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 (χ2 ) 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.

Computed tomographic evaluation of canal shape instrumented by different kinematics rotary nickel-titanium systems.

INTRODUCTION: This study evaluated the effects of 2 different kinematics rotary nickel-titanium (NiTi) systems, Twisted File (TF), a continuous rotation full-sequence system, and WaveOne (WO), a reciprocating single-file system, on transportation, curvature, and volumetric changes of curved root canals by using cone-beam computed tomography. METHODS: Forty mesiobuccal canals of mandibular molars with angle of curvature ranging from 25°-35° were divided according to the NiTi rotary system used in canal preparation into 2 groups of 20 samples each, TF group and WO group. Canals were scanned by using an i-CAT cone-beam computed tomography scanner before and after instrumentation to evaluate canal transportation at coronal, middle, and apical thirds, canal curvature, and volumetric changes. The significance level was set at P ≤ .05. RESULTS: TF system recorded significantly lower mean of canal transportation than WO group at all canal thirds (apical P = .034, middle P = .003, and coronal P = .012). In both groups the apical third recorded the significantly least amount of transportation (P < .05). There was no significant difference between the 2 groups in canal curvature and volumetric changes after instrumentation (P > .05). CONCLUSIONS: Both TF and WO NiTi systems can be safely used to the full working length, resulting in satisfactory preservation of the original canal shape.