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: The aim of this study was 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 3.4 ml 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 for supplemental anaesthesia throughout treatment; the incidence of need for supplemental anaesthesia was also recorded. Data were statistically analysed using Mann-Whitney U- and Chi-squared (χ ) tests. Relative risk (RR) and 95% confidence interval (CI) of anaesthetic failure were calculated. The effect of pre-disposing 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 > .05). The IOP intensity during access cavity preparation and canal instrumentation was similar for both groups (p > .05). IOP intensity was associated with preoperative pain intensity and tooth type (p < .05). Overall anaesthetic success rate was 35.8% for mepivacaine and 41.2% for articaine (p > .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 > .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.