Influence of Injection Speed on the Effectiveness of Incisive/Mental Nerve Block: A Randomized, Controlled, Double-blind Study in Adult Volunteers

Articaine Infiltrations of the Mandibular Lateral Incisor-Is It Volume or Location of the Infiltrations That Affect Success? A Prospective, Randomized Crossover Study

INTRODUCTION

A combination labial infiltration (1.8 mL) plus lingual infiltration (1.8 mL) of 4% articaine with 1:100,000 epinephrine in the mandibular lateral incisor was found superior to a labial infiltration of 1.8 mL of the same solution. However, it is not known whether the volume or the location had the greatest effect. Therefore, the purpose of this prospective, randomized crossover study was to determine the anesthetic efficacy of a labial infiltration of a 3.6 mL volume of 4% articaine with 1:100,000 epinephrine compared with labial infiltration (1.8 mL) plus lingual infiltration (1.8 mL) of 4% articaine with 1:100,000 epinephrine in the mandibular lateral incisor.

METHODS

One hundred subjects randomly received 2 sets of injections, using 4% articaine with 1:100,000 epinephrine, consisting of labial and lingual infiltrations of 1.8 mL (3.6 mL total) and 2 labial infiltrations of 1.8 mL (3.6 mL total) of the mandibular lateral incisor in 2 separate appointments. Electric pulp testing was used to determine anesthetic success (highest 80/80 reading). The data were analyzed statistically.

RESULTS

The labial and lingual combination exhibited a significantly higher anesthetic success rate (97%) when compared with the 2 labial infiltrations (74%) and had significantly higher 80/80s readings from 1 minute to 58 minutes.

CONCLUSIONS

Within the limitations of this clinical study, a combination labial plus lingual infiltration using a 3.6-mL volume of 4% articaine with 1:100,000 epinephrine significantly increased pulpal anesthetic success for the mandibular lateral incisor when compared with a labial infiltration using a 3.6-mL volume of articaine. Therefore, location of the infiltrations was more important than volume.

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-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.

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.

Interventions for increasing acceptance of local anaesthetic in children and adolescents having dental treatment

BACKGROUND

Delivery of pain-free dentistry is crucial for reducing fear and anxiety, completion of treatment, and increasing acceptance of future dental treatment in children. Local anaesthetic (LA) facilitates this pain-free approach but it remains challenging. A number of interventions to help children cope with delivery of LA have been described, with no consensus on the best method to increase its acceptance.

OBJECTIVES

To evaluate the effects of methods for acceptance of LA in children and adolescents during dental treatment.

SEARCH METHODS

Cochrane Oral Health's Information Specialist searched the Cochrane Oral Health's Trials Register (to 24 May 2019); the Cochrane Central Register of Controlled Trials (CENTRAL; 2019 Issue 4) in the Cochrane Library (searched 24 May 2019); MEDLINE Ovid (1946 to 24 of May 2019); Embase Ovid (1980 to 24 May 2019); and Web of Science (1900 to 24 May 2019). The US National Institutes of Health Ongoing Trials Register (ClinicalTrials.gov) and World Health Organization International Clinical Trials Registry Platform were also searched to 24 May 2019. There were no restrictions on language or date of publications.

SELECTION CRITERIA

Parallel randomised controlled trials (RCTs) of interventions used to increase acceptance of dental LA in children and adolescents under the age of 18 years.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. We performed data extraction and assessment of risk of bias independently and in duplicate. We contacted authors for missing information. We assessed the certainty of the body of evidence using GRADE.

MAIN RESULTS

We included 26 trials with 2435 randomised participants aged between 2 and 16 years. Studies were carried out between 2002 and 2019 in dental clinics in the UK, USA, the Netherlands, Iran, India, France, Egypt, Saudi Arabia, Syria, Mexico, and Korea. Studies included equipment interventions (using several LA delivery devices for injection or audiovisual aids used immediately prior to or during LA delivery or both) and dentist interventions (psychological behaviour interventions delivered in advance of LA (video modelling), or immediately prior to or during delivery of LA or both (hypnosis, counter-stimulation). We judged one study to be at low risk and the rest at high risk of bias. Clinical heterogeneity of the included studies rendered it impossible to pool data into meta-analyses. None of the studies reported on our primary outcome of acceptance of LA. No studies reported on the following secondary outcomes: completion of dental treatment, successful LA/painless treatment, patient satisfaction, parent satisfaction, and adverse events. Audiovisual distraction compared to conventional treatment: the evidence was uncertain for the outcome pain-related behaviour during delivery of LA with a reduction in negative behaviour when 3D video glasses where used in the audiovisual distraction group (risk ratio (RR) 0.13, 95% confidence interval (CI) 0.03 to 0.50; 1 trial, 60 participants; very low-certainty evidence). The wand versus conventional treatment: the evidence was uncertain regarding the effect of the wand on pain-related behaviour during delivery of LA. Four studies reported a benefit in using the wand while the remaining studies results suggested no difference between the two methods of delivering LA (six trials, 704 participants; very low-certainty evidence). Counter-stimulation/distraction versus conventional treatment: the evidence was uncertain for the outcome pain experience during delivery of LA with children experiencing less pain when counter-stimulation was used (RR 0.12, 95% CI 0.04 to 0.34; 1 trial, 134 participants; very low-certainty evidence). Hypnosis versus conventional treatment: the evidence was uncertain for the outcome pain experience during delivery of LA with participants in the hypnosis group experiencing less pain (mean difference (MD) -1.79, 95% CI -3.01 to -0.57; 1 trial, 29 participants; very low-certainty evidence). Other comparisons considered included pre-cooling of the injection site, the wand versus Sleeper One, the use of a camouflage syringe, use of an electrical counter-stimulation device, and video modelling acclimatisation, and had a single study each. The findings from these other comparisons were insufficient to draw any affirmative conclusions about their effectiveness, and were considered to be very low-certainty evidence.

AUTHORS' CONCLUSIONS

We did not find sufficient evidence to draw firm conclusions as to the best interventions to increase acceptance of LA in children due to variation in methodology and nature/timing of outcome measures. We recommend further parallel RCTs, reported in line with the CONSORT Statement. Care should be taken when choosing outcome measures.

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.

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.

Effect of massage on the efficacy of the mental and incisive nerve block

The purpose of this trial was to assess the effect of soft tissue massage on the efficacy of the mental and incisive nerve block (MINB). Thirty-eight volunteers received MINB of 2.2 mL of 2% lidocaine with 1 : 80,000 epinephrine on 2 occasions. At one visit the soft tissue overlying the injection site was massaged for 60 seconds (active treatment). At the other visit the crowns of the mandibular premolar teeth were massaged (control treatment). Order of treatments was randomized. An electronic pulp tester was used to measure pulpal anesthesia in the ipsilateral mandibular first molar, a premolar, and lateral incisor teeth up to 45 minutes following the injection. The efficacy of pulp anesthesia was determined by 2 methods: (a) by quantifying the number of episodes with no response to maximal electronic pulp stimulation after each treatment, and (b) by quantifying the number of volunteers with no response to maximal pulp stimulation (80 reading) on 2 or more consecutive tests, termed anesthetic success. Data were analyzed by McNemar, Mann-Whitney, and paired-samples t tests. Anesthetic success was 52.6% for active and 42.1% for control treatment for lateral incisors, 89.5 and 86.8% respectively for premolars, and 50.0 and 42.1% respectively for first molars (P = .344, 1.0, and .508 respectively). There were no significant differences in the number of episodes of negative response to maximum pulp tester stimulation between active and control massage. A total of 131 episodes were recorded after both active and control massage in lateral incisors (McNemar test, P = 1.0), 329 (active) versus 316 (control) episodes in the premolars (McNemar test, P = .344), and 119 (active) versus 109 (control) episodes respectively for first molars (McNemar test, P = .444). Speed of anesthetic onset and discomfort did not differ between treatments. We concluded that soft tissue massage after MINB does not influence anesthetic efficacy.

Decreasing the pain of finger block injection: level II evidence

BACKGROUND

There is level II evidence that volunteers prefer the single subcutaneous injection in the midline of the proximal phalanx with lidocaine and epinephrine (SIMPLE) finger block over the classic two dorsal injection block technique. The purpose of this study was to possibly further decrease the pain of digital block injection by examining the effect of the duration of injection on the pain felt by volunteers receiving the SIMPLE block at two different injection rates.

METHODS

Forty healthy blinded volunteers were injected 2 mL of lidocaine 1 % and epinephrine 1/100,000 in the digital palmar crease of both long fingers, one at a time. Two different rates of injection were used: 8 and 60 s. Pain scores were measured using a visual analogue scale and the volunteers were asked which of injection techniques they preferred.

RESULTS

The visual analogue scale results revealed less pain with the slow injection (p < 0.001). Thirty three out of 40 volunteers preferred the slow injection rate. No difference could be attributed to sex of participants or to the first hand injected.

CONCLUSION

Blinded volunteers preferred digital blocks injected over 60 s to the more rapid 8 s. Decreasing the pain of injection only takes a minute of our valuable time for finger blocks.

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.

Reducing the pain of local 1% lidocaine infiltration with a preceding bacteriostatic saline injection: a double-blind prospective trial

BACKGROUND

Lidocaine injection for local anesthesia is a common podiatric medical procedure. We tested the hypothesis that injection of bacteriostatic saline solution containing 0.9% benzyl alcohol before the lidocaine infiltration can reduce the burning caused by lidocaine injection.

METHODS

This double-blind prospective trial involved 45 participants who each received four injections in two areas of the dorsum of the foot and rated the perceived pain on a visual analog scale. The order of the injections was designed to disguise the control and intervention arms of the study.

RESULTS

The sensation of the lidocaine injection after the injection of saline was reduced significantly (P = .028). The percentage of lidocaine injections with visual analog scale scores of 0 increased by 36% after preinjection with bacteriostatic saline solution containing 0.9% benzyl alcohol.

CONCLUSIONS

The fact that 40% of the intervention visual analog scale pain scores for lidocaine injections were 0 suggests that a near painless lidocaine injection technique is an achievable goal and that the present technique is a simple and inexpensive method of reducing the pain of lidocaine injections.

The efficacy of infiltration anaesthesia for adult mandibular incisors: a randomised double-blind cross-over trial comparing articaine and lidocaine buccal and buccal plus lingual infiltrations

AIM

To compare the efficacy of 2% lidocaine and 4% articaine both with 1:100,000 adrenaline in anaesthetising the pulps of mandibular incisors.

METHODS

Thirty-one healthy adult volunteers received the following local anaesthetic regimens adjacent to a mandibular central incisor: 1) buccal infiltration of 1.8 mL lidocaine plus dummy lingual injection (LB), 2) buccal plus lingual infiltrations of 0.9 mL lidocaine (LBL), 3) buccal infiltration of 1.8 mL articaine plus dummy lingual injection (AB), 4) buccal plus lingual infiltrations of 0.9 mL articaine (ABL). Pulp sensitivities of the central incisor and contralateral lateral incisor were assessed electronically. Anaesthetic efficacy was determined by two methods: 1) Recording the number of episodes with no responses to maximal electronic pulp tester stimulation during the course of the study period, 2) recording the number of volunteers with no response to maximal pulp tester stimulation within 15 min and maintained for 45 min (defined as sustained anaesthesia). Data were analysed by McNemar, chi-square, Mann-Whitney and paired t-tests.

RESULTS

For both test teeth, the number of episodes of no sensation on maximal stimulation was significantly greater after articaine than lidocaine for both techniques. The split buccal plus lingual dose was more effective than the buccal injection alone for both solutions (p <0.001). 4% articaine was more effective than 2% lidocaine when comparing sustained anaesthesia in both teeth for each technique (p <0.001), however, there was no difference in sustained anaesthesia between techniques for either tooth or solution.

CONCLUSIONS

4% articaine was more effective than 2% lidocaine (both with 1:100,000 adrenaline) in anaesthetising the pulps of lower incisor teeth after buccal or buccal plus lingual infiltrations.

Anesthetic efficacy of articaine and lidocaine for incisive/mental nerve block

INTRODUCTION

The incisive/mental nerve block (IMNB) could be an alternative to the inferior alveolar nerve block in the mandibular anterior teeth. The effectiveness of articaine has not been tested in IMNB.

METHODS

This prospective randomized double-blind crossover study compared the anesthetic efficacy of 0.6 mL 4% articaine and 2% lidocaine, both with 1:100.000 epinephrine administered as IMNB to 40 volunteers in two sessions. Pulpal anesthesia of lateral incisor through premolars was tested with an electric pulp tester. The injection and postoperative pain were evaluated by using visual analog scales. The onset (time from the end of injection to the absence of pulpal response) and duration of pulpal anesthesia (time recorded before two positive responses to the pulp tester) and the anesthesia success (two consecutive readings of 80 without response and onset<or=10 minutes) were measured.

RESULTS

Articaine provided a higher success rate (p<0.001) of anesthesia than lidocaine for the lateral incisor (32.5%), the canine (55%), and the first (72.5%) and second (80%) premolars and a faster onset (p<0.05) for canine and increased duration (p<0.05) of anesthesia for premolars. The median duration of premolars anesthesia was 10 and 20 minutes, respectively, with lidocaine and articaine. There were no differences in pain scores between the solutions (p>0.05).

CONCLUSIONS

Articaine promoted higher anesthesia success and longer duration of anesthesia than lidocaine for most of the teeth after IMNB although anesthesia success could be considered clinically appropriated only for premolars. The volume of local anesthetic used in the present study may not be appropriate for procedures lasting longer than 10 minutes.