Why Does Local Anaesthesia Not Work Every Time?

Articaine improves anesthetic achievement for exodontia performed by undergraduate dental students: A clinical comparative study

PURPOSE/OBJECTIVES

To assess the clinical performance of undergraduate dental students in delivering inferior alveolar nerve block (IANB) with either articaine or lidocaine, and to compare the success rate of their IANBs between articaine and lidocaine for the extraction of mandibular molar teeth.

METHODS

In this clinical trial, patients were randomly distributed into 2 study groups: articaine and lidocaine groups. In each group, dental students performed IANB followed by forceps extraction of 1 mandibular molar under close supervision. The operative parameters measured included: assessment of anesthetic technique (on 10 points visual analogue scale 'VAS-10'), onset and depth of anesthesia, intra-operative pain perceived by patients and their satisfaction level (on VAS-10), and the success rate of IANB (in terms of need to additional anesthesia). Data analyses used were descriptive statistics, t-test, χ² test, and Pearson's correlation.

RESULTS

One-hundred sixty patients were included in the final analysis, 80 in each group. The overall students' IANB technique was assessed as good (mean score 7.3). Articaine group showed significantly higher success rate of IANB (71%) compared to (55%) in lidocaine group, (P = 0.03). Patients also reported significantly higher satisfaction scores in the articaine group (P = 0.04). There were no significant difference in the onset of action and intra-operative pain level between the 2 groups.

CONCLUSIONS

Students' IANBs were generally assessed as "good." Articaine IANBs performed by undergraduate students showed significantly higher success rate than lidocaine IANBs. By using articaine, the anesthetic achievement was greater for mandibular molar extraction performed by undergraduate students.

Impact of maxillary teeth morphology on the failure rate of local anesthesia

Objective:

To investigate the effect of maxillary single and multiple rooted teeth on the success rate of buccal infiltration anesthesia.

Subjects and Methods:

This clinical study was performed by dividing the participants into three groups. Group one included 30 patients with upper anterior teeth, group two 23 patients with upper premolars teeth and group three 39 patients with upper molars for extraction. Onset time of anesthtic action was evaluted by using electronic pulp tester. Pulp testing assessments were carried out immediately before the injection and at the intervals of 2 mins following the injection until the anesthetic success obtains.

Results:

Seventy-nine patients in this study secured anesthetic success within study duration time (10 min). However, there were 13 patients with dental anesthesia failures (3 patients with single rooted teeth and 10 patients with multiple rooted teeth). There were no significant differences in the mean onset time of pulpal anesthesia between the anterior, middle and posterior teeth (P value = 0.449). Clinically, patients with single rooted teeth reported faster dental anesthesia and earlier teeth extraction than patients with multiple rooted teeth.

Conclusion:

This study showed that the single rooted teeth have faster pulpal anesthesia and early extraction than teeth with multiple roots but not statistically significant. Administration of extra local anesthetic cartridge or using intraseptal injection technique can be a solution to overcome the failure of anesthesia in the maxillary posterior teeth.

Pain Part 4: Odontogenic Pain

Pain is one of the major reasons that lead patients to seek dental care. For the majority of patients, the pain is of odontogenic origin, as a consequence of dental disease. The timely diagnosis and management of dental pain is an essential component of dental care, and this article reminds readers of the common presenting symptoms of simple dental pain, diagnoses and pragmatic management.

CLINICAL RELEVANCE

Pain of odontogenic origin is common, and distressing. However, the pathology is consistent, as are the symptoms, and an understanding of this underpins the careful history-taking that will lead the clinician to the diagnosis.

4% articaine buccal infiltration versus 2% lidocaine inferior alveolar nerve block for emergency root canal treatment in mandibular molars with irreversible pulpits: a randomized clinical study

AIM

To compare the anaesthetic efficacy of inferior alveolar nerve blocks (IANB) with 1.8 mL of 2% lidocaine (LI) to a buccal infiltration (BI) with 1.8 mL of 4% articaine (AR), both with 1 : 100 000 epinephrine, in patients with symptomatic irreversible pulpits in a randomized controlled trial.

METHODOLOGY

Volunteers presenting at the Emergency Centre (FOP-UNICAMP) were randomly divided into two groups (30 for AR and 20 for LI). Operator and patient were not blinded. Success was recorded when complete pain-free treatment was achieved after a single injection (IANB or BI) or when one supplemental injection was needed for emergency endodontic procedures. Success rate of supplemental injection was evaluated between and within groups using Fisher's exact test and chi-square test.

RESULTS

A higher success rate (P = 0.03/Fisher's exact test) was observed with AR (40%) than with LI (10%). No significant difference was found when a single injection plus one supplemental injection was compared between groups (P = 1.0; AR = 70%; LI = 80%). However, supplemental injection increased the anaesthetic success rates (AR, P = 0.04; LI, P = 0.0001) within groups.

CONCLUSIONS

Single anaesthesia techniques (IANB or BI) were not able to achieve pain-free emergency endodontic treatment. Supplemental anaesthetic techniques should be considered prior to treatment procedures in order to increase success rate (consort: registration number - NCT01912755/Fapesp: #2009/10834-4).

Pulpal anaesthesia for mandibular permanent first molar teeth: a double-blind randomized cross-over trial comparing buccal and buccal plus lingual infiltration injections in volunteers

AIM

To compare the efficacy of buccal and buccal plus lingual infiltration anaesthesia for permanent mandibular first molars.

METHODOLOGY

Thirty one healthy adult volunteers received each of the following methods of anaesthesia for a mandibular first molar tooth in a randomised order, 1) Buccal infiltration of 1.8 mL and needle penetration lingually. 2) Buccal infiltration of 0.9 mL, plus lingual infiltration of 0.9 mL. Two percent lidocaine with 1:100,000 epinephrine was used. Electrical pulp testing was performed before, and every 2 minutes for 30 minutes after injection. A successful outcome was recorded as the absence of pulp sensation on two or more consecutive maximal pulp tester stimulations (80 microA). Injection discomfort was assessed using visual analogue scales. Data were compared with McNemar and Wilcoxon Signed Ranks tests.

RESULTS

Buccal infiltration was successful in 38.7% of cases compared to 32.3% after combined infiltrations; the difference was not significant (P = 0.63). Buccal infiltration produced more episodes of no response to maximum stimulation than buccal and lingual infiltrations (129 and 114 respectively), this difference was not significant (P = 0.11). Peak anaesthetic effect occurred around 10-14 minutes after injection. There was no difference in injection discomfort between buccal injections of 0.9 mL and 1.8 mL of solution (P = 0.90). Lingual injection was more uncomfortable than lingual penetration (P = O.O02).

CONCLUSIONS

Buccal and buccal plus lingual infiltrations did not differ in their efficacy in producing anaesthesia of permanent first molar teeth.

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

This randomized double-blind crossover trial investigated the efficacy and discomfort associated with slow (60 seconds) and rapid (15 seconds) inferior alveolar nerve blocks (IANB) using 2.0 ml of 2% lidocaine with 1:80,000 epinephrine in securing mandibular first molar, premolar and lateral incisor pulp anesthesia in 38 healthy adult volunteers. Episodes of maximal stimulation (80 microA) without sensation on electronic pulp testing were recorded. Injection discomfort was self-recorded by volunteers on 100 mm visual analogue scales. Data were analyzed by McNemar, Friedman, Wilcoxon Signed Ranks, and paired t tests. Slow IANB produced more episodes of no response to maximal pulp stimulation than rapid IANB in molars (220 episodes versus 159, p < 0.001), premolars (253 episodes versus 216, p = 0.003) and lateral incisors (119 episodes versus 99, p = 0.049). Slow IANB was more comfortable than rapid IANB (p = 0.021).

A concise review of the basic biology and pharmacology of local analgesia

Local analgesics are the most commonly used group drugs in dental practice. However, due to their frequent use and high margin of safety, often dental practitioners neglect to properly understand the biology and pharmacology of these drugs. This article reviews the basic concepts of pain, pain pathways, the mode of action of local analgesics and factors which affect their usage. Specific details and properties of some currently available solutions are also outlined. A greater understanding of the biology and pharmacology of local anaesthetics will ultimately lead to safer and more effective use in everyday clinical practice.