Preoperative Factors Associated with Anesthesia Failure for Patients Undergoing Nonsurgical Root Canal Therapy: A National Dental Practice-Based Research Network Study

Effect of preemptive use of a nonsteroidal anti-inflammatory drug and a corticosteroid on the efficacy of inferior alveolar nerve blockade and postoperative pain control in endodontic treatment of molars with symptomatic pulpitis: A randomized double-blind placebo-controlled clinical trial

AIM

The anaesthetic success rate of an inferior alveolar nerve block (IANB) in mandibular molars with irreversible symptomatic pulpitis can be low, and postoperative pain control in teeth with this diagnosis can be challenging. This study aimed to evaluate the influence of preemptive use of dexamethasone and oral potassium diclofenac on the success of IANB. The influence of these drugs on the intensity of postoperative pain was assessed as a secondary outcome.

METHODOLOGY

Eighty-four patients with mandibular molars diagnosed with irreversible symptomatic pulpitis recorded preoperative pain intensity using a cold thermal test and a modified Numerical Rating Scale (mNRS). Sixty minutes before the anaesthetic procedure, patients were randomly assigned to one of three groups based on the medication they received: dexamethasone (4 mg), diclofenac potassium (50 mg), or placebo. All patients received IANB with 4% articaine (1:200 000 epinephrine), and 15 min later, they were evaluated for pain intensity using the cold thermal test. Anaesthetic success was analysed. The pain intensity was then recorded, and endodontic treatment and provisional restoration of the tooth were executed in a single session. Patients were monitored for 6, 12, 24, 48 and 72 h using the mNRS to assess the intensity of postoperative pain.

RESULTS

There was a statistically significant increase in anaesthetic success when 4 mg dexamethasone (39.3%) or 50 mg diclofenac potassium (21.4%) was used compared to the placebo group (3.6%) (p < .001), with no significant difference between the two drugs. Regarding postoperative pain, dexamethasone was superior to placebo at 6 h (p < .001), with diclofenac having an intermediate behaviour, not differing between dexamethasone and placebo (p > .05). There was no significant difference amongst the groups at 12 h (p > .05). At 24, 48 and 72 h, the effectiveness of dexamethasone and diclofenac were comparable, and both were superior to placebo (p < .001).

CONCLUSION

The use of dexamethasone or diclofenac potassium was favourable in terms of increasing the success rate of inferior alveolar nerve block in cases of mandibular molars with irreversible symptomatic pulpitis and decreased the occurrence of postoperative pain when compared to the use of a placebo.

Inferior Alveolar Nerve Block Success of 2% Mepivacaine versus 4% Articaine in Patients with Symptomatic Irreversible Pulpitis in Mandibular Molars: A Randomized Double-Blind Single-Centre Clinical Trial

AIM

To assess inferior alveolar nerve block (IANB) success of 2% mepivacaine (Scandonest 2%, Septodont, France) and 4% articaine (Septanest 4%, Septodont) in patients with symptomatic irreversible pulpitis (SIP) in mandibular molars during access cavity preparation and instrumentation.

METHODOLOGY

Three hundred and thirty patients with moderate-to-severe pain in mandibular molars with SIP randomly received either 3.6 mL 2% mepivacaine hydrochloride with 1:100 000 adrenalin or 3.4mL 4% articaine hydrochloride with 1:100 000 adrenalin (n=165). Intraoperative pain (IOP) intensity was assessed during access cavity preparation and canal instrumentation using 11-point numerical rating scale (NRS). Overall success was considered if the patient felt no-to-mild pain without the need of supplemental anaesthesia throughout treatment; the incidence of need for supplemental anaesthesia was also recorded. Data were statistically analyzed using Mann Whitney U and Chi² (χ² ) tests. Relative risk (RR) and 95% confidence interval (CI) of anaesthetic failure was calculated. The effect of predisposing factors on outcome variables was assessed using multivariable regression analyses. None of the participants reported any adverse effects.

RESULTS

Baseline variables were balanced between groups (p>0.05). The IOP intensity during access cavity preparation and canal instrumentation was similar for both groups (p>0.05). IOP intensity was associated with preoperative pain intensity and tooth type (p<0.05). Overall anaesthetic success rate was 35.8% for mepivacaine and 41.2% for articaine (p>0.05) with a relative risk of failure [95%CI] 1.09 [0.92, 1.30]. The need for supplemental anaesthesia occurred 43.6% and 38.2% with mepivacaine and articaine respectively (p>0.05; RR [95%CI]: 1.14 [0.88, 1.48]). Preoperative pain level and age were associated with the need for supplemental anaesthesia.

CONCLUSIONS

2% mepivacaine and 4% articaine demonstrate similar IANB success rates for mandibular molars with SIP. Intraoperative pain experience during endodontic treatment can be associated with preoperative pain, tooth type and age.

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.