Background/Objectives: Pain after root canal treatment is a common concern that can greatly affect a patient’s quality of life. Identifying the factors contributing to this pain and focusing on those supported by high-quality research can lead to more effective pain management. This narrative review aims to analyze all available systematic reviews on this topic to determine what has been proven to help decrease pain following the root canal procedure. Methods: A comprehensive literature search was conducted across Scopus and Google Scholar from January 2000 to January 2024, using defined MeSH terms. This yielded 51 systematic reviews, of which 45 specifically investigated factors reducing postoperative pain related to root canal treatment. Results: Eleven factors were identified in the literature, with only eight factors supported by low- to moderate-quality evidence to reduce postoperative pain related to root canal treatment. These eight factors include (1) laser therapy, (2) nonsteroidal anti-inflammatory drugs (especially when combined with acetaminophen) and corticosteroids, (3) ultrasonic irrigation and low concentrations of sodium hypochlorite, (4) cryotherapy, (5) specific combinations of intracanal medicaments (notably calcium hydroxide with chlorhexidine), (6) bioceramic sealers, (7) rotary instrumentation, and (8) apical patency. Conclusions: The insights gained from this narrative review highlight several important factors that reduce postoperative pain related to root canal treatment. Nevertheless, the observed variability in the quality of the evidence calls attention to the necessity for further high-quality research.

<h4>Introduction</h4>This study systematically reviewed literature regarding the effect of different concentrations of sodium hypochlorite (NaOCl) used during root canal treatment (RCT) on postendodontic pain (PEP) and rescue analgesia.<h4>Methods</h4>Following registration with PROSPERO (CRD42023388916), a search was conducted using PubMed, Scopus, Web of Science, and Embase databases. Randomized controlled trials of patients receiving RCT which assessed PEP at different time intervals were included. Following data extraction and Cochrane risk of bias assessment 2, meta-analyses were performed to evaluate PEP during the first 48 hours along with rescue analgesic intake. The certainty of the evidence was evaluated using the Grading of Recommendations, Assessment, Development, and Evaluation approach.<h4>Results</h4>Five randomized controlled trials with 674 patients were included. One study exhibited a low risk of bias, while 4 raised some concerns. Patients treated with low concentrations of NaOCl (≤3%) were significantly less likely to report PEP at 24 hours (OR = 2.32; [95% CI, 1.63-3.31]; P < .05) and 48 hours (OR = 2.49; [95% CI, 1.73-3.59]; P < .05) as compared with high concentrations of NaOCl (≥5%). Furthermore, with low concentrations of NaOCl, significantly lesser moderate-severe PEP was reported at 24 hours (OR = 2.32; [95% CI, 1.47-3.62]; P < .05) and 48 hours (OR = 2.35; [95% CI, 1.32-4.16]; P < .05) and lesser analgesia was needed (OR = 2.43; [95% CI, 1.48-4.00]; P < .05).<h4>Conclusions</h4>While PEP can be influenced by several factors, low certainty evidence suggests that when NaOCl is used as an irrigant during RCT, PEP may be less likely with lower concentrations of NaOCl. Moderate certainty evidence indicates that lesser analgesia may be required with lower concentrations of NaOCl. These results should be cautiously interpreted.

This systematic review and meta-analysis aimed to determine whether apical patency increases postoperative pain after endodontic therapy. This study explored the degree and incidence of postoperative pain during root canal therapy, as well as the number of required analgesic doses. We searched PubMed, Scopus, Embase, Web of Science, Cochrane Library, and gray literature from the date of database inception until May 2023. RevMan 5.4 software was used for data analysis. Twelve studies were considered eligible for meta-analysis. The mean pain scores on days 1 (mean difference [MD] = -1.69) and 2 (MD = -0.85) differed significantly between the apical patency and non-patency groups. The odds for pain after 24 h were significantly lower (OR 0.59) in the apical patency group than in the non-patency group. Furthermore, the mean number of required analgesic doses was not significantly different between the two groups. In conclusion, apical patency significantly alleviated postoperative pain (low-quality evidence) and reduced the incidence of pain (moderate evidence). However, high-quality randomized controlled trials are required to validate these findings.

<h4>Objective</h4>To evaluate the comparative effect of irrigation activation systems on postoperative pain after single-visit nonsurgical root canal treatment using a systematic review and network meta-analysis.<h4>Methods</h4>A systematic search of PubMed/MEDLINE, Embase, Cochrane CENTRAL, and clinical trial registries was conducted in accordance with PRISMA-NMA recommendations. Randomized and quasi-randomized clinical trials evaluating postoperative pain after single-visit root canal treatment with different irrigation activation protocols were considered eligible. The primary outcome was 24-h postoperative pain intensity. Secondary outcomes included pain at other postoperative time points, analgesic intake, flare-up incidence, and categorical pain severity. Risk of bias was assessed using RoB 2 and ROBINS-I, and certainty of evidence was assessed using the GRADE framework. A frequentist random-effects network meta-analysis was performed using standardized mean differences.<h4>Results</h4>Seven studies with extractable continuous 24-h postoperative pain data contributed to the primary network meta-analysis. Compared with conventional irrigation, laser-activated irrigation showed the largest reduction in 24-h postoperative pain (SMD = -1.21; 95% CI: -1.86 to -0.55; P-score = 0.993), followed by passive ultrasonic irrigation (SMD = -0.39; 95% CI: -0.86 to 0.08; P-score = 0.520) and sonic activation (SMD = -0.32; 95% CI: -0.85 to 0.22; P-score = 0.429). Conventional irrigation had the lowest P-score (0.058). The certainty of evidence ranged from low to moderate, with downgrading mainly due to imprecision, clinical heterogeneity, and limited direct evidence for some comparisons. Risk-of-bias assessment identified predominantly low-risk randomized trials, although some studies raised concerns related to deviations from intended interventions, incomplete blinding, or incomplete outcome reporting.<h4>Conclusions</h4>Laser-activated irrigation may reduce 24-h postoperative pain compared with conventional irrigation after single-visit root canal treatment. The effects of passive ultrasonic irrigation and sonic activation were less certain. Treatment rankings should be interpreted alongside effect estimates, confidence intervals, risk of bias, clinical heterogeneity, and certainty of evidence rather than as independent evidence of clinical superiority.<h4>Clinical significance</h4>Irrigation activation may influence early postoperative pain after single-visit root canal treatment. Current evidence suggests a potential short-term pain-reduction benefit with laser-activated irrigation, but the certainty of evidence remains limited. Clinicians should interpret treatment hierarchy cautiously and consider feasibility, cost, case complexity, and patient-related factors when selecting irrigation activation protocols.

Abstract Background: There are many research studies directing in lowering postoperative pain in root canal therapy. The use of intracanal cryotherapy in root canal treatment is recently introduced, and many researchers are inclined towards this techniques. This systematic review will give an insight into its application in endodontic therapy and its effects on postoperative pain.The aim of this systematic review is to evaluate the effect of intracanal cryotherapy on the postoperative pain in patients with pulp diseases and with or without peri-radicular infection during root canal therapy. This systematic review will include randomized controlled trials only. The studies should encompass patients with pulpal diseases, i.e. irreversible pulpitis and pulp necrosis in teeth. Previously root treated teeth, immature, and teeth with root resorption will not be included. Methods: We will conduct a comprehensive search strategy using electronic databases PubMed, EMBASE (Ovid), Scopus, and Cochrane library. A predefined inclusion and exclusion criteria will be utilized for the selection of studies. The reference list of selected studies will be manually searched. We will extract data from studies on a structured data collection form. At the same time, the risk of bias assessment of studies using the Cochrane risk of bias assessment tools will be performed by two reviewers independently. Furthermore, qualitative and quantitative data synthesis will be accomplished. The data will be presented in the form of table of summary of findings. Discussion: This systematic review will assess the role of intracanal cryotherapy in the form of cold saline irrigation as a final irrigant during root canal therapy. The quality of evidence will ranked as high, moderate low or very low using GRADE approach. Comprehensive search strategy, risk of bias assessment using Cochrane risk of bias assessment tool by two reviewers are the strength of this systematic review. Systematic review registration number: The protocol is registered with the International Prospective Register of Systematic Reviews. (PROSPERO CRD 42020163438)

<b>Background/Objectives</b>: This study aimed to evaluate the effect of intracanal cryotherapy on postoperative pain across obturation materials with different chemical compositions and physical properties in single-visit root canal treatment. <b>Methods</b>: Patients diagnosed with irreversible pulpitis (<i>n</i> = 73), treated in a single visit by the same operator, were categorized based on the obturation material used (AH Plus, TotalFill BC Sealer, and TotalFill BC RRM) and whether intracanal cryotherapy (20 mL of sterile saline at 4 °C for 5 min) was applied. Visual Analog Scale (VAS) scores obtained from patient follow-up forms at 24, 48, and 72 h were evaluated. <b>Results</b>: Cryotherapy (+) groups showed consistently lower pain scores at all time points compared with cryotherapy (-) groups (<i>p</i> < 0.001). Within the cryotherapy (+) groups, both TotalFill BC Sealer and TotalFill BC RRM exhibited significantly lower pain scores than AH Plus at 48 h (<i>p</i> < 0.05). In the cryotherapy (-) groups, TotalFill BC Sealer showed significantly lower pain scores on the third postoperative day (<i>p</i> < 0.05). <b>Conclusions</b>: Intracanal cryotherapy may serve as an effective adjunctive technique associated with lower early postoperative pain scores. Material-related differences became evident at 48 and 72 h, suggesting that obturation material selection may influence postoperative pain patterns and patient comfort during the later postoperative period.