Speed of Injection Influences Efficacy of Inferior Alveolar Nerve Blocks: A Double-Blind Randomized Controlled Trial in Volunteers

Visuo-Haptic VR and AR Guidance for Dental Nerve Block Education

The inferior alveolar nerve block (IANB) is a dental anesthetic injection that is critical to the performance of many dental procedures. Dental students typically learn to administer an IANB through videos and practice on silicone molds and, in many dental schools, on other students. This causes significant stress for both the students and their early patients. To reduce discomfort and improve clinical outcomes, we created an anatomically informed virtual reality headset-based educational system for the IANB. It combines a layered 3D anatomical model, dynamic visual guidance for syringe position and orientation, and active force feedback to emulate syringe interaction with tissue. A companion mobile augmented reality application allows students to step through a visualization of the procedure on a phone or tablet. We conducted a user study to determine the advantages of preclinical training with our IANB simulator. We found that in comparison to dental students who were exposed only to traditional supplementary study materials, dental students who used our IANB simulator were more confident administering their first clinical injections, had less need for syringe readjustments, and had greater success in numbing patients.

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.

Overcoming local anesthesia failure during routine dental treatments in children

BACKGROUND

Local anesthesia (LA) during routine dental treatment in children fails in 5%-35% of first attempts. No data, however, are available on the success rates of subsequent attempts.

AIM

To evaluate the effectiveness of primary, secondary, and tertiary LA attempts (P-LA, S-LA, and T-LA, respectively) for anesthetizing molars during routine dental treatments in children.

DESIGN

We retrospectively analyzed dental records of all children (2-18 years) who had been administered LA for the treatment of primary or permanent molars by a single paediatric dentist, between 2011 and 2022. All LAs were delivered using a computer-controlled local anesthetic delivery (CCLAD) system.

RESULTS

The failure rate of P-LA in 1312 molars was 13% and correlated with age (p < .001), type of tooth (p < .001), type of treatment (p < .001), and treated arch (p < .001). The effectiveness of S-LA for buccal infiltration, intrasulcular, inferior alveolar nerve block, greater palatine nerve block (GPNB), posterior superior alveolar nerve block (PSANB), or a combination of the last two was 50%, 87.2%, 66.7%, 63.6%, 33.3%, and 100%, respectively, and was not significantly associated with age or the type of tooth, treatment, or P-LA.

CONCLUSION

The optimal choice of S-LA for anesthetizing maxillary molars was a combination of PSANB and GPNB, whereas for mandibular molars, it was IS-CCLAD system.

Clinical Application of Inferior Alveolar Nerve Block Device for Safe and Secure IANB by Any Operator

The inferior alveolar nerve block (IANB) is an established technique with a success rate of 60-80%; however, large errors have been reported among operators. Some dentists do not prefer to use IANB because of the risk of complications. Nevertheless, it is a useful technique for pain control, and a secure IANB offers significant benefits to operators and patients. This case series study aimed to investigate the efficacy of the "IANB Device," a nerve block guide for IANB, and the adverse events associated with its use in clinical practice. IANB was performed using the device on five patients who had undergone detailed computed tomography examination for chronic orofacial pain in the third division of the trigeminal nerve. Lidocaine 1% (1 mL, no adrenaline added) was used as the local anesthetic. IANB was performed by three dentists with 2, 5, and 11 years of experience in orofacial pain treatment. Thus, the data were collected in triplicate for each patient. The primary endpoints were whether adjustment of the IANB device was required, changes in the sensation threshold of the lower lip, the time to disappearance of pain, the presence or absence of tongue sensation ("Do you have numbness in your tongue?": "Yes/No"), and discomfort (visual analog scale). The incidence of any other adverse events was recorded. The procedure was judged to be successful if the pain disappeared and an elevation in the sensation threshold of the lower lip was observed. Adjustment of the IANB device was not required in any patient. A significant elevation in the sensation threshold of the lower lip and the disappearance of pain were observed in all patients. Three of the five patients reported experiencing tongue numbness. Discomfort with the use of the IANB device was less than 30 mm on the visual analog scale. No notable complications were observed. The appropriate type, concentration, and dosage of the local anesthetic must be considered during general dental treatment and oral surgical procedures. Our findings suggest that the IANB device is useful for eliminating errors between operators, enhancing safety, and improving the success rate.

Does a New Modification of the Two-Step Injection Technique for Inferior Alveolar Nerve Block Reduce Pain Compared to the Conventional Technique? A Randomized Clinical Trial

Background. The ability to control pain is an essential part of dental procedures and the need for optimal pain control and reduction of discomfort is the primary concern of every dentist. This study aims to compare the pain and vital signs during inferior alveolar nerve block between conventional and a new modification of the two-step injection techniques. Methods. In this institutional single-blind randomized clinical trial, attendees of dental school at Mazandaran University of Medical Sciences from February to May 2022 were included. Inclusion criteria were 20–60 years old and healthy (ASA1) individuals who were willing to participate in this study. Individuals who were taking medications affecting their understanding of pain and patients with active infections at the injection site were excluded. These individuals were divided into two groups. First, superficial anesthesia was performed and afterward, conventional and two-step injection techniques were performed. For the two-step injection method, 6 mm of the needle was injected into the mucosa and one-third of the local anesthetic solution was released from the computer-controlled injection toolkit. Afterward, a 25 mm 30-gauge needle was reinserted into the previous hole delivering the remaining local anesthetic. The pain during injection was measured by a patient-reported numerical rating scale (NRS). Moreover, vital signs were monitored immediately before and after the injection. Kolmogorov–Smirnov test, Mann–Whitney U test, independent T-test, and Fisher’s exact χ2 test were performed for statistical analysis (α = 0.05). Results. This study involved 32 adults aged between 20 and 50 years old with 1 : 1 female/male sex distribution. The pain score was significantly higher in the conventional injection technique compared to the two-step injection technique in all sex and age groups. There were no significant differences in vital signs between the conventional and two-step injection techniques. There was no significant difference in the mean pain scores of females and males, regardless of their injection techniques. Conclusion. Utilizing the two-step injection technique in patients for inferior alveolar block reduces pain during injection without altering patients’ vital signs significantly. This trial is registered with IRCT20220106053646N1.

Anesthetic efficacy of supplemental buccal infiltration versus intraligamentary injection in mandibular first and second molars with irreversible pulpitis: a prospective randomized clinical trial

Background

To compare the anesthetic efficacy of supplemental buccal infiltration (BI) (1.7 ml) versus intraligamentary (IL) injection containing 0.4 ml of 4% articaine with 1:100.000 epinephrine after an inferior alveolar nerve block (IANB) with 1.7 ml 2% lidocaine in the first and second mandibular molars diagnosed with irreversible pulpitis (IP).

Methods

One hundred subjects diagnosed with IP of either the mandibular first (n = 50) or second molars (n = 50) and failed profound anesthesia following an IANB were selected. They randomly received either the IL or BI techniques of anesthesia. Pain scores on a 170 mm Heft-Parker visual analog scale were recorded initially, before, and during supplemental injections. Furthermore, pulse rate was measured before and after each supplemental injection. During the access cavity preparation and initial filing, no or mild pain was assumed to indicate anesthetic success. The chi-square test, Mann-Whitney U test, and independent samples t-test were used for the analyses.

Results

The overall success rates were 80% in the IL group and 74% in the BI group, with no significant difference (P = 0.63). In the first molars, there was no significant difference between the two techniques (P = 0.088). In the second molars, IL injection resulted in a significantly higher success rate (P = 0.017) than BI. IL injection was statistically more successful (P = 0.034) in the second molars (92%) than in the first molars (68%). However, BI was significantly more successful (P = 0.047) in the first molars (88%) than in the second molars (64%). The mean pulse rate increase was significantly higher in the IL group than in the BI group (P < 0.001).

Conclusions

Both the IL and BI techniques were advantageous when used as supplemental injections. However, more favorable outcomes were observed when the second molars received IL injection and the first molars received BI.

Pain perception following computer-controlled versus conventional dental anesthesia: randomized controlled trial

Background

The administration of local anesthesia (LA) in dental practice requires an injection which is the leading cause of patients’ fear and anxiety. Computer-controlled local anesthetic injector, designed to reduce the pain of performing local anesthesia by controlling the speed of injection. This single-blind randomised control trial aimed to compare the pain perception after computer-controlled local anesthesia (CCLA) and conventional LA.

Methods

Dental students were both test and operator group versus an experienced dentist as additional operator of the LA. Data were collected regarding gender, age, medical condition, smoking habits. Additionally, operator feedback about the handling, pain at insertion and during infiltration, excitement (Dental Anxiety Scale), and complications were assessed.

Results

Out of the 60 included participants, the majority were females (n = 41; 68.3%), medically healthy (n = 54; 90%), and did not receive medications (n = 54; 90%). While the participating students administered 62 (51.7%) injections, the experienced dentist administered 58 (48.3%) injections. The difference in pain perception on puncture between CCLA and conventional injections was not statistically significant (Sig. = 0.285); however, pain perception during injection was significantly different (Sig. = 0.029) between CCLA (1.65 ± 1.93) and conventional injections (2.49 ± 2.31).

Conclusion

The professional experience influenced the pain perception while applying the LA. CCLA did not reduce pain on puncture significantly; however, pain perception during the injection was significantly reduced in the case of using CCLA devices compared to the conventional syringe.

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.

Needle tip deformation in local dental anesthesia - A technical note

INTRODUCTION

The aim of this in vitro study was to investigate the mechanical deformation rate of dental cannula tips after injection simulation in a new developed animal model.

MATERIALS AND METHODS

A new mechanical device was designed to define forces (100 g for 60 s) to impact a pigs jaw bone with different cannulas (25-Gauge/27-Gauge) from dental local anaesthesia syringes. 8 different products (100 cannulas each) were evaluated. Cannula tips were examined for deformation under the digital microscope VHX-100 (500-fold magnification).

RESULTS

27G and 27G free flow showed a significantly lower likelihood of bending (OR 0.05; p = 0.0001). Comparing 27G cannulas of the same outer diameter but different inner diameter, large inner diameter produced a significantly higher deformation rate than those of cannulas with a standard inner diameter. 12-38% of the cannulas showed manufacturing defects and production-related deformation.

CONCLUSIONS

Cannula deformation seems to depend on the inner diameter, bevel and cutting profile. Multiple use of the same cannula could result in more pronounced deformation, increasing the risk of complications during local anesthesia.

Needle-free Mental Incisive Nerve Block:In vitro, Cadaveric, and Pilot Clinical Studies

The present study aimed to optimize Needle-Free Liquid Jet Injection (NFLJI) for Mental Incisive Nerve Blocks (MINB) and evaluate its clinical safety and feasibility. A MINB protocol was developed and optimized by series of NFLJI experiments in soft tissue phantoms and cadavers, then validated in two pilot Randomized Controlled Trials (RCT). The NFLJI penetration depth was found to be directly proportional to the supply pressure and volume. High-pressure NFLJIs (620 kPa or above) created maximum force and total work significantly greater than needle injections. Low-pressure NFLJIs (413 kPa), however, produced results similar to those of needle injections. Additionally, high-pressure NFLJIs created jet impingement pressure and maximum jet penetration pressure higher than low-pressure NFLJIs. Pilot RCTs revealed that high-pressure NFLJI caused a high risk of discomfort (60%) and paresthesia (20%); meanwhile, low-pressure NFLJI was less likely to cause complications (0%). The preliminary success rates of MINB from cadavers using NFLJIs and needles were 83.3% and 87.5%. In comparison, those from RCTs are 60% and 70%, respectively. To conclude, NFLJI supply pressure can be adjusted to achieve effective MINB with minimal complications. Furthermore, the cadaver study and pilot RCTs confirmed the feasibility for further non-inferiority RCT.

Needle-free injection: Dental infiltration anesthesia

This study aimed to develop an optimal Needle-Free Liquid Jet Injection (NFLJI) technique for dental infiltration anesthesia and evaluate its clinical safety and feasibility. The fluid dynamics of NFLJI in the dentoalveolar region were investigated using soft tissue phantoms supported by rigid glass. NFLJIs were performed at different incident angles and recorded using a high-speed camera. Accordingly, an optimal NFLJI for infiltration anesthesia was developed and validated on cadavers, then assessed in two pilot Randomized Controlled Trials (RCT): one for validating the safety of optimal NFLJI technique, the other for evaluating its feasibility and safety. High-speed videos showed that perpendicular NFLJIs induced significantly more regurgitation than oblique NFLJIs, which was confirmed in cadavers. Clinical trials revealed that perpendicular NFLJIs induced a high risk of bleeding (83.3%) and laceration (83.3%), whereas oblique NFLJIs induced a low risk of bleeding (33.3%) and laceration (16.7%). Moreover, the preliminary success rates of oblique NFLJIs and needle injections were both 83.3%. The recruitment took 3-5 weeks with a rate of 100%. Oblique NFLJIs could be a promising approach for dental infiltration anesthesia, causing minimal drug regurgitation with a relatively low risk of complication. The pilot RCTs confirmed the feasibility for conducting a non-inferiority RCT.

Anaesthetic Efficacy of 4% Articaine in Comparison with 2% Lidocaine as Intraligamentary Injections after an Ineffective Inferior Alveolar Nerve Block in Mandibular Molars with Irreversible Pulpitis: A Prospective Randomised Triple-Blind Clinical Trial

The objective of the current study was to compare the anaesthetic efficacy of supplemental intraligamentary (IL) injection of 4% articaine with that of 2% lidocaine in the mandibular first and second molars with irreversible pulpitis after an ineffective inferior alveolar nerve block injection (IANB) using the same anaesthetic in a randomised triple-blind clinical trial. Seventy-six adult patients, who were diagnosed with irreversible pulpitis in the mandibular first or second molars, were divided into 2 groups and received IANB randomly. In patients with lip numbness, anaesthesia was evaluated with the cold and electrical pulp (EPT) tests, and if the reported number on EPT was below 100, supplemental IL injection was administered using the same anaesthetic. The teeth were retested after 5 minutes. The Heft-Parker visual analogue scale was used to evaluate pain after IANB and IL injections. Statistical analysis was performed using repeated measures ANOVA, chi-square, and independent-sample and paired-sample t-tests. The results showed that there was no significant difference in the success rates of supplemental IL and IANB injections between articaine and lidocaine. Furthermore, there was no significant difference in the success rates of supplemental IL injection with lidocaine between the mandibular first and second molars. However, there was a significant difference in the success rates of supplemental IL injection with articaine between the mandibular first and second molars. Moreover, supplemental IL injections indicated no significant difference in the anaesthetic efficacy between articaine and lidocaine; nevertheless, they were more effective in the mandibular second molars, especially with articaine.

Do length and gauge of dental needle affect success in performing an inferior alveolar nerve block during extraction of adult mandibular molars? A prospective, randomized observer-blind, clinical trial

OBJECTIVE

Association between length and gauge of dental needle and success rate and pain perception during an inferior alveolar nerve block (IANB) has not been investigated using a randomized clinical trial (RCT). This RCT aimed to compare the success rate of IANB and perceived pain using 27- or 30-gauge needles for the extraction of adult mandibular molars.

MATERIAL AND METHOD

A prospective RCT was conducted on two hundred and twelve adult patients requiring extraction of mandibular molars using standard methods as described by Malamed with 1.8 ml of 2% lidocaine with 1:80,000 adrenaline. One hundred six patients received IANB using 27-gauge needles (32 mm × 0.2 mm) and one hundred six patients received IANB using 30-gauge needles (25 mm × 0.15 mm). Predictor variables were 27-gauge and short and 30-gauge. Outcome variables were the success rate of IANB and pain perception during injection using a visual analogue scale.

RESULTS

There was a highly significantly increase in the success of IANB using 27-gauge needle (95.28%) versus 30-gauge needle (41.51%) (P = 0.001). There was a significant increase in pain perception for patients who received IANB by shorter and thinner needle (30-gauge) when compared to the long and thicker needle (27-gauge).

CONCLUSION

This RCT demonstrated that 27-gauge needle seems to be associated with a higher success rate of IANB and lower pain perception during injection when compared to 30-gauge needle in the extraction of adult mandibular molars when compared to 30-gauge needles.

CLINICAL RELEVANCE

For adult patients, when thickness of soft tissue to be penetrated is essential to achieve bony contact, long or large gauge dental needle is preferred to get a higher success rate of IANB with less pain perception during injection.

Effect of augmented reality simulation on administration of local anaesthesia in paediatric patients

BACKGROUND

Augmented reality (AR) is a simulation of a three-dimensional environment created using hardware and software that provides the user with realistic experiences and ability to interact. The aim of the study was to evaluate the impact of AR simulator on the perception of learning and acute stress level in students administering local anaesthesia to paediatric patients relative to standard teaching methods.

MATERIAL AND METHODS

The prospective study included 21 fourth- and fifth-year students enrolled in 5-year dental programme. In addition to conventional training, the students of the study group used the augmented reality simulator in a dental office 2 hours weekly in 2 weeks. The level of salivary cortisol was measured before and after the anaesthetic procedure as one of the indicators of acute stress.

RESULTS

A statistically significant shorter time to perform infiltrative anaesthesia technique for the anterior superior alveolar nerve was observed in students using the AR technique (28.91 ± 9.06 seconds in the study group and 39.80 ± 9.29 seconds in the control group). The level of cortisol before and after anaesthesia was statistically significant in all subjects (cortisol concentration was 0.53 μg/dL before anaesthesia and 2.44 μg/dL after the procedure); however, there was no statistically significant difference between the groups.

CONCLUSION

The AR concept may influence better manipulation and control of the syringe in students administering their first anaesthetic injection to paediatric patients, but may not reduce acute stress.

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.

The effect of inferior alveolar nerve block anesthesia of 4% articaine and epinephrine 1:100,000 on blood flow and anesthesia of human mandibular teeth

Background/purpose

Local anesthetics and anesthetic techniques affect the patterns of pulpal blood flow (PBF) and pulpal anesthesia in human teeth. This study aimed to determine PBF changes and pulpal anesthesia of intact mandibular first molars and canines after administration of 4% articaine with epinephrine 1:100,000 using inferior alveolar nerve block (IANB).

Materials and methods

Ten healthy subjects received IANB of 4% articaine with epinephrine 1:100,000. Laser Doppler flowmetry and electrical pulp testing were combined to assess PBF changes and pulpal anesthesia of intact mandibular first molars and canines. The data were analyzed using one-way repeated-measures analysis of variance and Student-Newman-Keuls test.

Results

IANB with 4% articaine and epinephrine 1:100,000 did not have any significant change in PBF for the first 20 min post injection in mandibular first molars, and for 45 min post injection in the canines (P > 0.05). However, a hyperemic response occurred during 25-60 min post injection in the molars, and between 60 and 75 min post injection in the canines (P < 0.05). Thereafter, the PBF in both teeth returned to the baseline. Onset of pulpal anesthesia was 8.60 ± 2.12 min in the molars, and 9 ± 1.94 min in the canines. Duration of pulpal anesthesia was 82.40 ± 41.56 min in the molars, and 84 ± 47.40 min in the canines.

Conclusion

In case of successful IANB, 4% articaine and epinephrine 1:100,000 caused insignificant changes in PBF up to 30 min but a hyperemic response at later time points. Thereafter, the PBF returned to the baseline.

Comparison of Patient Comfort During the First Stage of Conventional Versus Modified Two-Stage Inferior Alveolar Nerve Blocks in Pediatric Patients

Our aim was to compare the comfort of pediatric patients during the first stage of the conventional 2-stage inferior alveolar nerve block (IANB) versus the modified 2-stage IANB. This was a parallel group, single-blinded, randomized controlled trial. Pediatric patients meeting the inclusion criteria were randomly allocated to 1 of the 2 groups receiving IANB, group 1 (31 subjects) utilized a conventional 2-stage technique, and group 2 (33 subjects) utilized a modified 2-stage approach. Patient comfort was assessed indirectly by 2 observers using the Face, Legs, Activity, Cry, Consolability (FLACC) scale during the first stage of the injections. FLACC score data between the 2 groups were analyzed using the chi-square test, and interobserver reliability was measured using kappa statistics. During the first stage of the injections, lower FLACC scores of 0 indicating a relaxed/comfortable patient experience were found in 57.6% of group 2 subjects compared with only 25.8% group 1 subjects, which was a statistically significant difference (p-value .013). Interobserver reliability assessed using kappa coefficients (κ = 0.812) indicated excellent agreement. FLACC scores for the pediatric patients during the first stage of the modified 2-stage IANB technique were significantly lower than during the first stage of the conventional 2-stage IANB technique.

Inferior Alveolar Nerve Block Injection Pain Using a Computer-Controlled Local Anesthetic Device (CCLAD): A Prospective, Randomized Study

There is evidence that the Computer-Controlled Local Anesthetic Device (CCLAD) decreases the pain of oral injections. The purpose of this study was to evaluate injection pain of the inferior alveolar nerve block (IANB) using the CCLAD in an upright position versus a supine position. Additionally, we evaluated solution deposition pain with the CCLAD when compared to previous studies using a traditional syringe. One hundred ten asymptomatic subjects were randomly given IANBs using 2% lidocaine with 1:100,000 epinephrine while in an upright sitting position and supine position, at 2 different appointments, spaced at least 2 weeks apart. Each subject rated the pain for needle insertion, needle placement, and solution deposition on a Heft-Parker visual analogue scale. Pain ratings were compared between the upright and supine positions using a repeated-measures analysis of variance with post hoc testing using the Tukey-Kramer procedure. Moderate to severe pain was reported by 10% to 13% of the patients for needle insertion, 74% to 75% for full needle placement, and 8% to 10% for solution deposition. There was no significant difference between groups for phases of the injection. When comparing the injection phases within the groups, the needle placement phase of the injection was statistically more painful than both the needle insertion phase and solution deposition phase ( p = .0001). Using the CCLAD, IANB injection pain of the supine and upright positions was not statistically different. Needle placement was the most painful phase of the injection. Solution deposition pain was less with the CCLAD when compared to other studies of the IANB using a traditional syringe.

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.

Is Articaine More Potent than Mepivacaine for Use in Oral Surgery?

OBJECTIVES

To investigate the potency and speed of action of 4% articaine and 2% mepivacaine for maxillary teeth extractions.

MATERIAL AND METHODS

Ninety-four patients, aged between 16 to 70 years old, were recruited in this study. Two regimens were randomly administered over one visit. Patients of treatment group 1 received mepivacaine 2% with 1:100,000 adrenaline, whereas treatment group 2 - articaine 4% with 1:100,000 adrenaline. The onset time of pulp anaesthesia for maxillary teeth indicated for extraction was determined by electronic pulp testing. At any point of trial (10 minutes), the anesthetized tooth becomes unresponsive for maximal pulp stimulation (64 reading), the extraction was carried out.

RESULTS

In this study, 85 patients had successful local anaesthetic followed by extraction within the study duration time (10 min). However, 5 patients had failed dental extraction (4 in mepivacaine group and 1 in articaine group). Patients in the articaine buccal infiltration group recorded faster onset time of action regarding anaesthesia and teeth extraction than patients in mepivacaine buccal infiltration group (P = 0.03).

CONCLUSIONS

Articaine is an effective anaesthetic with a rapid onset, comparable to mepivacaine in infiltrative techniques used for maxillary teeth extraction. However, articaine has clinically achieved faster dental anaesthesia and earlier teeth extraction than mepivacaine. So, articaine can be the local anaesthetic of first choice in oral surgery.

Is mepivacaine as effective as lidocaine during inferior alveolar nerve blocks in patients with symptomatic irreversible pulpitis? A systematic review and meta-analysis

This study aimed to compare the effectiveness of mepivacaine and lidocaine for pulpal anaesthesia and pain control when administered via an inferior alveolar nerve block during the root canal treatment of mandibular molars in patients with symptomatic irreversible pulpitis. A research protocol was developed and registered in PROSPERO. The systematic search was conducted during May 2017 in eight databases. The studies were selected based on inclusion and exclusion criteria. Two examiners analysed the sample independently, decided the eligibility for inclusion and classified the articles according to their quality. Statistical analysis was performed with Mantel-Haenszel and I-square (I² ) tests considering a confidence interval of 95%. The initial sample consisted of 1130 articles, out of which four were eligible. The articles were published between 1993 and 2016. For both pulpal anaesthesia and pain control, there was no significant difference between mepivacaine and lidocaine (P = 0.843, I²  = 0%, and P = 0.183, I²  = 21.1%, respectively). Mepivacaine and lidocaine were similarly effective for pulpal anaesthesia and pain control after inferior alveolar nerve blocks for root canal treatment.

Effect of relative head position on the anesthetic efficacy of inferior alveolar nerve block during endodontic treatment of patients with irreversible pulpitis

Background

The purpose of this prospective randomized single-blind clinical trial was to evaluate the effect of tilting the head on the anesthetic efficacy of inferior alveolar nerve block (IANB) in patients with symptomatic irreversible pulpitis.

Methods

Ninety-two patients were divided into two groups: the first group received IANB and the head was tilted in the direction of the block for 15 min, whereas the second group received IANB and the head was tilted to the opposite side. Access cavity preparation was initiated after 15 min. Success was defined as no pain or faint/weak/mild pain during endodontic access preparation and instrumentation. The anesthetic success rates were analyzed by Pearson chi-square test at 5% significance levels.

Results

The same side position and opposite side position yielded 41% and 30% anesthetic success rates, respectively; there was no significant difference between the two sides.

Conclusions

Relative head position has no effect on the anesthetic success rate of IANB.

Comparação das propriedades anestésicas em duas técnicas anestésicas distintas para molares inferiores

Resumo Introdução O medo de sentir dor é um dos principais motivos pelos quais muitos pacientes evitam submeter-se a tratamento dentário. Em vários procedimentos odontológicos, o uso de anestésicos locais se faz necessário. O aparelho Morpheus® propõe a introdução da agulha sem dor e anestesia satisfatória, com uso de menor volume de anestésico local. Quando há necessidade de intervenção em molares e pré-molares inferiores, é preconizado o uso deste aparelho para técnica intrasseptal CaZOE, substituindo o bloqueio do nervo alveolar inferior tradicional (BNAI). Objetivo O presente trabalho de pesquisa configurou-se como um estudo randomizado, duplo cego e cruzado, cujo objetivo foi avaliar as propriedades anestésicas através da técnica intrasseptal CaZOE e da técnica convencional do bloqueio do nervo alveolar inferior (BNAI). Material e método Os procedimentos anestésicos foram realizados em duas sessões, por um único operador previamente treinado. Assim, foram avaliados parâmetros físicos, saturação periférica de O2, ansiedade, sensibilidade dolorosa, eficácia, tempo de latência e duração da anestesia em cada uma das técnicas, sendo então os respectivos dados comparados. Resultado Não houve diferenças significativas quanto aos parâmetros físicos e à saturação periférica de O2. A técnica intrasseptal CaZOE apresentou maior taxa de sucesso anestésico, menor tempo de latência, menor tempo de duração e menor desconforto na execução, quando comparada ao BNAI. Conclusão Inserir a injeção eletrônica na rotina da clínica odontológica pode proporcionar maior conforto aos pacientes submetidos à anestesia local e diminuir o abandono dos tratamentos odontológicos por medo e ansiedade associados à anestesia local.

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.

Effective anaesthesia of the acutely inflamed pulp: part 2. Clinical strategies

Achieving profound pulpal anaesthesia in a mandibular molar diagnosed with irreversible pulpitis can be argued to be the most testing of dental anaesthetic challenges. Following discussion on the possible reasons for this occurrence in part 1, part 2 outlines the various local anaesthetic techniques that practitioners can use to overcome the acutely inflamed mandibular molar. They should then be able to apply these same principles to help anaesthetise any other tooth presenting with an acutely inflamed pulp. Techniques are discussed in detail along with key variables that have been associated with having an impact on the anaesthetic efficacy. This is to bring to light factors that can aid anaesthetic success as well as dispel common misnomers.

Comparação do nível álgico no bloqueio do nervo alveolar inferior através de duas técnicas distintas

Resumo Introdução O bloqueio do nervo alveolar inferior está entre as anestesias mais utilizadas e importantes da Odontologia; porém, não há estudos que comparem a anestesia eletrônica (Morpheus) e a anestesia tradicional manual, utilizando a seringa Carpule. Objetivo Avaliar comparativamente dois sistemas de anestesia com relação à sensibilidade dolorosa durante e após a anestesia, com a administração de lidocaína 2% associada à epinefrina 1:100.000, na técnica anestésica para o nervo alveolar inferior. Material e método Este ensaio clínico foi executado de modo randomizado, cruzado e duplamente cego, envolvendo 30 voluntários, que necessitavam de tratamento odontológico e que se submeteram ao bloqueio do nervo alveolar inferior, utilizando a seringa tipo Carpule na primeira sessão e o injetor de velocidade controlada Morpheus, o qual foi realizado em duas sessões, com intervalo de pelo menos duas semanas entre cada sessão. Ao final de cada sessão, foi aplicada a Escala Visual Analógica (EAV), para avaliação da sensibilidade dolorosa à injeção. Resultado A comparação entre os métodos revelou que o convencional mostrou induzir maiores valores na EAV do que o Morpheus. O teste do Qui-Quadrado, para proporções esperadas iguais, mostrou que a técnica com Morpheus obteve maior (p=0,0062) preferência do que a convencional. Conclusão No conjunto, os dados revelam que a técnica empregando o Morpheus foi superior à convencional nos três momentos. A execução da anestesia realizada com Morpheus mostrou ser mais confortável e ter aceitação e maior preferência dos voluntários.

Effect of Preoperative Pain on Inferior Alveolar Nerve Block

The present study tested the hypothesis that the amount and severity of preoperative pain will affect the anesthetic efficacy of inferior alveolar nerve block (IANB) in patients with symptomatic irreversible pulpitis. One-hundred seventy-seven adult volunteer subjects, actively experiencing pain in a mandibular molar, participated in this prospective double-blind study carried out at 2 different centers. The patients were classified into 3 groups on the basis of severity of preoperative pain: mild, 1-54 mm on the Heft-Parker visual analog scale (HP VAS); moderate, 55-114 mm; and severe, greater than 114 mm. After IANB with 1.8 mL of 2% lidocaine, endodontic access preparation was initiated. Pain during treatment was recorded using the HP VAS. The primary outcome measure was the ability to undertake pulp access and canal instrumentation with no or mild pain. The success rates were statistically analyzed by multiple logistic regression test. There was a significant difference between the mild and severe preoperative pain group (P = .03). There was a positive correlation between the values of preoperative and intraoperative pain (r = .2 and .4 at 2 centers). The amount of preoperative pain can affect the anesthetic success rates of IANB in patients with symptomatic irreversible pulpitis.

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.

The Effect of 2 Injection Speeds on Local Anesthetic Discomfort During Inferior Alveolar Nerve Blocks

This randomized double-blind crossover trial investigated the discomfort associated with 2 injection speeds, low (60 seconds) and slow (100 seconds), during inferior alveolar nerve block by using 1.8 mL of 2% lidocaine with 1 : 100,000 epinephrine. Three phases were considered: (a) mucosa perforation, (b) needle insertion, and (c) solution injection. Thirty-two healthy adult volunteers needing bilateral inferior alveolar nerve blocks at least 1 week apart were enrolled in the present study. The anesthetic procedure discomfort was recorded by volunteers on a 10-cm visual analog scale in each phase for both injection speeds. Comparison between the 2 anesthesia speeds in each phase was performed by paired t test. Results showed no statistically significant difference between injection speeds regarding perforation (P = .1016), needle placement (P = .0584), or speed injection (P = .1806). The discomfort in all phases was considered low. We concluded that the 2 injection speeds tested did not affect the volunteers' pain perception during inferior alveolar nerve blocks.

Articaine and mepivacaine buccal infiltration in securing mandibular first molar pulp anesthesia following mepivacaine inferior alveolar nerve block: A randomized, double-blind crossover study

Aims:

A crossover double-blind, randomized study was designed to explore the efficacy of 2% mepivacaine with 1:100,000 adrenaline buccal infiltration and 4% articaine with 1:100,000 adrenaline buccal infiltration following 2% mepivacaine with 1:100,000 adrenaline inferior alveolar nerve block (IANB) for testing pulp anesthesia of mandibular first molar teeth in adult volunteers.

Materials and Methods:

A total of 23 healthy adult volunteers received two regimens with at least 1-week apart; one with 4% articaine buccal infiltration and 2% mepivacaine IANB (articaine regimen) and another with 2% mepivacaine buccal infiltration supplemented to 2% mepivacaine IANB (mepivacaine regimen). Pulp testing of first molar tooth was electronically measured twice at baseline, then at intervals of 2 min for the first 10 min, then every 5 min until 45 min postinjection. Anesthetic success was considered when two consecutive maximal stimulation on pulp testing readings without sensation were obtained within 10 min and continuously sustained for 45 min postinjection.

Results:

In total, the number of no sensations to maximum pulp testing for first molar teeth were significantly higher after articaine regimen than mepivacaine during 45 min postinjection (267 vs. 250 episodes, respectively, P < 0.001), however, both articaine and mepivacaine buccal infiltrations are equally effective in securing anesthetic success for first molar pulp anesthesia when supplemented to mepivacaine IANB injections (P > 0.05). Interestingly, volunteers in the articaine regimen provided faster onset and longer duration (means 2.78 min, 42.22 min, respectively) than mepivacaine regimen (means 4.26 min, 40.74 min, respectively) for first molar pulp anesthesia (P < 0.001).

Conclusions:

Supplementary mepivacaine and articaine buccal infiltrations produced similar successful first molar pulp anesthesia following mepivacaine IANB injections in volunteers. Articaine buccal infiltration produced faster onset and longer duration than mepivacaine buccal infiltration following mepivacaine IANB injections.

Alleviating Pain in Oculoplastic Procedures by Reducing the Rate of Injection of Local Anaesthetic

Purpose :

To investigate whether the rate of infiltration of local anaesthetic influences the pain or efficacy of local anaesthesia in oculoplastic surgery.

Methods :

A prospective observational study on consecutive patients undergoing a variety of oculoplastic procedures under local anaesthesia. An observer recorded the rate of injection of local anaesthetic during each procedure. The same mixture of local anaesthetic and the same needle gauge was used in all cases. Patients were asked to rate the pain of both the injection and the surgery using a visual analog scale (VAS).

Results :

77 consecutive patients were observed, 39/77 (50.6%) patients were female and the average age was 63.5 years (range 31-94). A statistically significant correlation was found between the rate of injection and the VAS score from the injection (p<0.0001, r=0.42). There was no significant correlation between the injection rate and the VAS score from the procedure itself (p=0.25, r=0.13). Additionally, a significant correlation was found between the injection VAS score and the procedure VAS score (p=0.0002, r=0.42).

Conclusion :

The slower the rate of injection of local anaesthetic, the less pain was reported by the patient from the injection itself. Indeed the perception of pain from the surgery overall was significantly related to the pain felt during the injection, highlighting the importance of minimising pain during the injection of the local anaesthetic. We conclude that slowing the rate of injection is an effective way of alleviating pain from administration of the anaesthetic.

The efficacy of an elevated concentration of lidocaine HCl in impacted lower third molar surgery

Background

There have been few studies on the effect of an elevated concentration of lidocaine hydrochloride in the surgical removal of an impacted lower third molar. This study aimed to examine the efficacy of 4% lidocaine along with 1:100,000 epinephrine compared to 2% lidocaine along with 1:100,000 epinephrine as inferior alveolar nerve block for the removal of an impacted lower third molar.

Methods

This single-blind study involved 31 healthy patients (mean age: 23 y; range: 19-33 y) with symmetrically impacted lower third molars as observed on panoramic radiographs. Volunteers required 2 surgical interventions by the same surgeon with a 3-week washout period. The volunteers were assigned either 4% lidocaine with 1:100,000 epinephrine or 2% lidocaine with 1:100,000 epinephrine as local anesthetic during each operation.

Results

We recorded the time of administration, need for additional anesthetic administration, total volume of anesthetic used. We found that the patient's preference for either of the 2 types of local anesthetic were significantly different (P < 0.05). However, the extent of pulpal anesthesia, surgical duration, and duration of soft tissue anesthesia were not significantly different.

Conclusions

Our study suggested that inferior alveolar nerve block using 4% lidocaine HCl with 1:100,000 epinephrine as a local anesthetic was clinically more effective than that using 2% lidocaine HCl with 1:100,000 epinephrine; the surgical duration was not affected, and no clinically adverse effects were encountered.

Does the combination of 3% mepivacaine plain plus 2% lidocaine with epinephrine improve anesthesia and reduce the pain of anesthetic injection for the inferior alveolar nerve block? A prospective, randomized, double-blind study

INTRODUCTION

In theory, using 3% mepivacaine initially for an inferior alveolar nerve (IAN) block would decrease the pain of injection, provide faster onset, and increase anesthetic success. The purpose of this prospective, randomized, double-blind study was to compare the degree of pulpal anesthesia obtained with a combination of 3% mepivacaine/2% lidocaine (1:100,000 epinephrine) versus a combination of 2% lidocaine (1:100,000 epinephrine)/2% lidocaine (1:100,000 epinephrine) in IAN blocks. Injection pain was also studied.

METHODS

One hundred asymptomatic subjects were randomly given a combination of a 1-cartridge volume of 3% mepivacaine plus a 1-cartridge volume of 2% lidocaine with 1:100,000 epinephrine and a combination of a 1-cartridge volume of 2% lidocaine with 1:100,000 epinephrine plus a 1-cartridge volume of 2% lidocaine with 1:100,000 epinephrine for the IAN block at 2 separate appointments. Subjects rated the pain of injection. The molars, premolars, and incisors were tested with an electric pulp tester in 4-minute cycles for 60 minutes. Anesthetic success was defined as the subject achieving 2 consecutive 80 readings within 15 minutes after completion of the IAN blocks and sustaining the 80 reading for 60 minutes.

RESULTS

Success was not significantly different (P > .05) between the 2 combinations. No statistical differences in injection pain or onset times were found.

CONCLUSIONS

The combination of 3% mepivacaine plus 2% lidocaine with 1:100,000 epinephrine was equivalent to the combination of 2 cartridges of 2% lidocaine with 1:100,000 epinephrine in terms of injection pain, onset time, and pulpal anesthetic success for the IAN block.

Efficacy of articaine versus lidocaine as a supplemental buccal infiltration in mandibular molars with irreversible pulpitis: a prospective, randomized, double-blind study

INTRODUCTION

Profound pulpal anesthesia in mandibular molars with irreversible pulpitis (IP) is often difficult to obtain and often requires supplemental injections after an ineffective inferior alveolar nerve block (IANB). The purpose of this prospective, randomized, double-blind study was to compare the efficacy of 4% articaine with 2% lidocaine for supplemental buccal infiltrations (BIs) after an ineffective IANB in mandibular molars with IP. In addition, the use of articaine for IANB and intraosseous injections was investigated.

METHODS

One hundred emergency patients diagnosed with IP of a mandibular molar were selected and received an IANB with 4% articaine. All injections were 1.7 mL with 1:100,000 epinephrine. All patients reported profound lip numbness after IANB. Patients with ineffective IANB (positive pulpal response to cold or pain on access) randomly received 4% articaine or 2% lidocaine as a supplemental BI. Endodontic access was initiated 5 minutes after deposition of the infiltration solution. Success was defined as no pain or no more than mild pain during endodontic access and instrumentation as measured on a visual analogue scale.

RESULTS

Seventy-four patients failed to achieve pulpal anesthesia after IANB with 4% articaine, resulting in IANB success rate of 26%. Success rates for supplemental BIs were 62% for articaine and 37% for lidocaine (P < .05). This effect was most pronounced in second molars (P < .05).

CONCLUSIONS

Supplemental BI with articaine was significantly more effective than lidocaine. The IANB success rate of 4% articaine confirmed published data.

Periodontal intraligament injection as alternative to inferior alveolar nerve block--meta-analysis of the literature from 1979 to 2012

OBJECTIVES

In a first meta-analysis, inferior alveolar nerve block (IANB) and periodontal intraligamentary injection anesthesia (ILA) were compared with focus on the failure rate of local anesthesia, pain during injection, additional injections, cardiovascular disturbances (CVD), and method-inherent differences (unwanted side effects, latency time, amount of anesthetic solution, duration of anesthesia) in adult patients.

MATERIALS AND METHODS

Prospective and retrospective studies with clinical comparison of both injection techniques considering the relevant outcome parameters in adult patients from 1979 to 2012 were included. A specific tool for assessing risk of bias in each included study was adopted. Data were assessed for methodological reliability and extracted and supplemented by sensitivity analysis by two independent reviewers.

RESULTS

Seven studies were included [evidence grade Ib (n=1), IIb (n=3), and III (n=3)]. For other parameter than CVD, the significant heterogeneity of the random effects did not allow the reporting of pooled summary effect estimates. CVD were found significantly more often after IANB [odds ratio (OR): 0.12 (0.02-0.69)]. Further analysis revealed less injection pain in cases of ILA [OR: 0.32 (0.1-1)]. For failure rates as well as for needed additional injections, no significant differences were detected. IANB showed a latency of >3 min, whereas ILA had nearly none. The effect of IANB is longer than for ILA.

CONCLUSIONS

Methodological and reporting flaws were consistently observed in the included articles. Except for CVD, it could not be shown that ILA is neither superior nor inferior compared to IANB.

CLINICAL RELEVANCE

IANB as "gold standard" for routine dental treatments should be discussed.

A prospective, randomized single-blind evaluation of effect of injection speed on anesthetic efficacy of inferior alveolar nerve block in patients with symptomatic irreversible pulpitis

INTRODUCTION

Speed of injection may affect the solution spread in the pterygomandibular space. It was hypothesized that speed of injection will affect the anesthetic efficacy of inferior alveolar nerve block (IANB) in patients with symptomatic irreversible pulpitis.

METHODS

Fifty-nine adult volunteers who were actively experiencing pain participated in this prospective, randomized, single-blind study. The patients were divided into 2 groups on a random basis and received either slow or rapid IANB with 3.6 mL of 2% lidocaine with 1:200,000 epinephrine. Endodontic access preparation was initiated after 15 minutes of the initial IANB. Pain during treatment was recorded by using the Heft-Parker visual analogue scale. The primary outcome measure, and the definition of success, was the ability to undertake pulp access and canal instrumentation with no or mild pain (Heft-Parker visual analog scale score < 55 mm). Secondary outcome measure was the solution deposition pain. Statistical analysis was performed by using Mann-Whitney U test and χ(2) test.

RESULTS

Slow and rapid injections gave 43% and 51% success rates, respectively. The difference was statistically insignificant. Slow injections produced less solution deposition pain than rapid injections.

CONCLUSIONS

Rate of injection has no effect on anesthetic success of IANB, but slow injections were more comfortable than rapid injections.

Effect of topical anesthesia on pain during infiltration injection and success of anesthesia for maxillary central incisors

INTRODUCTION

This study was performed to investigate the effect of topical anesthesia on pain during needle penetration and infiltration injection as well as the effect of pain during injection on success rate of anesthesia in maxillary central incisors.

METHODS

In a crossover double-blind study, 25 volunteers randomly received either topical anesthesia or placebo before infiltration injection with prilocaine for their maxillary central incisors in 2 separate appointments. The pain after needle penetration and during injection was separately recorded. An electric pulp tester was used to evaluate the success of the anesthetic injection. Data were analyzed by McNemar, Wilcoxon, and χ(2) tests.

RESULTS

Overall for 50 injections, 72% of the teeth had successful anesthesia. No significant difference was found between placebo and topical anesthetic groups for the pain of needle penetration as well as pain during injection (P > .05). The volunteers who reported moderate-to-severe pain during injection showed no significant difference in the success rate of anesthesia compared with those with no or mild pain during injections (P > .05).

CONCLUSIONS

Use of topical anesthesia had no significant effect on pain during either needle penetration or injection. Pain during injection had no significant effect on the success of anesthesia.