AimThis randomized, prospective, double‐blind, clinical trial assessed the effect of 1.3% and 5.25% sodium hypochlorite (NaOCl) as irrigants on post‐endodontic pain and medication intake following root canal treatment of mandibular molars with nonvital pulps.MethodologyThree hundred and eight patients, each with one symptomatic or asymptomatic molar, were randomly assigned, using the permuted‐block method, into two equal groups according to NaOCl concentration: 1.3% or 5.25% (n = 154). For both groups, syringe irrigation was performed using a 27‐gauge needle advanced into the canal to a depth of 3 mm from the working length; 3 mL were used between every two consecutive instruments. All root canal treatments were carried out in two visits, with no intracanal medication, by trained postgraduate students. The canals were prepared using the ProTaper Universal rotary system during the first visit. In the second visit 7 days later, the same irrigant per group was used and the canal walls were reprepared with the final instrument before filling the canal using the modified single‐cone technique with an epoxy resin‐based sealer. Patients assessed their postoperative pain using a 0–10 numerical rating scale immediately after instrumentation, 3, 24, 48 h and 7 days after the first visit and immediately following root canal filling. The incidence of rescue medication intake (Sham or analgesic) was also recorded; patients received a sham capsule to be used first, but, if pain persisted, an analgesic was prescribed. Outcome data were analysed using Mann–Whitney U‐test, Friedman's test, Wilcoxon's rank test and chi‐square (χ2) test. Relative risk reduction (RRR) and its 95% confidence interval (CI) were calculated for binary data.ResultsThe incidence and intensity of postoperative pain were significantly lower with 1.3% NaOCl than 5.25% NaOCl at all time‐points (P < 0.05). Postoperative pain intensity exceeded preoperative pain at 3 and 24 h with 5.25% NaOCl only (P < 0.05). The RRR in pain incidence was 38% (95% CI: 17%, 54%) immediately after instrumentation, 41% (95% CI: 31%, 49%) at 3 h, 42% (95% CI: 32%, 51%) at 24 h, 59% (95% CI: 45%, 69%) at 48 h, 62% (95% CI: 27%, 80%) at 7 days and 81% (95% CI: 68%, 89%) after root filling. RRR was 38% (95% CI: 1%, 61%) for sham intake and 69% (95% CI: 37%, 85%) for analgesic intake.ConclusionsUsing 1.3% NaOCl was associated with less intense and less frequent post‐endodontic pain than 5.25% NaOCl in mandibular molars with nonvital pulps treated in two visits. The incidence of pain was reduced by up to 60% within the week post‐instrumentation and 80% after root canal filling and the rescue analgesic intake by about 70% on using 1.3% NaOCl compared to 5.25% NaOCl.

Occlusal reduction reduced levels of postoperative pain in posterior mandibular teeth with symptomatic pulpitis and apical periodontitis only 12 h following both canal preparation and root filling.

Aim To assess the effect of Neem versus 2.5% NaOCl as root canal irrigants on the intensity of post‐operative pain and amount of endotoxins following root canal treatment of mandibular molars with necrotic pulps. Methodology This parallel, prospective, double‐blinded, randomized controlled trial with allocation ratio 1:1 was conducted in the out‐patient clinic of the Endodontic Department, Faculty of Dentistry, Cairo University, Egypt. Fifty healthy patients with mandibular molars with necrotic pulps were randomly assigned into two equal groups using computer software. In the intervention group, root canals were irrigated using Neem; whilst 2.5% NaOCl was used in the control group. A standard root canal treatment was performed in two visits using ProTaper Next rotary files, with no intracanal medication. Pain intensity was assessed using a numerical rating scale (NRS) 6, 12, 24 and 48 h following instrumentation and canal filling. Endotoxin samples were collected using three paper points before and after canal instrumentation and a sandwich ELISA method was used to quantify the level of endotoxins. Demographic, baseline, and outcome data were collected and analysed using chi‐square tests (for the comparisons of categorical variables), Mann–Whitney tests (for non‐normally distributed variables) and Student’s t tests (for normally distributed variables), A P‐value < 0.05 was considered to be statistically significant. Results The mean pain scores within the two groups decreased continually over time. The mean pain scores in the Neem group were lower than those in the 2.5% NaOCl group at 6, 12, 24 and 48 h following instrumentation and canal filling with no significant difference between them except at 24 h following instrumentation (P = 0.012). Both irrigants significantly reduced endotoxin levels compared to the pre‐instrumentation samples (P < 0.001) by 8% for the NaOCL group and 18% for the Neem group. Conclusion Neem and 2.5% NaOCl were not significantly different in terms of reducing the intensity of post‐operative pain during all follow‐up periods except at 24 h following instrumentation where Neem was associated with lower pain intensity. Both irrigants significantly reduced endotoxin levels but were not effective in eliminating endotoxins completely from root canals of mandibular molars with necrotic pulps.

AimThis randomized, prospective, controlled trial assessed the effect of occlusal reduction on post‐treatment endodontic pain and medication intake following root canal treatment of mandibular posterior teeth with symptomatic irreversible pulpitis with sensitivity to percussion treated in two visits.MethodologyThree hundred and eight patients were randomly assigned into two equal groups according to whether occlusal reduction was done or not (n = 154). For all patients, root canal treatment was carried out in two visits without intracanal medication. Patients assessed their pain using the 0–10 numerical rating scale (NRS) 6, 12, 24 and 48 h after the first visit (post‐instrumentation) and 6 and 12 h following root canal filling (post‐obturation). Patients, also, recorded their medication intake (sham or analgesic), post‐instrumentation and post‐obturation; patients initially received a sham capsule, but, if pain persisted, an analgesic was prescribed. Data were analysed using Mann–Whitney U‐test, Friedman’s test, Wilcoxon’s rank test and chi‐square (χ2) test. The relative risk (RR) and its 95% confidence interval (CI) were calculated for binary data.ResultsOcclusal reduction was associated with lower pain intensity than no occlusal reduction at 12 and 24 h post‐instrumentation (P < 0.05). Pain intensity significantly and gradually decreased with both groups at all post‐instrumentation and post‐obturation time‐points compared to preoperative pain (P < 0.05). The RR of moderate‐to‐severe pain was 0.61 (95% CI: 0.41, 0.91) 12 h post‐instrumentation, and the RR of pain incidence, regardless of its level, was 0.75 (95% CI: 0.61, 0.92) 24 h post‐instrumentation. There was no significant difference in medication intake (sham or analgesic) between groups (P > 0.05).ConclusionsOcclusal reduction was effective in reducing the intensity of postoperative pain 12 h and 24 h after root canal instrumentation in the first visit in patients with symptomatic irreversible pulpitis with sensitivity to percussion. Occlusal reduction lowered the risk of moderate‐to‐severe pain by about 40% 12 h post‐instrumentation and the overall risk of pain by 25% 24 h post‐instrumentation; yet, it did not affect medication intake.

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.