Prevalence of inter-appointment endodontic flare-ups and host-related factors

The effect of apical patency on postoperative pain following endodontic therapy: A systematic review and meta-analysis

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.

Can instrumentation kinematics affect postoperative pain and substance P levels? A randomized controlled trial

BACKGROUND

This study aimed to assess the influence of continuous rotation and reciprocation kinematics on postoperative pain (POP) levels and substance P (SP) levels in patients diagnosed with irreversible pulpitis and symptomatic apical periodontitis (SAP).

MATERIALS AND SUBJECTS

A total of twenty patients were randomly assigned into two groups: Continuous Rotation Group (CRG) (n = 10), subjected to mechanical preparation with the EdgeEndox7 rotary system (Albuquerque, NM, USA), and Reciprocation Group (RG) (n = 10), treated with the EdgeOne Fire reciprocating system (Albuquerque, NM, USA). Apical fluid (AF) samples were collected, and SP levels were quantified through radioimmunoassay. POP was assessed using the Numerical Rating Scale (NRS) at various time intervals (preoperatively, 6 h, 12 h, 24 h, 48 h, and 72 h). Data were statistically analyzed utilizing the independent t-test, Mann-Whitney U test, Friedman's test, and Nemenyi post hoc test.

RESULTS

There was a significant increase in SP levels in the reciprocating group compared to the continuous rotation group (P ≤ 0.05). Additionally, patients in the reciprocating group reported significantly higher POP levels (P ≤ 0.05) at all measured intervals (6 h, 12 h, 24 h, and 48 h), with both groups exhibiting similar pain level reductions at the 72-hour mark.

CONCLUSION

Our findings suggest that continuous rotation kinematics in root canal preparation leads to a considerable reduction in SP expression and POP.

TRIAL REGISTRATION

The study protocol was retrospectively registered on the www.

CLINICALTRIALS

gov database (NCT06081335) at (13/10/2023) after the approval of the Ethics Committee, Faculty of Dentistry, Ain Shams University (FDASU-RecIM012135).

Postoperative pain of single-visit endodontic treatment with gutta-percha versus MTA filling: a randomized superiority trial

BACKGROUND

Postoperative pain has remained a challenge for clinicians. This randomized superiority trial compared the levels of postoperative pain following the use of gutta-percha (GP) and sealer or mineral trioxide aggregate (MTA) as root canal filling materials in teeth with asymptomatic apical periodontitis.

METHODS

A total of 119 patients were initially evaluated in this two-arm, parallel-group, single-blind, superiority randomized trial. The inclusion criteria were participants aged 18-65 years with single-canal premolars diagnosed with asymptomatic apical periodontitis. The participants were finally divided into two groups using the permuted block randomization method. In the GP group (N = 46), the cleaned and shaped root canals were filled with gutta-percha and AH Plus sealer, while in the MTA group (N = 48), the cleaned and shaped root canals were filled with an MTA apical filling and a coronal gutta-percha and sealer. Patient pain level was measured 6, 12, 24, 48, and 72 h postoperatively using a 10-point visual analog scale (VAS). The data were analyzed by the chi-square, independent t, Friedman, and Mann-Whitney U tests.

RESULTS

The mean of VAS scores decreased significantly over time in both groups (P < 0.001). The mean VAS scores were significantly lower in the MTA filling group than in the other group (P < 0.05). Female patients reported higher VAS scores at 6- and 12-hour periods in both groups (P < 0.05).

CONCLUSION

MTA as a root canal filling material might be a valuable option for clinicians due to its low postoperative pain.

TRIAL REGISTRATION

The trial protocol was registered at the Registry of Clinical Trials (IRCT20191104045331N1).

Flare-ups After Nonsurgical Retreatments: Incidence, Associated Factors, and Prediction

INTRODUCTION

The aims of this study were to determine the incidence, associated factors, and predictability of flare-ups after nonsurgical retreatments (NSRetx).

METHODS

All patients (n = 3,666) who received NSRetx by 3 endodontists in 2 endodontic offices during a period of 6 years (2016-2022) were included. Demographic, diagnostic, and procedural data were collected. A flare-up was defined as moderate-severe pain with/without swelling that took place within 14 days of initiation of NSRetx and resulted in an unscheduled appointment. Bivariate analyses on the entire cohort and multivariable analyses on cases with complete dataset (n = 2,846) were performed to identify significant associations. A Random Forest algorithm was used to make a prediction model.

RESULTS

Incidence of flare-ups was 3.95% (n = 145). Increased risk of flare-ups was associated with diabetes (adjusted odds ratio [AOR] = 2.01; 95% confidence interval [CI], 1.01-3.97), mandibular teeth (AOR = 1.67; 95% CI, 1.11-2.52), moderate-severe preoperative pain on percussion (AOR = 2.13; 95% CI, 1.31-3.50), and pain on palpation (AOR = 1.63; 95% CI, 1.01-2.64). Lower risk of flare-up was associated with high blood pressure (AOR = 0.44; 95% CI, 0.21-0.82) (P < .05). The prediction model was not able to predict flare-ups with sufficient confidence (precision = 0.13).

CONCLUSIONS

Incidence of flare-ups following NSRetx was low (∼4%) and had a weak but significant association with the history of diabetes. Moderate-severe pain on percussion, pain on palpation (any intensity), and mandibular teeth had a significant association with flare-ups. The history of high blood pressure was associated with lower risk of flare-ups. Flare-ups were difficult to predict in this clinical setting.

Postoperative pain perception and associated risk factors in children after continuous rotation versus reciprocating kinematics: A randomised prospective clinical trial

To compare the postoperative pain of continuous rotation and reciprocating movements after pulpectomy of non-vital primary molars and determine associated risk factors. 146 children aged 4-8 years with one primary molar indicated for pulpectomy were randomly assigned to two equal groups: those instrumented with continuous rotation motion (Hyflex EDM Coltene/Whaledent) and reciprocating motion (Reciproc R25 (VDW)). A 4-point pain scale was used to assess postoperative pain frequencies, which were compared at different intervals using the Chi-square test. Postoperative pain risk factors were determined using logistic regression analysis. There was no statistically significant difference between the follow-ups. Gender, pulp status, and radiographic radiolucency increased the risk of postoperative pain incidence. Postoperative pain likelihood in children with chronic apical periodontitis was 8.72 times that of children with necrotic pulps. Postoperative pain after instrumentation with both kinematics was comparable. Postoperative pain incidence is increased by preoperative pulp condition, radiographic radiolucency, and gender.

Incidence of interappointment emergencies in multiple-visit root canal treatments performed with or without intracanal medicament by undergraduate students

Objectives

This retrospective cohort study examined the incidence of interappointment emergencies during multiple-visit molar root canal treatments conducted by undergraduate students. Treatments performed without the use of intracanal medicament were compared to treatments that incorporated calcium hydroxide as an intracanal medicament.

Materials and Methods

Interappointment emergencies, defined as instances of pain or swelling that required the patient to make an unscheduled follow-up visit, were recorded for up to 2 months after the intervention. To avoid the influence of obturation on the observed incidence of emergency visits, only unscheduled visits occurring between the start and end of the root canal treatment were included.

Results

Of the 719 patients included in this study, 77 (10.7%) were recorded as experiencing interappointment emergencies. Of these emergencies, 62% occurred within 2 weeks following the most recent intervention. In the group of patients who did not receive intracanal medicament, the incidence of interappointment emergencies was 11.9% (46 of 385 patients). In comparison, this rate was 9.3% (31 of 334 patients) among those who received calcium hydroxide as an intracanal medicament (odds ratio, 1.33; 95% confidence interval, 0.82-2.15; p = 0.249).

Conclusions

Interappointment emergencies may arise at any point during root canal treatment, but they most commonly occur within the first 2 weeks following intervention. The omission of intracanal medicament in multiple-visit molar root canal treatments, performed by undergraduate students, did not significantly increase the incidence of these emergencies.

DENTAL PATIENT-REPORTED OUTCOMES IN ENDODONTICS - A NARRATIVE REVIEW

Recently in oral health care settings, the focus of assessing treatment outcomes has shifted from the perspective of the clinician towards that of the patient. Endodontology is a specialty of dentistry concerned with the prevention and treatment of pulp and periapical diseases. Research in endodontology and its associated treatment outcomes have focused mainly on clinician-reported outcomes (CROs) and not dental patient-reported outcomes (dPROs). As a result, there is a need to emphasize the importance and relevance of dPROs to researchers and clinicians. The aim of this review is to present an overview of dPROs and dPROMs within endodontics in an attempt to create a better understanding of the patient experience, highlight the need to place the patient at the center of treatment, enhance patient care and encourage more research into dPROs. The key dPROs following endodontic treatment include pain, tenderness, tooth function, need for further intervention, adverse effects (exacerbation of symptoms, tooth discoloration) and Oral Health-Related Quality of Life. dPROs are important following endodontic treatment because they assist clinicians and patients when they discuss and select the most appropriate management options, help clinicians make decisions on pre-operative assessment, prevention and treatment, and improve the methodology and design of future clinical studies. Clinicians and researchers in endodontology should prioritize patient welfare and undertake routine analyses of dPROs using appropriate and robust measures. Due to the lack of agreement over the reporting and definition of endodontic treatment outcomes, a comprehensive project to define a ``Core Outcome Set for Endodontic Treatment Methods (COSET)'' is currently ongoing. In the future, a new and exclusive assessment tool should be developed to reflect the viewpoints of patients receiving endodontic treatment more accurately.

Vital Pulp Therapy of Permanent Teeth with Reversible or Irreversible Pulpitis: An Overview of the Literature

Vital pulp therapy (VPT) has been recently proposed as an alternative approach even in symptomatic mature permanent teeth with deep caries’ lesions, aiming to maintain the pulp vitality over time and/or to avoid non-surgical root canal therapy (NSRCT). However, to date, the diagnosis of reversible or irreversible pulpitis is only based on clinical pain quantity and quality, without precisely reflecting the pulp inflammation status. Therefore, the aim of the present study was to provide an overview based on the current scientific literature to demonstrate the clinical effectiveness of VPT on mature permanent teeth, validating the use of hydraulic calcium silicate-based cements and their role in pain management. VPT may be successfully applied not only in mature permanent teeth diagnosed with reversible pulpitis, but also in permanent dental elements with signs and symptoms of irreversible pulpitis. Hydraulic cements showed favorable outcomes in terms of decrease of pro-inflammatory mediators and of post-operative pain. Pain plays a central role in the chance to perform VPT in mature permanent teeth, since it may be considered as a pre-operative diagnostic criterion as well as a treatment success parameter. In addition, proper assessment of pulp inflammation and choice of appropriate materials are key factors in enhancing VPT success.

The Effect of Passive Ultrasonic Irrigation or XP-Endo Finisher on Post-Operative Pain in Patients with Necrotic Teeth with Apical Periodontitis (Randomized Controlled Clinical Trial)

Objective To evaluate the effect of passive ultrasonic irrigation or XP-Endo Finisher on post-operative pain in patients with necrotic teeth with apical periodontitis using (VAS) scale at 6, 12, 24, 48, 72 hours, and 7 day time intervals. 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); Navitip group (control), XP-Endo Finisher group, or Ultra X group. 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 the patient would mark the degree of pain in a scale from 0 to 10 at 6, 12, 24, 48, 72 hours and 7 days post-obturation. Data were statistically analyzed with a significance level of P ≤ 0.05. Results Ultrasonic agitation and XP-Endo Finisher agitation as a final irrigation protocol showed significantly lower pain values than the control group, but there was no significant difference in pain values between the experimental groups. Conclusion There was significantly less pain associated with ultrasonic and XP-Endo Finisher agitation compared to Navitip irrigation.

Endodontic pulp revitalization in traumatized necrotic immature permanent incisors: Early failures and long-term outcomes - a longitudinal cohort study

Aim

This prospective cohort study evaluates clinical and radiographical outcomes of endodontic pulp revitalization (PR) of traumatized necrotic incisors.

Methodology

Pulp revitalization was performed in 75 traumatized necrotic immature incisors from 71 patients. The radiographic outcome measures were continued root formation (width and length), root resorption, apex closure, periapical index, and root development stage. The clinical outcome measures were percussion pain, palpation pain, pathological tooth mobility, swelling, sinus tract, ankylosis, crown discolouration, response to pulp sensitivity test, and subjective pain. Treatment outcomes were categorized as a success based on the absence of clinical symptoms and when radiographic evidence was present for apical healing and continued root development. The performed statistical tests were repeated measures anova, pairwise comparisons of interactions (t‐test), McNemar's test, and linear regression model.

Results

In 45 of 75 teeth (60%), PR was successful with the resolution of clinical and radiographic signs and continued root development. PR failed due to the absence of bleeding (n = 19) and persistent infection (n = 11). PR showed statistically significant increases in root length (11%), and dentinal wall thickness (30%), root maturation (pre‐operative 3.38 [CI 1.88; 4.88]; post‐operative 4.04, [CI 2.56; 5.52]) apical closure (71.4%), healing of pre‐operative apical periodontitis (100%), and healing of pre‐operative inflammatory root resorptions (100%). Three predictive variables for continued root maturation were identified – root development stage at entry (p = .0001, β 0.649), [CI 0.431; 0.867], trauma to the soft tissues (p = .026, β −0.012), [CI −0.0225; −0.015], and pre‐operative dentinal wall thickness (p = .009, β −0.001); [CI −0.001; 0.0001].

Conclusions

Our findings indicate that PR provides satisfactory clinical and radiographical outcomes in traumatized necrotic incisors. The failed cases were related to lack of bleeding and persistent infections, indicating that new techniques are needed to improve the predictability of PR.

The effect of antibiotic use on endodontic post-operative pain and flare-up rate: a systematic review with meta-analysis

Aim Antibiotics are widely used to prevent flare-ups after endodontic treatment of non-vital teeth. This systematic review assessed the effect of antibiotic administration on post-endodontic treatment pain and flare-up rate.Methods Five major databases including Web of Science, Cochrane Library, PubMed, Scopus and Embase were searched to identify randomised clinical trials (RCTs) published until September 2020. Retrieved papers were critically appraised using the revised Cochrane risk of bias tool (RoB 2). To reduce the clinical heterogeneity, the included studies were divided into two groups: studies on symptomatic non-vital teeth and studies on asymptomatic non-vital teeth. The primary outcomes were 'post-operative pain' and 'flare-up rate'. The data of included studies were statistically combined through meta-analysis using random-effect model. The Grading of Recommendations, Assessment, Development and Evaluation (GRADE) approach was used to assess the quality of evidence.Results Six RCTs involving two RCTs (N = 61) on symptomatic teeth and four RCTs (N = 310) on asymptomatic teeth were included. In two RCTs on asymptomatic teeth, prophylactic antibiotic had been used, while in the remaining two RCTs, antibiotics had been administered after treatment. Quantitative synthesis of the RCTs showed that antibiotic administration following endodontic treatment of symptomatic non-vital teeth has no effect on pain severity at 24 hours following treatment (weighted mean difference [WMD] = -0.03; 95% confidence interval [CI]: -0.53 to 0.47), and the use of antibiotics before endodontic treatment of asymptomatic non-vital teeth has no effect on flare-up rate (relative risk [RR] = 0.58; 95% CI: 0.22-1.54). The GRADE approach revealed that the overall quality of evidence on the topic is low.Conclusions The antibiotic administration following endodontic treatment of symptomatic non-vital teeth has no effect on pain severity at 24 hours following treatment. Also, prophylactic antibiotics are ineffective in reducing the flare-up rate following treatment of asymptomatic non-vital teeth. However, to evaluate the effect of post-treatment antibiotics on flare-up rate in asymptomatic non-vital teeth, more high-quality RCTs are needed.

Present status and future directions - managing endodontic emergencies

Endodontic emergencies are common in both general dental practices and specialist Endodontic practices. The aim of this review is to provide an overview of endodontic emergencies. Endodontic emergencies can be a result of many different conditions of the pulp, root canal and periradicular tissues. They may occur before endodontic treatment has been started, between appointments when treatment is being performed over multiple visits, or after endodontic treatment has been completed. In the latter situation, the emergency may be very soon after the treatment or it may occur many years later, in which case it is usually a new disease process as a result of the root canal system becoming infected. An emergency can be a stressful situation for both the patient and the dentist (or endodontist) as it is usually an unexpected event. It is incumbent on dental professionals to provide timely assistance to patients who have an emergency, and it is also important to allow sufficient time to manage the situation comprehensively. Management of endodontic emergencies should follow the principles of the 3D's - Diagnosis, Definitive dental treatment and Drugs - and in that sequence. An accurate diagnosis, the first "D", is essential so the appropriate treatment can be provided. Diagnosis requires a thorough understanding of the various conditions that can cause the emergency and this can be helped by having a comprehensive classification of the various conditions. The diagnosis should also direct the clinician to the appropriate definitive dental treatment, the second "D". Root canal treatment will not always be required as some cases can be managed conservatively. Other cases may require root canal re-treatment. The specific details of how the treatment is done can also vary, according to the diagnosis. The final "D" is Drugs - the use of drugs should also be dependent on the diagnosis and the dental treatment. Drugs should only be an adjunct following the treatment. The clinician must also differentiate between inflammation and infection in order to provide the appropriate treatment and to prescribe the appropriate medication for effective pain relief and resolution of other symptoms or signs such as swelling.

Endodontic postoperative flare-up: An update

Endodontic treatment corresponds to a combined chemical and mechanical approach, followed by a three dimensional hermetic obturation, that eliminate the pulpal and periradiculare disease and boost healing and repair of periradiculare tissue. Despite the advances in the endodontic field, the inter-appointment flare up remains a true nightmare that encounters every dentist. This complication commences a few hours or days after root canal procedures and it is characterized by the development of pain and/or swelling, requiring an unscheduled appointment for emergency treatment. Different studies showed that flare-ups represent a multifactorial phenomenon including mechanical, chemical and microbial factors. In addition, a correlation was found between flare-up and age, gender, tooth type, presence of preoperative pain, tooth condition before treatment, irrigation techniques, number of visits as well as intracanal medication. Moreover, some medicine intake was proved to be efficient in controlling this postoperative pain. However, a clear procedure to avoid its occurrence is yet to be established. In this review, we summarize knowledge about the etiology of flare-up and its related factors. This could be effective in helping dentists to adapt some strategies to prevent it.

The antibacterial effect and the incidence of post-operative pain after the application of nano-based intracanal medications during endodontic retreatment: a randomized controlled clinical trial

OBJECTIVE

This clinical trial aimed to evaluate the effect of nano-silver and nano-calcium hydroxide intracanal medicaments (ICM) during retreatment regarding their antibacterial effect and their effect on post-operative pain and flare-ups.

MATERIALS AND METHODS

Sixty-nine patients scheduled for endodontic retreatment were included in this randomized clinical trial and randomly allocated to 3 equal groups (n = 23) according to the type of ICM used. The first microbial sampling (S1) representing the original microbiota was obtained after the removal of the old canal filling. After chemo-mechanical debridement, another sample (S2) was obtained representing the microbial state before ICM application. Patients were randomly allocated to receive either nano-silver (nano-Ag), nano-calcium hydroxide (nano-CH), or calcium hydroxide (CH) as ICM. Patients rated their pain pre-operatively and then after 6, 12, 24, 48, and 72 h. During the second visit (7 days later), the last microbial sample (S3) was obtained after removal of the ICM. Reduction of total bacterial and total E. faecalis counts and the biofilm-forming capability of the existing microbiota were determined.

RESULTS

Results showed reduction in total bacterial count, total E. faecalis count and the biofilm-forming,capability of the existing microbiota after chemo-mechanical debridement (S1-S2) and after the application of ICM (S3-S2). However, the reduction after cleaning and shaping was significantly more pronounced (p < 0.001) compared to the effect of ICM application, with no difference between the 3 ICM (p > 0.05). Post-operative pain was significantly reduced at the 48- and 72-h intervals after the application of nano-Ag and nano-CH only (p < 0.001), with no significant difference between these two ICM (p > 0.05). The incidence of flare-ups in all groups was similar (p > 0.05).

CONCLUSIONS

The antibacterial effect of the nano-Ag and nano-CH was equivalent to that of CH, but they contributed to better pain control.

CLINICAL RELEVANCE

Nanoparticles may have a positive impact on post-endodontic pain.

Effect of XP-endo Shaper versus conventional rotary files on postoperative pain and bacterial reduction in oval canals with necrotic pulps: a randomized clinical study

AIM

To assess postoperative pain and bacterial reduction following the use of XP-endo Shaper versus conventional rotary files in preparation of oval canals with necrotic pulps.

METHODOLOGY

This superiority, parallel, randomized, double blinded clinical trial was conducted in the clinic of the Endodontic Department, Faculty of Dentistry, Cairo University, Egypt. Sixty single-canalled mandibular premolars with necrotic pulps were randomly assigned into two equal groups. Canals were instrumented using XP-endo Shaper files in the intervention group and iRaCe rotary files in the control group. Bacterial samples were taken before and after canal instrumentation. Incidence and severity of postoperative pain was assessed using a modified VAS after 6, 12, 24 h and daily for 5 days. A culture method was used to assess the number of bacterial colony forming units. Incidence of analgesic intake as well as flare-ups was recorded. Data were analysed using chi-square, Fisher Exact, Mann-Whitney, Independent t-test, and Spearman's correlation for pain and bacterial counts.

RESULTS

The XP-endo Shaper compared with the iRaCe group was associated with a significantly lower incidence of postoperative pain at 6, 12, and 24 h (P = 0.039, 0.047, and 0.026, respectively), and severity of postoperative pain at 6 h (mean difference: 1.33, 95% CI: 0.307-2.352, P = 0.02), 12 h (mean difference: 1.1, 95% CI: 0.26-1.936, P = 0.007), 24 h (mean difference: 0.94, 95% CI: 0.178-1.701, P = 0.008) and 48 h (mean difference: 0.97, 95% CI: 0.192-1.747, P = 0.038). There was a significant decrease in bacterial count following canal instrumentation in both groups (P < 0.001) with no significant difference between them (mean difference: 0.83 × 10⁵ , 95% CI: 0.336 × 10⁵ -1.996 × 10⁵ , P = 0.56). A weak correlation existed between postoperative pain severity and bacterial counts (P = 0.54). There was no significant difference in analgesic intake between the two groups (P = 0.085). Flare-ups occurred in 3.3% of teeth in the iRaCe group, while no flare-ups occurred in the XP-endo Shaper group.

CONCLUSIONS

XP-endo Shaper was associated with a significantly lower frequency of postoperative pain for up to 24 h, and lower severity of postoperative pain for up to 48 h compared with iRaCe files. Both systems were equally effective in bacterial reduction from oval root canals with necrotic pulps.

Effect of Different Host-Related Factors on Postoperative Endodontic Pain in Necrotic Teeth Dressed with Interappointment Intracanal Medicaments: A Multicomparison Study

Objectives  The current study aimed to assess the impact of factors such as age, gender, and the tooth type on postoperative endodontic pain in necrotic teeth with symptomatic periapical periodontitis and radiolucency dressed randomly with either calcium hydroxide or propolis paste.

Materials and Methods  The standard chemomechanical root canal preparation of 80 teeth was performed by the primary investigator. The intracanal medicaments were inserted by the secondary operator. Patients self-recorded their postoperative endodontic pain intensity with the help of visual analog scale at 4, 12, 24 (day 2), 48 (day 3), and 72 (day 4) hours. During analysis, patients (68/80) were grouped according to gender, age, and the tooth type.

Statistical Analysis  Mann–Whitney’s U test was applied for mean pain score comparison between genders and between tooth type. Kruskal–Wallis’ test was applied for mean pain score comparison between the age groups.

Results  No significant difference ( p > 0.05) in pain scores was found between the age groups and between the tooth types. Males had significantly higher pain scores as compared with females at days 2 ( p = 0.035), 3 ( p = 0.023), and 4 ( p = 0.020).

Conclusion  The results suggested that there was no impact of age and tooth types on postoperative endodontic pain.

The top risk factors for endodontic flare-up: a Monte Carlo simulation

OBJECTIVES

The aim of this study was to analyze the strength of risk factors related to endodontic flare-ups and rank them in order of their importance MATERIALS AND METHODS: A systematic literature search of PubMed, Cochrane Central Register of Controlled Trials, Scopus, and ISI Web of Knowledge, and grey literature was conducted up to November 2019. One hundred ninety-eight publications were identified. Twelve records fulfilled the eligibility criteria, and eight significant risk factors for flare-up, namely, "Periapical lesion," "multiple-visit treatment," "preoperative pain," "necrotic teeth," "female gender," "retreatment," "percussion pain," and "analgesics," were selected to construct the simulation model. The final data pool was established by the integration of data of common risk factors in the included articles. Monte Carlo method was used to analyze of combined numerical data, for simulation of the risk factor impacts. Ten thousand iterations were generated in the simulation model.

RESULTS

The results of the simulation revealed that the risk estimates of the factors had varying ranges of influence and probability on the flare-up risk. "Periapical lesion" was found to be the most sensitive risk factor, following by "preoperative pain" which was ranked the second place. The third-ranked risk factor was "multiple-visit treatment." The least sensitive risk factors for endodontic flare-up were "retreatment," "female gender," "necrotic teeth," and "analgesics."

CONCLUSIONS

The present study provides better comprehension on the importance of risk factors for flare-up based on their risk estimates.

CLINICAL RELEVANCE

A Monte Carlo simulation was adopted to identify the most influential risk factors for endodontic flare-up with a ranking, which can be used to provide meaningful predictions and further insights into clinicians' perception of flare-up risk.

Effect of Chinese Propolis as an Intracanal Medicament on Post-Operative Endodontic Pain: A Double-Blind Randomized Controlled Trial

Propolis is a potent anti-microbial and natural anti-inflammatory by-product obtained from the beehive. Studies have demonstrated the superior biocompatibility and anti-microbial properties of propolis as compared to calcium hydroxide. However, its effect on postoperative endodontic pain is unknown. Therefore, this study aimed to investigate the impact of Chinese propolis paste as an intracanal medicament on postoperative endodontic pain intensities compared with calcium hydroxide (control) at different time intervals in necrotic teeth with periapical radiolucency. Eighty patients with single-rooted necrotic teeth with visible periapical radiolucency were recruited and randomly allocated to either the calcium hydroxide or propolis groups. After chemo-mechanical preparation and intracanal medicament insertion, patients were given the VAS (visual analogue scale) to record pain scores. Inter-group data were compared and analyzed using two-way repeated measure ANOVA (Bonferroni test). A p-value of < 0.025 was considered significant. In total, >78% of the patients experienced no or only mild post-operative pain in both the groups at all time intervals, without any significant difference in pain scores between the two groups (p > 0.025). An overall flare-up rate of 14.8% was found. The results suggest that either of these medicaments can be used as an inter-appointment medication for the prevention of postoperative pain in necrotic cases.

Evaluation of Apically Extruded Debris Using Positive and Negative Pressure Irrigation Systems in Association with Different Irrigants

This study evaluated the amount of apically extruded debris after chemo-mechanical preparation (CMP) using positive and negative pressure irrigation systems [Conventional irrigation (CI) and EndoVac (EV)] in association with different irrigants [6% Sodium Hypochlorite (NaOCl), 2% Chlorhexidine gel + saline solution (CHXg + SS), 2% Chlorhexidine solution (CHXs) or Saline solution (SS)]. Eighty mandibular premolars with single root canals were selected and randomly assigned into 8 groups (n = 10) according to the irrigation system and the irrigant used during CMP: G1 (EV + NaOCl), G2 (EV + CHXg + SS), G3 (EV + CHXs), G4 (EV + SS), G5 (CI + NaOCl), G6 (CI + CHXg + SS), G7 (CI + CHXs) and G8 (CI + SS). Reciproc® R25 files (25/.08) were used during the CMP and the extruded debris from each tooth was collected in pre-weighted Eppendorf tubes and dried. The average weight of debris was assessed using a microbalance, and the data were statistically analyzed using ANOVA and the post hoc Tukey's test (a = 0.05). All groups were associated with debris extrusion. EV was the irrigation system with less extruded debris (p < 0.05). No differences were observed regarding the irrigant when EV was used. When CI was used, CHXg + SS were associated with lower debris extrusion (p < 0.05). It was concluded that no irrigation protocol succeeded in preventing debris extrusion. EV resulted in lower levels of debris extrusion than CI. The use of CHXg + SS resulted in lower debris extrusion.

Incidence of Endodontic Flare-ups and Its Related Factors: A Retrospective Study

Aims and Objectives:

The aim and objective of the study were to determine the incidence of flare-ups during endodontic treatment and to identify the risk factors associated with flare-ups.

Subjects and Methods:

A total of 1725 patients who were treated during the time period of 2009–2014 by the same endodontist were reviewed. Incidence of flare-up, patients' age, gender, status of pulp, tooth position, number of roots, and treatment provided were taken from their dental records. Relationship between these factors and flare-ups was examined. Statistical analysis was done using Pearson Chi-square test and Fisher's exact test.

Results:

A total of 2% incidence of endodontic flare-ups was seen out of 1725 cases. Patient's age, gender, and diagnosis had a significant effect on the development of flare-ups (P < 0.05). Tooth type, position of tooth, number of root canals, number of visits, and treatment modality had no significant effect on flare-up incidence.

Conclusions:

Diagnosis plays an important role in predicting the incidence of flare-ups. Patients in the age group of 40–60 years had a higher risk of developing flare-ups. Women compared to men are more prone to flare-ups.