A Prospective, Randomized Single-blind Study of the Anesthetic Efficacy of Frequency-dependent Conduction Blockade of the Inferior Alveolar Nerve

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.

Postoperative endodontic pain of three different instrumentation techniques in asymptomatic necrotic mandibular molars with periapical lesion: a prospective, randomized, double-blind clinical trial

OBJECTIVES

The purpose of this prospective, randomized, double-blind study was to compare postoperative pain of root canal treatment in patients with asymptomatic mandibular molar teeth with necrotic pulp and periapical lesion using three different instrumentation techniques: hand, multi-file rotary (ProTaper Universal), and reciprocating single-file (Wave-One) instrumentation techniques.

MATERIALS AND METHODS

Ninety-six patients who fulfilled specific inclusion criteria were assigned to three groups according to the root canal instrumentation technique used: Hand (G1), ProTaper Universal (G2), and Wave-One (G3). One-visit root canal treatment was carried out, and the severity of the postoperative pain was assessed by the Heft-Parker visual analogue scale 6, 12, 18, 24, 48, and 72 h after treatment. Data were analyzed by Kruskal-Wallis, χ ², Cochrane Q, one-way ANOVA, and Spearman's correlation analyses (α = 0.05).

RESULTS

The patients in group 3 reported significantly lower postoperative pain levels at 6, 12, and 18 h compared with the patients in the two other groups (P < .05). In addition, the patients in group 2 reported significantly lower postoperative pain levels at 6 and 12 h compared with the patients in group 1 (P < .05). There were no significant differences in postoperative pain between the three groups at other time intervals (P > .05). The analgesic consumption was significantly higher in group 1 (P < .05), but no difference was seen between the two other groups (P > .05).

CLINICAL RELEVANCE

Postoperative pain was significantly lower in patients undergoing root canal instrumentation with the Wave-One file compared with the ProTaper Universal and hand files.

The success rate of bupivacaine and lidocaine as anesthetic agents in inferior alveolar nerve block in teeth with irreversible pulpitis without spontaneous pain

Objectives

Achieving adequate anesthesia with inferior alveolar nerve blocks (IANB) is of great importance during dental procedures. The aim of the present study was to assess the success rate of two anesthetic agents (bupivacaine and lidocaine) for IANB when treating teeth with irreversible pulpitis.

Materials and Methods

Sixty volunteer male and female patients who required root canal treatment of a mandibular molar due to caries participated in the present study. The inclusion criteria included prolonged pain to thermal stimulus but no spontaneous pain. The patients were randomly allocated to receive either 2% lidocaine with 1:80,000 epinephrine or 0.5% bupivacaine with 1:200,000 epinephrine as an IANB injection. The sensitivity of the teeth to a cold test as well as the amount of pain during access cavity preparation and root canal instrumentation were recorded. Results were statistically analyzed with the Chi-Square and Fischer's exact tests.

Results

At the final step, fifty-nine patients were included in the study. The success rate for bupivacaine and lidocaine groups were 20.0% and 24.1%, respectively. There was no significant difference between the two groups at any stage of the treatment procedure.

Conclusions

There was no difference in success rates of anesthesia when bupivacaine and lidocaine were used for IANB injections to treat mandibular molar teeth with irreversible pulpitis. Neither agent was able to completely anesthetize the teeth effectively. Therefore, practitioners should be prepared to administer supplemental anesthesia to overcome pain during root canal treatment.

Electrophysiological evidence on epileptiform activity enhanced by electrical stimulation of teeth in rats

The aim of this study was to evaluate the possible effects of electrical stimulation (ES) of tooth on penicillin-induced epileptiform activity in rats. Experiment was realized on 24 adult male Sprague Dawley rats. Rats were assigned three groups [stimulation group (SG), penicillin group (PG), and penicillin+stimulation group (PSG)]. In SG, ES was only applied. Ten pulses of electrical current were delivered to the teeth for a duration of 2 milliseconds at 1-second intervals from a stimulator. Currents were applied in the range of 40-240 μA with 40 μA steps. Electrocorticography (ECoG) recordings were taken before and after ES. In PG, ECoG recordings were taken before and during the injection of penicillin. In PSG, after epileptiform activity was induced, ES was applied and ECoG recordings were taken as in SG. All the data were analyzed with Student's t test. Applied currents did not cause any epileptiform activity in SG. When the PSG was compared with the PG it was seen that the spike frequency of epileptiform activity increased in a statistically significant way after application of 240 μA (P < 0·05). On the other hand current application caused an increase in the spike amplitude of the PSG compared with the amplitude of the PG, but it was not statistically significant. We concluded that ES of tooth with high current can trigger epileptiform activity in rats. For this reason, further research is required to evaluate the effects of ES of tooth for pulp testing on epileptic human subjects and antiepileptic drug users.

Effect of occlusal reduction on postoperative pain in teeth with irreversible pulpitis and mild tenderness to percussion

INTRODUCTION

Pain management after root canal treatment is a very important issue in clinical practice. The purpose of this study was to evaluate the effect of occlusal reduction on postoperative pain in teeth with irreversible pulpitis and tenderness to percussion.

METHODS

Fifty-four posterior vital teeth with sensitivity to percussion requiring endodontic treatment were included in this study. After administration of local anesthesia, the root canals were instrumented, and an intracanal calcium hydroxide dressing was placed. The patients were randomly divided into 2 groups of 27 each. In 1 group the occlusal surface was reduced (OR group), whereas in the other group the occlusal surface was not modified (no occlusal reduction, NOR group). Each patient was asked to record their postoperative pain on a visual analogue scale with 4 categories at 6 hours, 12 hours, 18 hours, 1 day, and then daily for 6 days after this treatment. Data were analyzed by t test, Cochran Q, χ(2), and Mann-Whitney tests.

RESULTS

Forty-six patients returned the visual analogue scale forms. There was no significant difference in postoperative pain between the 2 groups (P > .05) after root canal preparation and calcium hydroxide dressing.

CONCLUSIONS

Occlusal surface reduction did not provide any further reduction in postoperative pain for teeth with irreversible pulpitis and mild tenderness to percussion compared with no occlusal reduction.