Predictors, prevention, and management of postoperative pain associated with nonsurgical root canal treatment: A systematic review

Effect of intracanal cryotherapy on post-operative pain in single-visit endodontic retreatment: a randomized clinical trial

BACKGROUND

This randomized clinical trial aimed to evaluate the effect of intracanal cryotherapy with 2-4 °C normal saline irrigation on post-operative pain after single-visit non-surgical root canal retreatment.

METHODS

Forty-six single-rooted, single-canal teeth requiring non-surgical root canal retreatment were randomly assigned to two groups (n = 23): a cryotherapy group and a control group. All the treatments were completed during a single visit. A combination of nickel-titanium and stainless-steel files was used for the removal of gutta-percha and root canal preparation, and irrigation was performed using 5.25% NaOCl and 17% EDTA. The cryotherapy group had a final irrigation temperature of 2-4 °C for 5 min before root canal obturation, whereas the control group received irrigation at room temperature. Post-operative pain levels were assessed via the Numerical Rating Scale at 6, 18, 24, 48, 72, and 168 h (up to 7 days). The number of analgesics consumed at the same intervals was also recorded. Statistical analysis was performed using the Chi-Square test, Mann-Whitney test, and Independent Samples test, with the significance level set at 0.05.

RESULTS

There was a statistically significant difference in post-operative pain between the cryotherapy group and the control group at 6 h after treatment (P < 0.05). However, post-operative pain levels were not significantly different at 18, 24, 48, 72, or 168 h after treatment (P > 0.05). Additionally, there was no statistically significant difference between the groups in terms of analgesic intake (P > 0.05).

CONCLUSION

Intracanal cryotherapy can effectively reduce short-term post-operative pain, but it has no effect on long-term pain or the need for analgesics.

Spontaneous and Masticatory Post-endodontic Pain After Using Endomethasone N vs SP Root Canal Sealers: A Randomised Controlled Clinical Trial

OBJECTIVE

Post-endodontic pain (PEP) after endodontic treatment (ET) might be reduced by adding cortisone to the composition of root canal sealer (RCS). This study aimed to test this hypothesis using grade A methodology.

METHODS

A multicentric prospective randomised controlled clinical trial was performed in general practice. Adult patients with an indication of ET in a molar or premolar performed in one session were included be-tween 2021 and 2022 in 15 centres. The main objective was to demonstrate the superiority of Endomethasone N RCS (EndoN), compared to its hydrocortisone-free equivalent Endomethasone SP RCS (EndoSP), regarding the reduction of the maximum spontaneous PEP pain during the 7 days following the ET, self-estimated on a 0���100 mm Visual Analogic Scale (VAS). The secondary objectives were to assess 1) spontaneous PEP, 2) pro-voked (masticatory) PEP, 3) intake of analgesics, 4) quality of life and anxiety before and after ET, and 5) safety.

RESULTS

The final sample consisted of 286 patients with a mean age of 47.7 years, including 51% men and 49% women. Before ET, 49.7% of the teeth were asymptomatic; provoked pain occurred in 29.4% and sponta-neous pain in 21.0%. The study evidenced a lower maximum spontaneous PEP intensity during the 7 days fol-lowing ET in EndoN compared to the EndoSP group (13.5+-17.9 vs 23.9+-26.6, IC 95% 10.5 [5.2���15.8], p=0.0001 Wilcoxon test). Maximal masticatory PEP was also lower in the EndoN group (12.3+-19.1 vs 24.0+-27.8, IC 95% 11.7 [5.8���17.6], p<0.0001 Wilcoxon test). At every evaluation time, the masticatory PEP in the EndoSP group was higher than in the EndoN group. In addition, no serious adverse events occurred during the study.

CONCLUSION

This RCT demonstrated EndoN's superiority over EndoSP in reducing spontaneous and mastica-tory PEP during the 7 days following ET. This study was funded by the Septodont company (Saint Maur des Foss��s, France) and registered at ClinicalTrials.gov # NCT04885686.

Efficacy of preoperative and postoperative medications in reducing pain after non-surgical root canal treatment: an umbrella review

OBJECTIVE

This study analyzed, using an umbrella review, existing systematic reviews on medications to prevent and control postoperative endodontic pain to guide professionals in choosing the most effective drug.

MATERIALS AND METHODS

An electronic search in the PubMed (MEDLINE), LILACS, SciELO, EMBASE, Scopus, Web of Science, Cochrane Reviews, and Data Archiving and Networked Services (DANS) databases retrieved 17 systematic reviews. The study included only systematic reviews of clinical trials with or without meta-analyses evaluating effectiveness of medications in reducing pain after non-surgical endodontic treatment.

RESULTS

The evidence showed that steroidal and non-steroidal anti-inflammatory drugs and opioids effectively controlled pain within six to 24 h.

CONCLUSIONS

Dexamethasone, prednisolone, paracetamol, and mainly ibuprofen provided higher postoperative pain relief. The quality of evidence of the reviews ranged from very low to high, and the risk of bias from low to high, suggesting the need for well-designed clinical trials to provide confirmatory evidence.

CLINICAL RELEVANCE

This review emphasizes the efficacy of developing protocols for pain control after endodontic therapy.

Postoperative pain in oncological patients subjected to nonsurgical root canal treatment: a prospective case-control study

OBJECTIVES

The purpose of this prospective study was to evaluate the incidence and intensity of postoperative pain in oncological patients with infected teeth subjected to nonsurgical root canal treatment or retreatment.

METHODS

Teeth with apical periodontitis from healthy control patients and oncological patients (n = 70 per group) were root canal treated/retreated and evaluated for the development of postoperative pain. Patients from the two groups were matched for tooth type, gender, clinical manifestation of apical periodontitis, and intervention type. A visual analogue scale (VSA) was used to evaluate the incidence of postoperative pain at 24 h, 72 h, 7d, and 15d after chemomechanical procedures. Data were statistically analyzed for the incidence and intensity of postoperative pain in the two groups.

RESULTS

Preoperative pain occurred in 10% of the individuals and in all these cases pain showed a reduction in intensity or was absent after endodontic intervention at 24-h evaluation. The overall incidence of postoperative pain at 24 h was 14% in oncology patients and 30% in controls (p = 0.03). At 72 h, the respective corresponding figures were 4% and 8.5% (p > 0.05). At 7 and 15 days, all patients were asymptomatic, irrespective of the group.

CONCLUSIONS

No significant differences in postoperative pain were found between control and oncological patients. The low incidence of postoperative pain observed in both groups supports the routine use of nonsurgical root canal treatment/retreatment as valid options in oncological patients.

CLINICAL RELEVANCE

Oncological patients had no increased risk of postoperative pain in comparison with control patients.

The influence of intraoral cryotherapy on postoperative pain and substance P in symptomatic apical periodontitis: randomized clinical study

Cryotherapy is widely utilized in medicine, particularly for pain management. This randomized clinical trial aimed to assess the effect of intraoral cold pack application (cryotherapy) on postoperative pain (POP) and the level of Substance P (SP) in patients with symptomatic apical periodontitis (SAP). Enrolled patients were randomly assigned to either cryotherapy or control group. After adequate anesthesia, access cavity, and biomechanical preparation of the root canal system were completed, the first apical fluid (AF) sample (S1) was obtained. A custom-made intraoral ice-gel pack was applied for 30 min in the cryotherapy group, while no intervention was performed in the control group. The second AF sample (S2) was collected 30 min later in both groups. Patients were asked to complete the Visual Analogue Scale (VAS) questionnaire to assess their POP. Quantification of SP in AF samples was performed using the enzyme-linked immunosorbent assay (ELISA) test. Data were analyzed statistically, revealing a significant reduction in POP and SP levels in the cryotherapy group compared to the control group (P ≤ 0.05). Furthermore, a moderate positive correlation was observed between SP levels and POP (P ≤ 0.05). In conclusion, intraoral cryotherapy represents a simple and cost-effective option for controlling POP and reducing inflammation levels in patients with SAP.

Incidence of Postoperative Flare-Up After Single-Visit and Multi-visit Endodontic Therapy

This article presents results obtained from a survey, including patients who underwent endodontic treatment by the single-visit or multi-visit method, after confirmation of the diagnosis of chronic apical periodontitis.

OBJECTIVE

The aim of the survey was to obtain data from the studied patients on the frequency and the type of postoperative pain after treatment of chronic apical periodontitis, as well as whether there is a relation between gender, age, and postoperative pain.

MATERIALS AND METHODS

A visual analog scale was used to study the intensity of postoperative pain in the treatment of teeth diagnosed with CPP, which are treated by one of two methods - single-visit or multi-visit method. The total number of surveyed patients is 71. The patients were examined and treated at the Dental Clinic "Imperial" in Varna, Bulgaria, in 2020. Thirty-one of them were treated by the single-visit method, and the remaining 40 by the multi-visit method with placement of a temporary dressing or sterile swab.

RESULTS

A relatively large proportion (70%) of patients reported mild pain immediately after the root canal filling. A relatively large proportion (90.3%) of patients did not report pain one week after the root canal filling. The more frequent symptoms were observed in cases treated by the multi-visit method, after the application of a temporary dressing. Patients who reported taking analgesics were treated in the multi-visit method. More frequent pain symptoms with both methods of treatment were observed in men aged 36-60 years.

CONCLUSION

Although exacerbation has been shown to have no significant effect on the outcome of endodontic treatment, it is highly undesirable. In the short term, the postoperative pain in patients treated by the multi-visit method through the use of intracanal medication is more pronounced. Patients receiving the single-visit treatment reported less postoperative pain.

Management of Endodontic Flare-Up in the Presence of Periapical Radiolucency: Case Report and Overview

Flare-ups following root canal therapy (RCT) are of significant concern in dentistry. They are characterized by the occurrence of pain or swelling during or even after a root canal procedure. They affect a considerable proportion of cases, up to 16% and occasionally even 50%, and they often necessitate unscheduled appointments. Whenever a flare-up occurs within hours or days following RCT, it demands emergency treatment. Flare-ups can be attributed to multiple factors, including mechanical, chemical, and microbial causes. Identifying these factors beforehand and utilizing the expertise of clinicians can help better manage patients after the procedure and assure a long-term successful outcome. It has been observed that retreatment cases with periapical periodontitis treated in a single appointment have higher flare-up rates. Despite the prevalence and the impact of flare-ups, the endodontic community has yet to adopt scientifically validated and approved preventive measures to manage and prevent flare-ups. Hence, in this case report, the ethical letter was approved (TUCDREC/250923). It provides insight into the management of an interappointment flare-up with an overview.

Effectiveness of root canal instrumentation for the treatment of apical periodontitis: A systematic review and meta-analysis

BACKGROUND

The development of endodontic instruments has rapidly advanced, but their impact on endodontic outcome parameters remains unclear.

OBJECTIVES

This systematic review aimed to answer the following PICOT questions: In patients with apical periodontitis (P) what is the effectiveness of root canal instrumentation ([Q1] performed with contemporary techniques [I] in comparison with 'traditional' techniques [C]] and ([Q2] performed with contemporary engine-driven NiTi instruments [I] compared with other types of contemporary engine-driven NiTi instruments [with different design and/or technology] [C]) in terms of clinical and patient-related outcomes (O)?

METHODS

After PROSPERO protocol registration, a literature search was conducted using Clarivate Analytics' Web of Science, Scopus, PubMed and Cochrane Central Register of Controlled Trials. Grey literature and major journal contents were examined. Two independent reviewers performed the study selection, data extraction and appraisal of included studies. A quantitative meta-analysis was considered, and statistical heterogeneity and overall quality of evidence were assessed.

RESULTS

Nine studies were identified showing substantial methodological differences. Five studies addressed PICOT 1 and three PICOT 2, whereas one study aimed both. A random-effects meta-analysis model was considered for the outcome 'radiographic evidence of normal periodontal ligament space or reduction of apical lesion size' (PICOT 1) based on three studies with 332 evaluable participants and showed that contemporary instrumentation was associated with a more favourable outcome (p = .005) compared with root canal preparation with stainless steel instruments (odds ratio = 2.07 [95%-confidence interval = 1.25-3.44]) with no evidence of statistical heterogeneity (I2  = 0%) but low quality of evidence.

DISCUSSION

Albeit a few studies fulfilled eligible criteria, no study had a low risk of bias. Compelling evidence indicating significantly different outcome rates using different endodontic instruments when treating teeth with apical periodontitis is lacking.

CONCLUSIONS

In terms of healing, the results of the meta-analysis determined the higher effectiveness of root canal instrumentation performed with contemporary techniques in comparison with conventional stainless steel instruments in patients with apical periodontitis followed for a minimum of 1 year with low quality of evidence. No differences could be demonstrated between preparations with traditional stainless steel and contemporary NiTi instruments for other clinical and patient-related outcomes.

REGISTRATION

PROSPERO (CRD42021274642).

The influence of anxiety on pain perception and its repercussion on endodontic treatment: a systematic review

OBJECTIVE

To evaluate the influence of dental anxiety on the perception of pain before and during endodontic treatments.

MATERIALS AND METHODS

The PRISMA checklist was followed. A search was conducted in Scopus, Medline/PubMed, The Cochrane Library, and Web of Science databases. Based on PECOS criteria, the first outcome was a possible association between pre-operative pain and anxiety. The second outcome was a possible association between intraoperative pain and anxiety. The type of studies was observational. The JBI Critical Appraisal Checklist was used to evaluate the methodological quality of articles. The certainty of the evidence was analyzed using the GRADE approach.

RESULTS

Four articles were included with a total of 471 patients. Two studies found a positive association between pain and pre-endodontic treatment anxiety. Three studies investigated the relationship between anxiety and intraoperative pain; two identified an extremely significant positive association. One article noted that anxiety influences pain expectancy. The studies were of good quality as assessed by the JBI Critical Appraisal Checklist for cross-sectional studies. However, the certainty of the evidence was considered low and very low.

CONCLUSIONS

Dental anxiety can be directly associated with pre- and intraoperative pain during endodontic procedures.

CLINICAL RELEVANCE

It is necessary to identify patients with dental anxiety to employ therapies to bring their anxiety under control, avoiding the increase of endodontic infections, and the postponement and evasion of endodontic treatments.

Comparative evaluation of the effectiveness of intracanal and intraoral cryotherapy on postendodontic pain in patients with symptomatic apical periodontitis: A randomized clinical trial

Introduction

There is a rising need for controlling postendodontic pain (PEP) without using analgesics and other conventional methods.

Aims

The aim of the study is to compare the effectiveness of various cryotherapy applications on controlling PEP in patients with symptomatic apical periodontitis.

Methods

One hundred and eight patients were selected and preoperative pain and pain on percussion scores were recorded using Numeric Rating Scale (NRS) and Visual Analog Scale (VAS), respectively. After obtaining consent, the access cavity was prepared under local anesthesia. After cleaning and shaping, the patients were randomized into the following groups: Group A: Canals were given final irrigation with 20 mL room temperature saline solution for 5 min, Group B: Canals were given final irrigation with 20 mL cold (2°C-4°C) saline solution for 5 min, and Group C: After obturation and restoration procedures, small ice packs of size 2 cm × 2 cm × 2.5 cm (wrapped in sterile gauze) were placed intraorally on the vestibular surface of the treated tooth. At 6 h, postoperative pain was measured using NRS and at 24 h, pain and pain on percussion were measured using NRS and VAS, respectively.

Results

Data were analyzed using SPSS software. There was a significant reduction in postoperative pain in the intracanal and intraoral groups at 6 and 24 h when compared with the control group individually. There was no significant difference in postendodontic between intracanal and intraoral cryotherapy groups at 6 and 24 h.

Conclusions

Both intracanal and intraoral cryotherapy applications are effective in reducing PEP in patients with symptomatic apical periodontitis.

The Effect of Number of Visits, Use of Solvent and Gutta-percha Removal Technique on Postoperative Pain following Nonsurgical Endodontic Retreatment; A Systematic Review and Meta-analysis

Introduction

The nonsurgical endodontic retreatment (NERT) is the first choice of dental ministration when primary/initial endodontic treatment fails. The present study aimed to investigate the presence of postoperative pain (POP) after NERT in permanent asymptomatic teeth as well as possible factors associated with POP.

Materials and Methods

A comprehensive search of literature was performed in Pubmed/MEDLINE, Embase, Scopus and Web of Science databases, up to January 2023; including randomized clinical trials and prospective studies. The risk of bias was assessed with RoB 2.0 and ROBINS-I tools. Subgroups analyses were conducted to evaluate the differences in the incidence or level of POP between the number of visits, the use/not use of solvent, the removal technique of gutta-percha, and the period of POP analysis. Mean differences and confidence intervals (CI) of 95% were used as measures of effect, and meta-regression was used along with subgroup analysis. The certainty of evidence was assessed using GRADE, and the probability value of <0.05 was considered significant.

Results

Twenty-four studies were selected, with thirteen included in the meta-analysis. There was a statistical difference between the incidence of POP after 24 h (95% CI, 0.28 to 0.52) and one week (95% CI, 0.02 to 0.13) from the endodontic retreatment (P<0.01). However, there was no statistical difference between different techniques, number of visits and use of solvent (P>0.05) in the same period. In addition, the certainty of evidence was very low.

Conclusions

Post-operative pain is a common response to NERT, independent of the retreatment technique(s) applied, number of visits and use of solvent(s); with very low certainty of evidence as well as low risk of bias. Moreover, the current analysis showed a (very) serious risk of inconsistency and imprecision. However, POP was significantly reduced within 1 week of the NERT.

Post-operative Pain after Different Root Canal Irrigant Activation Methods in Patients with Acute Apical Periodontitis (Randomized Clinical Trial)

Objective To evaluate the degree of postoperative pain in patients with necrotic teeth with symptomatic apical periodontitis after applying ultrasonic irrigation or manual dynamic agitation. Methods Seventy-eight patients diagnosed with necrotic mandibular first molar with symptomatic apical periodontitis were randomly allocated into 1 of 3 separate groups (n=26); Manual Dynamic Agitation group, Ultra X group, or NaviTip group (control). After a single-visit root canal treatment and a specific method of agitation, depending on each group, the patients were given a questionnaire on which they would mark the degree of pain in a scale from 0 to 10 at 6, 12, 24, 48, 72 hours and 7 days post-operative. Data were statistically analyzed with a significance level of P ≤ 0.05. Results Final irrigation protocol including Ultrasonic agitation and NaviTip (control) groups showed significantly lower values of pain than the MDA group. There was a reduction in pain values by time in all groups. Conclusion There was significantly less pain associated with passive ultrasonic agitation and side vented needle (NaviTip) irrigation compared to Manual Dynamic Agitation.

New and Efficient Bioactive Glass Compositions for Controlling Endodontic Pathogens

Endodontic treatment aims to conserve teeth through removing infected tissue, disinfecting, and filling/sealing the root canal. One of the most important treatment steps is the removal of microorganisms to avoid reinfection and consequent tooth loss. Due to increased resistance to intracanal medications, new alternative procedures are needed. Thus, an intracanal medication is suggested using three bioactive glass (BG) compositions (BG1, BG2, and BG3) produced by the sol–gel method, with different molar contents of bactericidal oxides. The BGs were morphologically and physically characterized. Their ability to inhibit the growth of two oral pathogens responsible for the failure of endodontic treatments (E. faecalis and C. albicans) was also studied. The results suggest that BG2 and BG3 can inhibit the growth of E. faecalis after 48 h of incubation, and all BG samples have a significant effect on C. albicans survival.

Post-Operative Endodontic Pain Management: An Overview of Systematic Reviews on Post-Operatively Administered Oral Medications and Integrated Evidence-Based Clinical Recommendations

Endodontic treatment comprises the overall management of pre-, intra- and post-operative symptoms, including post-operative endodontic pain, considered as a complication susceptible of chronicization. Post-operative pain is very common and highly unpreventable and has a multi-factorial etiology and a potential pathogenic link to the acute inflammation of the periapical area, secondary to localized chemical, mechanical, host and/or microbial damage occurring during endodontic treatment. Considering the multitude of heterogeneous technical and pharmacological approaches proposed to control post-operative endodontic pain, the present study primarily comprised an overview of systematic reviews of systematic reviews of randomized clinical trials, summarizing findings on post-operatively administered oral medications for post-operative endodontic pain control, in order to note the most effective type and dosage of such drugs. Secondarily, a narrative review of the current evidence on technical solutions to be observed during endodontic treatment procedures, to control post-operative pain, was conducted to provide integrated evidence-based clinical recommendations for optimal post-operative endodontic pain management.

Comparative evaluation of postoperative pain and periapical healing after root canal treatment using three different base endodontic sealers - A randomized control clinical trial

BACKGROUND

The aim of the present study was to evaluate and compare the postoperative pain and periapical healing after root canal treatment using three different base endodontic sealers.

MATERIAL AND METHODS

Primary root canal treatment was initiated in 63 patients diagnosed with necrotic pulp and apical periodontitis, cleaning and shaping was completed in two visit and different base endodontic sealers were used for obturation were selected based on the random allocation of the participants to the following groups; Tubli-Seal, AH Plus and BioRoot RCS. Postoperative pain was recorded by using 100 mm visual analog scale at 24 h, 48 h, 72 h and 7 d after obturation. Digital periapical radiographic evaluation was done to assess rate of periapical healing at baseline, 1, 3 and 6 months. Statistical analysis was done using Kruskal Wallis test and one-way ANOVA.

RESULTS

The mean difference in the size of periapical lesions for Tubli-Seal (6.27, 13.41), AH Plus (3.86, 9.80) and BioRoot RCS (4.05, 10.22) at 3 months and 6 months respectively. The mean pain scores at 24 h for Tubli-Seal (17.94 ± 11.35), AH Plus (11.57 ± 11.18), BioRoot RCS (4.73 ± 7.72). At 48 h, Tubli-Seal (5.26 ± 9.04), AH Plus (1.57 ± 3.74) and BioRoot RCS (1.57 ± 3.74) respectively. The mean pain score at 72 h for Tubli-Seal was 2.63 ± 7.33 whereas none of the patients had reported pain in AH Plus and BioRoot RCS group. None of the patients had pain after 7 d of treatment.

CONCLUSIONS

BioRoot RCS showed less postoperative pain compared to AH Plus and Tubli-Seal and showed better periapical healing compared to AH Plus and Tubli-Seal at 3 and 6 months intervals respectively. Key words:BioRoot RCS, root canal obturation, root canal sealers, periapical periodontitis, Periapical healing, postoperative pain.

Pain and Avoidance during and after Endodontic Therapy: The Role of Pain Anticipation and Self-Efficacy

Background: Pain anticipation has been identified as a predictor of pain and avoidance with respect to endodontic therapy. Self-efficacy is also key to the development and maintenance of health behaviors and achieve patient adherence to treatment. However, the role of self-efficacy has not been studied yet in endodontic treatment. Methods: This study was conducted on 101 patients who needed root canal therapy. They had to fill a questionnaire before treatment registered pain anticipation and self-efficacy; during and after treatment were registered pain intensity and avoidance. Results: Pain anticipation explained pain during (Beta = 0.51, t = 5.82, p ≤ 0.001, [0.34, 0.69]) and after treatment (Beta = 0.38, t = 4.35, p ≤ 0.001, [0.21, 0.55]). Self-efficacy did not have an influence in pain values. Pain anticipation explained avoidance during (Beta = 0.51, t = 3.60, p ≤ 0.001, [0.23, 0.80]) and after treatment (Beta = 0.62, t = 4.29, p ≤ 0.001, [0.33, 0.91]). Self-efficacy had a significant role in avoidance during treatment (Beta = 0.12, t = 2.19, p ≤ 0.03, [0.01, 0.23]) with a strong moderation relationship between pain anticipation and avoidance when self-efficacy was medium (Beta = 0.44, t = 3.24, p = 0.002, [0.17, 0.72]) or high (Beta = 0.84, t = 3.5, p ≤ 0.001, [0.37, 1.33]). Self-efficacy was not significant respect to avoidance after treatment. Conclusions: Self-efficacy is an important variable in endodontic therapy due to their moderating effect between pain anticipation and avoidance behavior during the procedure. It is necessary to improve the results of root canal therapy and reduce patient’s avoidance in order to take into account this variable.

Is Intracanal Cryotherapy Effective in Reducing Postoperative Endodontic Pain? An Updated Systematic Review and Meta-Analysis of Randomized Clinical Trials

This research aimed to assess the potency of intracanal cold therapy in diminishing postoperative endodontic pain. PubMed, Scopus, the Cochrane Library, EMBASE, the Web of Science, grey literature, and endodontic journals were used to identify randomized controlled clinical trials evaluating postoperative pain after a final irrigation with a cold irrigant (as an experimental group) and a room temperature irrigant (as a control group). The risk of bias was rated according to the Cochrane Collaboration's tool and the Grading Recommendation Assessment, Development, and Evaluation (GRADE) system was used to estimate the evidence quality. For the meta-analysis, a random effects model was utilized. The qualitative analysis contained 16 studies and the quantitative analysis contained 9 studies. The experimental groups showed a reduction in postoperative pain at 6 h (mean difference (MD) = -1.11; p = 0.0004; I2 = 72%; low quality evidence), 24 h (MD = -1.08; p = 0.003; I2 = 92%; low quality evidence), 48 h (MD = -0.38; p = 0.04; I2 = 81%; low quality evidence), and 72 h (MD = -0.69; p = 0.04; I2 = 90%; low quality evidence). A higher quality of evidence from more clinical trials is needed.

Predicting postoperative pain following root canal treatment by using artificial neural network evaluation

This study aimed to evaluate the accuracy of back propagation (BP) artificial neural network model for predicting postoperative pain following root canal treatment (RCT). The BP neural network model was developed using MATLAB 7.0 neural network toolbox, and the functional projective relationship was established between the 13 parameters (including the personal, inflammatory reaction, operative procedure factors) and postoperative pain of the patient after RCT. This neural network model was trained and tested based on data from 300 patients who underwent RCT. Among these cases, 210, 45 and 45 were allocated as the training, data validation and test samples, respectively, to assess the accuracy of prediction. In this present study, the accuracy of this BP neural network model was 95.60% for the prediction of postoperative pain following RCT. To conclude, the BP network model could be used to predict postoperative pain following RCT and showed clinical feasibility and application value.

Extrusion of debris with and without intentional foraminal enlargement - A systematic review and meta-analysis

This systematic review and meta-analysis was sought to assess whether intentional foraminal enlargement (IFE) is responsible for extrusion of a larger quantity of debris from extracted human teeth with fully formed apexes. Following the recommendations of Preferred Reporting Items for Systematic Review and Meta-Analysis - PRISMA, electronic and manual searches were performed to identify studies that evaluated the extrusion of debris, comparing different apical limits of instrumentation (with/without IFE). The quality of the studies selected was evaluated, and statistical analysis was conducted. To perform the meta-analysis, just 3 papers could be used. The heterogeneity was high, however; there was no statistically significant difference in relation to the extrusion of debris in teeth either submitted or not submitted to IFE. The general risk of bias was moderate. In conclusion, IFE is not responsible for extrusion of a larger quantity of debris from extracted human teeth with fully formed apexes.

Influence of maintaining apical patency in post-endodontic pain

BACKGROUND

The concept of instrumentation beyond the apical foramen by small flexible file to prevent apical blockage is apical patency. However, this procedure might endow postoperative pain, thus to maintain apical patency or not is the matter of dilemma. Hence, the primary objective of this study was to compare postoperative pain between apical patency and non-patency groups and secondary objective was to evaluate the influence of number of visits, vitality of teeth, group of teeth and preoperative pain on post-operative pain.

METHODS

Preselected (n = 178) patients based on group of teeth and status of pulp were randomly divided into 2 groups, apical patency and non-patency which was further treated in either single or multiple visits. After exclusion, 160 patients were included. Each group (n = 80) was subdivided in single visit (n = 40) and multiple visits (n = 40), including vital (n = 20) and non-vital teeth (n = 20) and single-rooted (n = 10) and multiple-rooted teeth (n = 10). Apical patency was maintained with a size 10 K-file during conventional hand filing step-back shaping procedure. Intensity of pain was recorded before treatment and on days 1, 2, and 7 after treatment using Numerical Rating Scale (NRS-11). Statistical analysis was done using Mann-Whitney U test, Spearman correlation and Multiple linear regression analysis.

RESULTS

The primary outcome of this study showed statistically significant difference (p < 0.05) in postoperative pain scores between patency and non-patency groups with higher pain scores in patency group on 1st, 2nd and 7th day follow up. The secondary outcome showed postoperative pain in patency-maintained group was influenced by status of the pulp and preoperative pain only. Vital teeth of patency-maintained group treated in multiple visits showed statistically significant (p = 0.02) post-operative pain in day 1 follow up. Pre-operative pain showed positive correlation with postoperative pain with statistically significant difference.

CONCLUSIONS

Our study concluded that maintenance of apical patency increased postoperative pain. Evaluation of influence of number of visits, status of pulp, group of tooth and preoperative pain revealed status of pulp and preoperative pain as influencing factors for postoperative pain in patency group.

Effect of Neem (Azadirachta indica) versus 2.5% sodium hypochlorite as root canal irrigants on the intensity of post-operative pain and the amount of endotoxins in mandibular molars with necrotic pulps: a randomized controlled trial

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.

Effect of intracanal cryotherapy on postendodontic pain: a systematic review and meta-analysis of randomized controlled trials

This systematic review aimed to qualitatively and quantitatively evaluate the effectiveness of cryotherapy in the reduction of postendodontic pain. The review question was, "What will be the success rate of cryotherapy technique among human patients with postendodontic pain?". The review protocol was framed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist. Six studies were included in the review, and quantification of five studies was performed through a meta-analysis. In the forest plot representation of the studies comparing the control and cryotherapy groups in terms of the success rate in the management of postendodontic pain, the combined risk ratio (RR) was 0.80 (95% CI: 0.56 to 1.13) with a P value of 0.20. Based on the quantitative analysis, it can be suggested that intracanal cryotherapy does not play a significant role in reducing postendodontic pain.

Effect of intracanal cryotherapy application on postoperative endodontic pain: a systematic review and metaanalysis

OBJECTIVES

To assess the influence of intracanal cryotherapy application on postoperative pain after endodontic treatment.

MATERIALS AND METHODS

A systematic review (SR) was conducted in seven databases. Articles that were published up to 04 February 2020 were included and randomized clinical trials that used a cold saline solution for final irrigation to manage postoperative endodontic pain were compared with those that used a saline solution at room temperature. Metaanalysis was performed to assess postoperative pain after 6, 24, 48, and 72 h using a random effects model, a confidence interval of 95%, and heterogeneity tested by the I² index. The certainty of evidence was rated using GRADE.

RESULTS

Qualitative and quantitative analysis included eight and six studies, respectively. Individuals treated with cryotherapy presented lower means of postendodontic pain than the controls, 6 and 24 h after endodontic treatment (MD - 1.30 [- 2.32, - 0.28] p = 0.01 and SMD - 0.68 [ - 1.21, - 0.16] p = 0.01, respectively, with very low certainty of evidence). After 48 and 72 h, both groups demonstrated similar means of postendodontic pain (MD - 0.06 [- 0.18, 0.07] p = 0.38 and SMD - 0.54 [- 1.18, - 0.11] p = 0.10, with high and low certainty of evidence, respectively).

CONCLUSIONS

Based on the limited quality evidence, intracanal cryotherapy application reduced postoperative endodontic pain after 6 and 24 h. New clinical trials are needed to support the result of this review.

CLINICAL SIGNIFICANCE

This SR provides information about the use of intracanal cryotherapy in clinical practice, guides clinicians to make evidence-based decisions and suggests recommendations for further high-quality studies.