reduce the onset of sensory block time, shorten the time to achieve maximum sensory block level, and provide a longer duration of sensory block. The difference in mean sedation scores between 2 groups was not statistically significant. As for adverse effects, DEX therapy significantly increased the rate of hypotension. In conclusion, dexmedetomidine as a local anesthetic adjuvant in femur fracture surgery had a longer duration of rescue analgesia. However, the incidence of hypotension was markedly increased in these patients. It was worth noting that the evidence was of low to moderate quality.

Towards the advance of a novel iontophoretic patch for needle-free buccal anesthesia

The aim of this work was to develop a mucoadhesive iontophoretic patch for anesthetic delivery in the buccal epithelium. The patch was comprised of three different layers, namely i) drug release (0.64 cm²); ii) mucoadhesive (1.13 cm²); and iii) backing (1.13 cm²). Prilocaine and lidocaine hydrochlorides were used as model drugs (1:1 ratio, 12.5 mg per unit). An anode electrode (0.5 cm² spiral silver wire) was placed in between the drug release and mucoadhesive/backing layers to enable iontophoresis. Surface microscopy; mechanical and in vitro mucoadhesive properties; drug release kinetics and mechanism; and drug permeation through the porcine esophageal epithelium were assessed. Topographic analysis evidenced differences in the physical structures for the several layers. All layers presented suitable handling properties i.e., flexibility, elasticity and resistance. Both the release and mucoadhesive layers presented features of a soft and tough material, while the backing layer matched the characteristics of a hard and brittle material. A synergy between the drug release and mucoadhesive layers on the mucoadhesive force and work of adhesion of the tri-layered patch was observed. Passive drug release of both drugs fitted to First-order, Hixson-Crowell and Weibull kinetic models; and the release mechanism was attributed to anomalous transport. Iontophoresis remarkably enhanced the permeation of both drugs, but mainly prilocaine through the mucosa as evidenced by the permeability coefficient parameter (3.0-fold). The amount of these amino amide salts retained in the mucosa were also equally enhanced (4.7-fold), while the application of a tiny constant electric current (1 mA·cm^-2·h^-1) significantly decreased the lag time for lidocaine permeation by about 45%. In view of possible in vitro / in vivo correlations, the buccal iontophoretic patch displays a promising strategy for needle-free and patient-friendly local anesthesia in dentistry.

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.

The effectiveness of electronic pulsed soft tissue vibration compared with topical anaesthesia in reducing the pain of injection of local anaesthetics in adults: a randomized controlled split-mouth clinical trial

The purpose of this study was to evaluate the effectiveness of an electronic hand-held pulsed vibration device on the pain of local analgesia (LA) injection and physiologic changes. A prospective randomized controlled clinical trial using split-mouth (crossover) design was implemented. The control-side injection was performed after using topical anaesthesia. The experimental side injection was carried out without topical anaesthesia, but with the aid of a switched-on vibration device. Overall, 332 dental LA injections were given to 166 patients for routine exodontia. The pain at penetration and pain during injection were significantly lower in the experimental sides (vibrations sides) compared with those of the controls (P<0.001). Similarly, the heart rate changes at penetration and during injections were significantly lower in the experimental sides (P<0.001). The vibration device was clinically and statistically more effective than topical anaesthesia in the reduction of dental injection pain in adults, measured subjectively and objectively, regardless of the gender, injection technique (infiltration or block) or anxiety level.

Pain perception and efficacy of local analgesia using 2% lignocaine, buffered lignocaine, and 4% articaine in pediatric dental procedures

Background

The purpose of this study was to compare the pain perception and anesthetic efficacy of 2% lignocaine with 1:200,000 epinephrine, buffered lignocaine, and 4% articaine with 1:200,000 epinephrine for the inferior alveolar nerve block.

Methods

This was a double-blind crossover study involving 48 children aged 5–10 years, who received three inferior alveolar nerve block injections in three appointments scheduled one week apart from the next. Pain on injection was assessed using the Wong-Baker Faces pain scale and the sound eye motor scale (SEM). Efficacy of anesthesia was assessed by subjective (tingling or numbness of the lip, tongue, and corner of mouth) and objective signs (pain on probing).

Results

Pain perception on injection assessed with Wong-Baker scale was significantly different between buffered lignocaine and lignocaine (P < 0.001) and between buffered lignocaine and articaine (P = 0.041). The onset of anesthesia was lowest for buffered lignocaine, with a statistically significant difference between buffered lignocaine and lignocaine (P < 0.001). Moreover, the efficacy of local analgesia assessed using objective signs was significantly different between buffered lignocaine and lignocaine (P < 0.001) and between lignocaine and articaine.

Conclusion

Buffered lignocaine was the least painful and the most efficacious anesthetic agent during the inferior alveolar nerve block injection in 5–10-year-old patients.

Assessment of anesthetic properties and pain during needleless jet injection anesthesia: a randomized clinical trial

Pain due to administration of local anesthetics is the primary reason for patients' fear and anxiety, and various methods are used to minimize it. This study aimed to measure the degree of pain during administration of anesthesia and determine the latency time and duration of pulpal anesthesia using two anesthetic methods in the maxilla.

Full-Thickness Intraoral Mucosa Barrier Models for In Vitro Drug-Permeation Studies Using Microneedles

The use of permeation enhancers such as microneedles (MNs) to increase drug penetration across intraoral mucosa has increased in recent years. Permeation studies, commonly performed using vertical diffusion cells, are a well-established way to preview formulations and enhance their performance during the development stage. However, to our knowledge, the existing intraoral mucosa barrier models do not permit permeation using MN-pretreated mucosa due to their insufficient thickness. Therefore, the objective of this study was to develop a barrier model using thick palate tissues to perform in vitro permeation studies, with physical enhancement of the permeability of intraoral mucosa by pretreatment with MNs. The adapted Franz-type cells used in the permeation experiments were validated (cell dimensions and volume, sealing effectiveness, stirring and dissolution efficiency, temperature control, and establishment of uniaxial flux). Commercially available MNs were used in the palatal mucosa. Optical images of the mucosa were acquired to analyze the microperforations created. In vitro permeation studies were conducted with the MN-pretreated mucosa. This work presents a new in vitro method for the evaluation of MNs as permeation enhancers, with the aim of improving the absorption of drug formulations topically applied within the oral cavity.

Influence of needle bevel design on injection pain and needle deformation in dental local infiltration anaesthesia - randomized clinical trial

The aims of this in vivo study were to evaluate the impact of needle bevel design on patients' pain perception and the mechanical deformation of the needle tip after the injection. In a prospective single-blinded trial, 150 patients received conventional infiltration anaesthesia for dental treatment by one examiner. Patients were randomized for one out of three different needle bevel types (scalpel-designed bevel needle (SB), n=50; triple bevel needle (TB), n=50; regular bevel needle (RB), n=50). Subjects' self-reported injection pain perception was evaluated using a numeric rating scale (NRS). For each needle tip, deformations after single use were measured using SEM. A significant lower injection pain level was found in SB (mean 2.1±1.2) than in TB (mean 3.5±1.6;) and RB (mean 3.4±1.0; all P<0.001). A needle deformation was detected in about 97.3% of all needles (SB 50/50, TB 50/50, and RB: 46/50). A higher number of barbs were found in SB (29/50) versus TB (17/50) and RB (19/50). For dental local infiltration anaesthesia, injection needles with a scalpel-designed bevel demonstrated significantly less injection pain. Needle tip deflections after anaesthetic agent infiltration, especially barbed hooks on the non-cutting edge may result in greater soft tissue trauma.

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.

The effect of a lidocaine/prilocaine topical anesthetic on pain and discomfort associated with orthodontic elastomeric separator placement

Background

The initial placement of orthodontic elastomeric separators can be uncomfortable and painful. Therefore, it is important to relieve this disturbing sensation to create a discomfort or pain-free orthodontic visit. The purpose of this study was to investigate the effect of a lidocaine/prilocaine topical anesthetic on pain and discomfort associated with the placement of orthodontic elastomeric separators.

Methods

Fifty subjects aging between 20–35 years were included in this study. In the maxillary arch, a lidocaine/prilocaine topical anesthetic was placed around the ginigval margins of the premolar and molar on side. On the other side, a placebo agent was placed around the ginigval margins of the premolar and molar. After two minutes, an elastomeric separator was placed between the premolar and molar on both sides. The subjects were then asked to report their findings on a Verbal Scale and a Visual Analogue Scale every second minute for a period of 10 min. The subjects were also given a questionnaire to evaluate the overall impression on the topical anesthetic use.

Results

The overall mean discomfort/pain score was found to be significantly lower (p < 0.001) with the topical anesthetic than with the placebo. Repeated measures ANOVA with a Greenhouse-Geisser correction determined that mean pain scores were statistically significantly low with the 10-min time duration (F_(1.54,42.2) = 40.7, p = 0.001), with an estimated grand mean (8.37, 95% CI 6.75–9.98). The questionnaire responses revealed that 87% of the subjects reported an overall satisfaction and agreement with the topical anesthetic than with the placebo or no difference (13%) after the initial separator placement.

Conclusions

The discomfort and pain resulting from the initial placement of orthodontic elastomeric separators can be significantly reduced with the lidocaine/prilocaine topical anesthetic.

Recent advances in topical anesthesia

Topical anesthetics act on the peripheral nerves and reduce the sensation of pain at the site of application. In dentistry, they are used to control local pain caused by needling, placement of orthodontic bands, the vomiting reflex, oral mucositis, and rubber-dam clamp placement. Traditional topical anesthetics contain lidocaine or benzocaine as active ingredients and are used in the form of solutions, creams, gels, and sprays. Eutectic mixtures of local anesthesia cream, a mixture of various topical anesthetics, has been reported to be more potent than other anesthetics. Recently, new products with modified ingredients and application methods have been introduced into the market. These products may be used for mild pain during periodontal treatment, such as scaling. Dentists should be aware that topical anesthetics, although rare, might induce allergic reactions or side effects as a result of an overdose. Topical anesthetics are useful aids during dental treatment, as they reduce dental phobia, especially in children, by mitigating discomfort and pain.

The efficacy of eutectic mixture of local anesthetics as a topical anesthetic agent used for dental procedures: A brief review

Dental pain management is one of the most critical aspects of modern dentistry which might affect patient's quality of life. Several methods are suggested to provide a painless situation for patients. Desensitization of the oral site using topical anesthetics is one of those methods. The improvements of topical anesthetic agents are probably one of the most important advances in dental science in the past 100 years. Most of them are safe and can be applied on oral mucosa with minimal irritation and allergic reactions. At present, these agents are various with different potent and indications. Eutectic mixture of local anesthetics (EMLA) (lidocaine + prilocaine) is a commercial anesthetic agent which has got acceptance among dental clinicians. This article provides a brief review about the efficacy of EMLA as a topical anesthetic agent when used during dental procedures.

Low intensity laser for reducing pain from anesthetic palatal injection

OBJECTIVE

The aim of this study was to evaluate the effectiveness of pain reduction techniques for palatal injection, namely, low intensity laser therapy (LILT), topical anesthesia, pressure, and light touch.

BACKGROUND DATA

Previous evidence indicates that LILT may prevent pain from palatal injection. However, no clinical trials evaluating this clinical question have been performed.

METHODS

A double-blind clinical trial was conducted using 80 healthy volunteers, 18-25 years of age. The subjects were randomly allocated into four groups with 10 females and 10 males each group. Pain reduction techniques were administered at an injection point that was 10 mm from the margin of the palatal gingiva of the upper left first molar according to the following groups: (1) a 790 nm 30 mW continuous wave with a 0.13 cm2 focal spot at an applied energy of 3.6 J and fluence of 27.69 J/cm2, (2) 20% benzocaine, (3) pressure, and (4) light touch as the control. Then, 2% lidocaine with 1:100,000 epinephrine was injected using a 27-gauge needle with a pressure and volume control intraligamentary syringe. All subjects recorded pain on a 10 cm visual analog scale (VAS).

RESULTS

The pain score in the LILT group was <50 mm. The median of pain scores of the LILT, 20% benzocaine, pressure, and light touch groups were 11, 23, 27, and 31 mm, respectively. There was no statistically significant difference in VAS among the groups, using Kruskal-Wallis test (p=0.385).

CONCLUSIONS

No statistically significant differences in pain scores were noted among low intensity laser, 20% benzocaine, pressure, and light touch.

Development and Evaluation of a Novel Mucoadhesive Film Containing Acmella oleracea Extract for Oral Mucosa Topical Anesthesia

Purpose

To develop an anesthetic mucoadhesive film containing Acmella oleracea (jambu) extract for topical use on oral mucosa.

Methods

Ethanolic extracts from aerial parts of jambu were prepared by maceration. Pigment removal was obtained by adsorption with activated carbon. Three mucoadhesive films were developed using a film casting method: 10 or 20% of crude jambu extract (10% JB and 20% JB), and 10% of crude jambu extract treated with activated carbon (10% JBC). The mucoadhesive films were characterized regarding their uniformity, thickness, pH, and spilanthol content, and their stability was evaluated during 120 days. Gas chromatography was used to quantify the amount of spilanthol. In vitro tests determined the permeation of spilanthol across pig esophageal epithelium mucosa in Franz diffusion cells. Topical anesthetic efficacy was assessed in vivo using a tail flick test in mice.

Results

The three mucoadhesive films showed physical stability and visual appearances suitable for use on oral mucosa. The permeation study revealed that the spilanthol from 10% JBC presented higher flux and permeability coefficient values, compared to 10% or 20% JB (p < 0.001). Moreover, 10% JBC showed better topical anesthetic efficacy than the other films (p < 0.01).

Conclusion

Mucoadhesive film containing crude extract of jambu treated with activated carbon is a potential alternative for oral, topical use, encouraging future clinical studies.

Intra-pocket anaesthesia and pain during probing, scaling and root planing: a systematic review and meta-analysis

AIM

A systematic review/meta-analysis was performed to evaluate pain during probing, scaling and root planing using intra-pocket anaesthesia versus placebo in adult patients.

METHODS

A search was performed in PubMed, Scopus, Web of Science, Latin American and Caribbean Health Sciences Literature database, Brazilian Library in Dentistry, Cochrane Library and Grey literature. IADR abstracts, unpublished trials registries, dissertations and theses were also searched for randomized clinical trials comparing the clinical effectiveness of intra-pocket anaesthesia and placebo. Risk/intensity of pain was the primary outcome. The risk of bias tool from the Cochrane Collaboration was used for quality assessment. Meta-analysis was performed on studies considered at low risk of bias.

RESULTS

A total of 1740 articles were identified. Eleven remained in the qualitative synthesis, and nine studies were considered at "low" risk of bias for meta-analysis. Standardized Hedge's g mean difference for pain intensity using visual analogue scale and Heft-Parker pain scales was -0.576 (95% confidence interval [CI] -0.94 to -0.22; p = 0.002) and for verbal rating scale pain scale it was -1.814 (95% CI -3.38 to -0.245; p = 0.023). The odds ratio for the risk of pain was 0.025 (95% CI 0.003 to 0.25; p = 0.002) and the odds ratio for the need for rescue anaesthesia it was 0.358 (95% CI 0.174 to 0.736; p = 0.005).

CONCLUSIONS

The anaesthetic gel decreases the risk and intensity of pain during probing/SRP.

Blood concentration of prilocaine and lidocaine after the use of topical anesthesia (Oraqix® ) in lacerated wounds

BACKGROUND/AIM

Soft tissue injuries have been reported as being sutured using only topical anesthesia applied in the laceration wound. The objective of this study was to assess the pharmacokinetic profile of components of Oraqix^® (2.5% prilocaine and 2.5% lidocaine) when applied in a laceration as compared to intact skin application in the mouse.

MATERIALS AND METHODS

A total of 200 BALB/c male mice were used in this study. The mice were divided into three groups: group A: shaved and laceration group (80 mice); B: shaved and intact skin group (80 mice); and C: control group (shaved, no treatment; 40 mice) which underwent the same procedures but without application of Oraqix^® . Blood samples were collected over 90 min. Plasma sample analysis employing liquid chromatography coupled with the tandem mass spectrometric (LC-MS/MS) method was used to determine plasma concentrations of lidocaine and prilocaine. Pharmacokinetic analysis of mouse plasma concentrations was carried out by standard non-compartmental methods.

RESULTS

Absorption of both lidocaine and prilocaine was rapid. C_max and AUC values of lidocaine were significantly increased by fourfold and twofold, respectively, in lacerated mouse skin compared to intact skin. Similarly, prilocaine's C_max and AUC values were also increased by 2.5-fold and fourfold, respectively, in lacerated skin compared to intact skin.

CONCLUSION

When Oraqix^® was applied directly into the skin laceration, the plasma concentration of lidocaine and prilocaine was significantly increased as compared to when applied on intact skin. The present study, albeit in mice, indicates that the plasma levels of lidocaine and prilocaine can reach very high levels when the thermosetting gel Oraqix^® is placed directly in wounds.

A randomized placebo-controlled trial to evaluate a novel noninjectable anesthetic gel with thermosetting agent during scaling and root planing in chronic periodontitis patients

Aim:

To study the efficacy of a noninjectable anesthetic gel with a thermosetting agent in the reduction of pain during scaling and root planing (SRP) in untreated chronic periodontitis patients.

Materials and Methods:

This study is a randomized, double-masked, split-mouth, placebo-controlled trial. Thirty patients were enrolled who underwent SRP in a split-mouth (right side/left side) manner. Before commencement of SRP, both quadrants on each side were isolated and had a randomized gel (either placebo or test gel) placed in the periodontal pockets for 30 s. The pain was measured using numerical rating scale (NRS) and verbal rating scale (VRS).

Results:

The median NRS pain score for the patients treated with the anesthetic test gel was 1 (range: 0-4) as opposed to 5 (range: 3-7) in the placebo treated patients. The mean rank of pain score using NRS in test gel was 16.18 as compared to 44.82 in placebo treated sites. Hence, significant reduction in pain was found in test gel as compared to placebo using NRS (P < 0.001). The VRS showed that the majority of patients reported no pain or mild pain with a median of 1 as compared to placebo treated sites with a median of 2 suggestive of moderate pain.

Conclusions:

The NRS and VRS pain scores showed that the side treated with anesthetic gel was statistically more effective than the placebo in reducing pain during SRP.

A brief review on the efficacy of different possible and nonpharmacological techniques in eliminating discomfort of local anesthesia injection during dental procedures

Dental anxiety and fear of needle injection is one of the most common problems encountered by dental practitioners, especially in the pediatric patient. In consequences, it might affect the patient's quality of life. Several methods are suggested to lower the discomfort of local anesthesia injection during dental procedures. Desensitization of injection site is one of the recommended strategies. Among chemical anesthetic topical agents that are effective but might have allergic side effects, using some nonpharmacological and safe techniques might be useful. This study aimed to overview the efficacy of using cooling techniques, mostly by ice or popsicles, warming or pH buffering of drug, and using modern devices to diminish the discomfort of local anesthesia injection during dental procedures.

Liposomal lidocaine gel for topical use at the oral mucosa: characterization, in vitro assays and in vivo anesthetic efficacy in humans

OBJECTIVE

To characterize liposomal-lidocaine formulations for topical use on oral mucosa and to compare their in vitro permeation and in vivo anesthetic efficacy with commercially available lidocaine formulations.

MATERIALS AND METHODS

Large unilamellar liposomes (400 nm) containing lidocaine were prepared using phosphatidylcholine, cholesterol, and α-tocoferol (4:3:0.07, w:w:w) and were characterized in terms of membrane/water partition coefficient, encapsulation efficiency, size, polydispersity, zeta potential, and in vitro release. In vitro permeation across pig palatal mucosa and in vivo topical anesthetic efficacy on the palatal mucosa in healthy volunteers (double-blinded cross-over, placebo controlled study) were performed. The following formulations were tested: liposome-encapsulated 5% lidocaine (Liposome-Lido5); liposome-encapsulated 2.5% lidocaine (Liposome-Lido2.5); 5% lidocaine ointment (Xylocaina®), and eutectic mixture of lidocaine and prilocaine 2.5% (EMLA®).

RESULTS

The Liposome-Lido5 and EMLA showed the best in vitro permeation parameters (flux and permeability coefficient) in comparison with Xylocaina and placebo groups, as well as the best in vivo topical anesthetic efficacy.

CONCLUSION

We successfully developed and characterized a liposome encapsulated 5% lidocaine gel. It could be considered an option to other topical anesthetic agents for oral mucosa.

Anesthetic efficacy of Oraqix® versus Hurricaine® and placebo for pain control during non-surgical periodontal treatment

Objectives: To evaluate the efficacy of Oraqix® during scaling and root planing (SRP) in comparison with 20% benzocaine and placebo. Study Design: 15 patients requiring 4 sessions of SRP were enrolled. For each patient, Oraqix®, Hurricaine®, vaseline or no anesthetic product were randomly assigned each to a quadrant. Treatment pain was evaluated on a 100 mm Visual Analog Scale (VAS) and on a Verbal Rating Scale (VRS). The amount of product administered, the need to re-anesthetise, patient and operator satisfaction and the onset of side-effects were also recorded. Results: Oraqix® was significantly better than nothing, with a reduction of VAS score to 13.3 units, but without significant differences with Vaseline or Hurricaine®. Oraqix® was better in VRS reduction than not using any anesthetic (p=0.001) or using vaseline (p=0.024), but similar to Hurricaine® (p=0.232). Conclusions: Oraqix® effectively controls pain in SRP procedures, with few side-effects and a good acceptance on the part of patients and clinicians.

Key words:Controlled clinical trial, topical anesthetic, scaling and root planing.

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

INTRODUCTION

We investigated the effects of topical anesthesia of the oral mucosa by using an adhesive patch instilled with 2% lidocaine hydrochloride solution.

METHODS

The subjects were 20 healthy adult volunteers who gave written informed consent. Each patient was treated in a randomized crossover fashion with a hemostatic adhesive patch instilled with one of the following agents: 2% lidocaine hydrochloride with 12.5 μg/mL epinephrine, 2% lidocaine hydrochloride, 20% ethyl aminobenzoate, or physiological saline solution. A cotton ball containing 20% ethyl aminobenzoate was also tested. The adhesive patch or cotton ball was placed on the gingivobuccal fold of the maxillary right canine for 2 or 5 minutes. Then, a 33-gauge or 30-gauge needle was inserted to a depth of 2 mm. Insertion pain was evaluated with a visual analog scale (VAS) and a 4-level verbal rating scale immediately after needle removal. Efficacy of analgesia was calculated from the verbal rating scale.

RESULTS

The VAS was lower and the efficacy of analgesia was higher on 33-gauge needle insertion than on 30-gauge needle insertion in all treatments. The VAS was also significantly lower and the efficacy of analgesia was higher in the lidocaine groups than in the other groups. Adding epinephrine did not enhance the anesthetic effect of lidocaine hydrochloride.

CONCLUSIONS

Topical mucosal anesthesia with an adhesive patch containing 2% lidocaine hydrochloride solution is simple and may be more effective than conventional methods.

Liposomal-benzocaine gel formulation: correlation between in vitro assays and in vivo topical anesthesia in volunteers

The aim of the present study was to characterize a liposome-based benzocaine (BZC) formulation designed for topical use on the oral mucosa and to evaluate its in vitro retention and permeation using the Franz-type diffusion cells through pig esophagus mucosa. To predict the effectiveness of new designed formulations during preclinical studies, a correlation between in vitro assays and in vivo efficacy was performed. Liposomal BZC was characterized in terms of membrane/water partition coefficient, encapsulation efficiency, size, polydispersity, zeta potential, and morphology. Liposomal BZC (BL10) was incorporated into gel formulation and its performances were compared to plain BZC gel (B10) and the commercially available BZC gel (B20). BL10 and B10 presented higher flux and retention on pig esophagus mucosa with a shorter lag time, when compared to B20. BZC flux was strongly correlated with in vivo anesthetic efficacy, but not with topical anesthesia duration. The retention studies did not correlate with any of the in vivo efficacy parameters. Thus, in vitro permeation study can be useful to predict anesthetic efficacy during preclinical tests, because a correlation between flux and anesthetic efficacy was observed. Therefore, in vitro assays, followed by in vivo efficacy, are necessary to confirm anesthetic performance.

Effect of lidocaine- and prilocaine-based topical anesthetics on the inflammatory exudates in subcutaneous tissue of rats

The aim of this present study was to evaluate the irritative potential of 2 topical anesthetics used in intrapocket anesthesia for periodontal scaling/root planing when applied in subcutaneous tissue of rats. Sixty animals were divided into 4 groups: group 1, saline solution (control); group 2, poloxamer gel (thermosetting vehicle); group 3, lidocaine and prilocaine poloxamer thermosetting gel; group 4: EMLA, a lidocaine and prilocaine dermatological cream. Injections of 2% Evans blue were administrated intravenously into the lateral caudal vein. In order to analyze vascular permeability, the tested substances were injected intradermally. The rats were sacrificed 3, 6, and 9 hours after injection of the substances. The dorsal skin was dissected and removed. The vascular permeability was evaluated by the measurement of area of dye extravasation and the dye was subsequently extracted after immersion in formamide. Statistical analyses were made by ANOVA with Bonferroni's post hoc test and Pearson correlation. The 2 methods to analyze the exudative phase of the inflammatory process showed statistically significant difference among the groups and periods of evaluation (P < .05). Both methods had a significant correlation (P < .0001). Under the tested conditions, the anesthetic agents showed mild initial inflammatory response when implanted in subcutaneous connective tissue.

A pharmacokinetic study of a topical anesthetic (EMLA® ) in mouse soft tissue laceration

The use of topical anesthesia instead of injection of local anesthetics for managing soft tissue lacerations in the emergency situations may be a relief for both patients and surgeons. Topical anesthesia in the form of a cream eutectic mixture of local anesthetics (EMLA®) containing 2.5% lidocaine and 2.5% prilocaine has been reported as an efficient anesthetic on skin before venipuncture anesthesia and as an alternative to injection anesthesia in some minor surgery situations. The aim of this study was to compare the pharmacokinetics of EMLA® when applied in a laceration with topical skin application in the mouse. A total of 120 Albino Laboratory-bred strain mouse (BALB-c) male mice were divided into three groups with regard to application mode of EMLA®. Group A: with laceration, 48 mice; Group B: on intact shaved skin, 48 mice; Group C: control group (24 mice) with same procedures but without application of EMLA®. Blood levels were collected at 0, 10, 20, 30, 45, 60, 75, and 90 min post-EMLA® application. Plasma sample analysis was carried out by employing liquid chromatography coupled with tandem mass spectrometric (LC-MS/MS) method, and the pharmacokinetic analysis of the mouse plasma samples was estimated by standard non-compartmental methods. The pharmacokinetic parameters of lidocaine and prilocaine were significantly altered following EMLA® application to lacerated mouse skin in contrast to intact skin. The absorption of lidocaine and prilocaine was rapid following application of EMLA® to lacerated and intact mouse skin. Maximum drug plasma concentration (C(max) ) and area under the drug plasma concentration-time curve (AUC) values of lidocaine were significantly increased by 448.6% and 161.5%, respectively, following application of EMLA to lacerated mouse skin in comparison with intact mouse skin. Similarly, prilocaine's C(max) and AUC values were also increased by 384% and 265.7%, respectively, following EMLA application to lacerated mouse skin, in contrast to intact skin. Further pharmacokinetic studies on different carriers of lidocaine/prilocaine are warranted before any firm conclusions for the clinic can be drawn.

The effectiveness of Oraqix versus TAC(a) for placement of orthodontic temporary anchorage devices

OBJECTIVE

To test the hypothesis that there is no difference in the actions and effectiveness of topical anesthetics TAC Alternate (TAC((a))) and Oraqix in placing temporary anchorage devices (TADs).

MATERIALS AND METHODS

Each topical anesthetic was placed on opposing sides in the maxilla or mandible using blinded applicators for 3-9 minutes followed by the TAD placement. A total of 21 patients ranging from 10-25 years old were studied. During the procedure the primary investigator (PI) used the sound, eye, and motor scale to measure the movements elicited by the patient. The PI also noted the time taken for the topical anesthetic to be effective and the amount that was applied. Following the placement of the TADs, the patients were given the Wong-Baker FACES Scale and the Visual Analog Scale to rate the degree of discomfort. The nonparametric Wilcoxon signed-rank test was used to test the effectiveness of the treatments based on the three ordinal scales, the dosage, and the onset time.

RESULTS

The time it took for the TAC((a)) to provide adequate anesthesia averaged 4.43 minutes and for Oraqix the time was 6.33 minutes (P = .00). The minimum dosage of TAC((a)) to provide adequate anesthesia averaged 0.25 mL, and for Oraqix the minimum dosage averaged 0.31 mL (P = .00).

CONCLUSIONS

The hypothesis was rejected. TAC((a)) was more effective than Oraqix in placing TADs with a recommended dose of 0.20-0.30 mL and a minimum application time of 3 minutes.

Liposomal delivery system for topical anaesthesia of the palatal mucosa

An effective topical agent to reduce pain during local anaesthesia of the palate is not yet available. The aim of the present study was to evaluate the efficiency of liposome-encapsulated ropivacaine in different concentrations for topical anaesthesia of the palatal mucosa. In this single-blinded, placebo-controlled, crossover study 40 (20 male) healthy volunteers were randomised to be given: liposome-encapsulated 2% ropivacaine, liposome-encapsulated 1% ropivacaine, a eutectic mixture of 2.5% lidocaine and 2.5% prilocaine (EMLA), and liposomal placebo gel, topically on to the palatal mucosa of the right canine region for 5 min each, at four different sessions. Pain associated with insertion of a 30G needle, and with injection of a local anaesthetic, was rated on a visual analogue scale (VAS). The effect of liposomal ropivacaine 1% and 2% did not differ from that of placebo (p=0.3 and p=0.1, respectively) in reducing pain during insertion of the needle. Lower VAS were obtained with EMLA. In this group VAS were lower in women than men (p=0.007). There was no difference in VAS among groups (p=0.3) as far as injection of the local anaesthetic was concerned. In conclusion, liposomal-encapsulated ropivacaine formulations did not reduce the pain of insertion of a needle into the palatal mucosa. None of the anaesthetic formulations tested, including the positive control (EMLA), were effective in reducing the pain of an injection of local anaesthetic compared with placebo.

Effect of eutectic mixture of local anesthetics on pain perception during scaling by ultrasonic or hand instruments: a masked randomized controlled trial

BACKGROUND

The aims of this study are to evaluate the efficacy of a eutectic mixture of local anesthetic (EMLA) cream on pain perception during scaling and to compare the intensities of pain provoked by hand and ultrasonic instruments.

METHODS

Forty subjects with chronic gingivitis or periodontitis were enrolled in the study. In this randomized, split-mouth, controlled, masked clinical trial, each of the four quadrants in subjects was randomly assigned to receive one of the following protocols: scaling with an ultrasonic scaler with or without the application of the EMLA cream or scaling with a Gracey curet with or without the application of the EMLA cream. Pain levels after each quadrant of scaling were assessed with a visual analog scale (VAS; 0 to 100 mm) and verbal rating score (VRS; 0 to 4). All subjects were recalled to detect any complications after 24 hours.

RESULTS

The mean VAS and VRS when EMLA cream was applied (18.39 ± 14.47 mm and 0.95 ± 0.69) were significantly lower (P <0.001 for VAS and VRS) compared to when EMLA cream was not used (26.54 ± 16.46 mm and 1.30 ± 0.75). The mean VAS and VRS of the ultrasonic scaler group (20.43 ± 16.40 mm and 0.98 ± 0.76) were significantly lower (P = 0.024 for VAS; P = 0.003 for VRS) than those of the Gracey curet group (24.50 ± 15.17 mm and 1.28 ± 0.69). None of the subjects showed adverse effects after EMLA-cream application.

CONCLUSION

Although most patients experienced limited pain during scaling, a significant reduction of pain is achieved by using EMLA cream and ultrasonic scaler.

Liposomal encapsulation improves the duration of soft tissue anesthesia but does not induce pulpal anesthesia

STUDY OBJECTIVE

To compare the topical and the pulpal anesthesia efficacy of liposomal and plain benzocaine formulations.

DESIGN

Double-blinded, randomized crossover study.

SETTING

University ambulatory dental center.

PATIENTS

30 ASA physical status I volunteers.

INTERVENTIONS

Volunteers received, in three different sessions, topical application of liposome-encapsulated 10% benzocaine (LB10), 10% benzocaine gel (B10), and 20% benzocaine gel (B20) in the right maxillary canine mucobuccal fold.

MEASUREMENTS

Pain associated with the needle insertion was rated by visual analog scale (VAS) and the duration of topical anesthesia was recorded. Pulpal anesthesia was evaluated using an electric pulp tester.

MAIN RESULTS

VAS values (median, 1st - 3rd quartiles) were 17 cm (11 - 25), 14 cm (3 - 22), and 21 cm (9 - 21) for B10, LB10, and B20, respectively. No differences were noted among the groups (Friedman test; P = 0.58). Soft tissue anesthesia was also not different. The LB10 [10 (8 - 12) min] showed longer soft tissue anesthesia (Friedman test; P < 0.01) than the other agents [B10 = 8 (5 - 10) min, and B20 = 7 (6 - 9) min]. None of the topical benzocaine formulations tested induced pulpal anesthesia.

CONCLUSIONS

The encapsulation of benzocaine into liposome increased the duration of soft tissue anesthesia. However, it did not induce pulpal anesthesia.

Bioadhesive films containing benzocaine: correlation between in vitro permeation and in vivo local anesthetic effect

PURPOSE

The aim of this work was to develop anesthetic bioadhesive films containing benzocaine and study their in vitro skin permeation and in vivo performance, in comparison with commercial formulations.

METHODS

Films containing 3% and 5% w/w of benzocaine were prepared and characterized by weight, drug content, thickness and morphology. In vitro permeation assays were performed in vertical diffusion cells using full-thickness pig ear skin as barrier. Intensity and duration of analgesia were evaluated in rats by tail-flick test, and skin histological analysis was carried out.

RESULTS

Tail-flick test showed that the duration of benzocaine-induced analgesia was significantly prolonged with the films compared to commercial creams, in agreement with the higher in vitro permeation. Histological analysis of the rat tail skin did not reveal morphological tissue changes nor cell infiltration signs after application of the commercial creams or films.

CONCLUSIONS

Results from our study indicate that the films developed in this work can be considered as innovative dermal/transdermal therapeutic systems for benzocaine local delivery.