Postoperative pain following endodontic irrigation using 1.3% versus 5.25% sodium hypochlorite in mandibular molars with necrotic pulps: a randomized double‐blind clinical trial

Impact of Cryotreated and Warm Sodium Hypochlorite on Post-Operative Pain in Teeth with Symptomatic Irreversible Pulpitis: A Randomized Controlled Trial

INTRODUCTION

The purpose of this study was to evaluate effect of cryotreated and warm sodium hypochlorite (NaOCl) on post-operative pain in patients with symptomatic irreversible pulpitis and symptomatic apical periodontitis.

METHODS

Sixty-six individuals with pre-operative pain scores of ≥ 54mm on the Heft Parker Visual Analogue Pain Scale (HP-VAS) diagnosed with symptomatic irreversible pulpitis and symptomatic apical periodontitis as per the AAE guidelines in mandibular molars were included. The preparation of the access, and the root canals were instrumented and irrigated in accordance with a standard protocol. Based on the temperature of the final irrigant, the root canals were then randomly assigned to three groups and 3% NaOCl was irrigated: Control (at 25°C), cold NaOCl (2°C) and warm NaOCl (60°C) (n = 22/group). Root canal treatment was completed at the same visit. Pre- and post-operative pain assessment at 6, 24, 48, and 72 hours was conducted using HP-VAS, and analgesic consumption was noted. Suitable statistical tests were used to analyze the data.

RESULTS

In comparison to the other two groups, cold NaOCl group had a lower HP-VAS score at all follow-up intervals. Between groups, there was a statistically significant difference in post-operative pain scores at 6 and 72 hours (p < 0.05). None of the subjects experienced any postoperative discomfort at 72 hours in the control and cold NaOCl group.

CONCLUSION

Patients treated with cold NaOCl as the final irrigant experienced significantly lesser post-operative pain at 6 hours when compared to room temperature and warm NaOCl.

Sodium Hypochlorite Concentration and Postendodontic Pain - Unveiling the Optimal Balance: A Systematic Review and Meta-Analysis

INTRODUCTION

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.

METHODS

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.

RESULTS

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).

CONCLUSIONS

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.

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.

Postoperative pain after endodontic treatment using 8.25% vs 2.5% sodium hypochlorite in necrotic mandibular molars with apical periodontitis: A randomized double-blind clinical trial

BACKGROUND

This study aimed to evaluate whether the use of 8.25% sodium hypochlorite (NaOCl), compared with the use of 2.5% NaOCl, leads to higher postoperative pain after endodontic treatment.

METHODS

A total of 154 patients were randomly assigned into 2 groups: 8.25% and 2.5% NaOCl. A single-visit endodontic treatment was performed using a standard protocol, varying only the NaOCl concentration. Postoperative pain was assessed using the numeric rating scale at multiple times over 30 days. Overall pain scores over time were explored via multilevel mixed-effects negative binomial regression. The need for pain medication was recorded and compared between groups via the Mann-Whitney U test.

RESULTS

The use of 8.25% NaOCl increased postoperative pain scores over time by 3.48 times compared with the use of 2.5% NaOCl (incident rate ratio [IRR], 3.48; 95% CI, 1.57 to 7.67). Furthermore, the 8.25% NaOCl group exhibited higher pain incidence than the 2.5% NaOCl group during the 12-hour through 3-day period, with scores at these times ranging from 2.21 (IRR, 2.21; 95% CI, 1.35 to 3.62) through 10.74 (IRR, 10.74; 95% CI, 3.74 to 30.87) higher. No difference was detected in the number of analgesic capsules administered between groups.

CONCLUSIONS

The use of 8.25% NaOCl resulted in higher postoperative pain than the use of 2.5% NaOCl, with pain scores increasing by 3.48 times when this solution was used. Furthermore, the 8.25% NaOCl group exhibited higher pain incidence than the 2.5% NaOCl group during the 12-hour through 3-day period.

PRACTICAL IMPLICATIONS

The use of 8.25% NaOCl during endodontic treatment can increase postoperative pain significantly. This clinical trial was registered at the Brazilian Registry of Clinical Trials database (RBR-6vq3hc4).

Postoperative pain of minimally invasive root canal treatment:a randomized clinical trial

This randomized clinical trial compared postoperative pain between a minimally invasive (MP) and conventional root canal treatment protocol (CP). A total of 170 mature permanent teeth (either with vital or necrotic pulp), were randomly assigned into two groups. In the CP group, ProTaper Gold (Dentsply Sirona, Ballaigues, Switzerland) and a continuous wave of condensation technique were used, whereas, in the MP group, TruNatomy (Dentsply Sirona), ultrasonic-assisted irrigation (UI), calcium hydroxide, and a sealer-based obturation technique were used. Patients recorded preoperative and postoperative pain using a 0-10 numerical rating scale (NRS) at 4 h, 1, 2, 3, 4, 5, 6, and 7 days after instrumentation and 1 day after canal obturation, respectively. There were no significant differences in pain intensity at any time points assessed between the two groups (p > 0.05). The occurrence of moderate/intense pain after instrumentation was significantly associated with preoperative periapical index (PAI) (p = 0.017) and NRS scores (p < 0.001). Preoperative pulp status (p = 0.009) and NRS score (p = 0.006) were identified as significant factors in the occurrence of moderate/intense pain after obturation. Instrumentation unequivocally reduced pain severity for both groups. The post-endodontic pain associated with the use of MP, combined with UI, Ca(OH)2, and calcium-silicate cement, did not differ from that of CP. Preoperative pain score, PAI, and preoperative pulp status were determined to be prognostic factors for postoperative pain.

Comparative Evaluation of Dental Pulp Tissue Dissolution Ability of Sapindus mukorossi and Sodium Hypochlorite

Background The Sapindus mukorossi (SM) extract has been reported to possess antibacterial, antifungal, anti-inflammatory, and antioxidant characteristics. However, there is limited research demonstrating the effectiveness of SM in dissolving dental pulp tissue. Methods In an in vitro investigation, pulp tissue samples were extracted from human teeth, collectively weighing 144 mg. These samples were divided equally and activated by manual digital agitation (MDA) or ultrasonic (US) irrigation for three 30-second cycles with a resting period of 45 seconds between each activation. The samples in each group were sub-categorized into a set of three groups based on the treatment received as normal saline (NS), 5.25% sodium hypochlorite (Hypo), or Sapindus mukorossi (SM). Statistical tests, including the student t-test and one-way analysis of variance (ANOVA), were employed to compare the mean weight differences among the groups, with a significance level set at p ≤ 0.05 for all comparisons. Results The one-way analysis of variance (ANOVA) and independent t-test revealed significant intergroup differences (p<0.05). Turkey's post hoc analysis indicated significant distinctions, particularly when comparing Hypo with the other two irrigants, namely Hypo-NS (p<0.05) and Hypo-SM (p<0.05) when the MDA method was employed. Considering only the method adopted, the US technique was significantly superior (p=0.04) to the MDA. Conclusion Sapindus mukorossi (SM) demonstrated efficacy in dissolving pulp tissue but was not as effective as sodium hypochlorite (Hypo) which is the standard agent for root canal irrigation. SM to be used as an alternative to Hypo on clinical grounds needs further validation from research.

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).

Reliability of clinical examination methods for postoperative pain after primary root canal treatment

Background/purpose

Clinical test results may have lower reliability due to the varying range of test stimulation or patient subjectiveness. This study aimed to verify a reliable clinical test method by comparing pain intensity levels of a tooth at rest, during function, and after the clinical tests of percussion and chewing.

Materials and methods

A total of 36 asymptomatic necrotic teeth that required root canal treatment, one in each patient, were included. All treatment procedures were performed in a single visit by an experienced endodontist. Patients were asked to mark their pain levels on a vertical visual analog scale (VAS) while the relevant tooth was at rest and during function 24 h after the treatment. In addition, patients marked their pain levels after the clinical tests of percussion and chewing. Finally, the pain levels were compared using Pearson's correlation for the reliability of the test methods at a significance level of 95%.

Results

The postoperative pain levels measured during the clinical tests and functions were significantly higher than the pain levels at rest (P < 0.05). The pain levels after percussion tests were significantly higher than that during the function and chewing tests (P < 0.05). Pain intensity during the function was simulated with a higher correlation when using the chewing strip method rather than the percussion method.

Conclusion

The bite test using the chewing strips as a pain intensity assessment can mimic the actual postoperative pain experience, whereas the percussion test fails to provide the accuracy of this pain experience.

The effect of different concentrations and temperatures of sodium hypochlorite irrigation on pain intensity following endodontic treatment of mandibular molars with irreversible pulpitis: A randomized, double-blind clinical trial

OBJECTIVES

This study aimed to determine the severity of pain after endodontic treatment of mandibular molars with irreversible pulpitis following the use of sodium hypochlorite (NaOCl) at different temperatures and concentrations.

METHODS

In this randomized, controlled clinical trial, 72 patients with mandibular molars with irreversible pulpitis were randomly assigned to six groups. The teeth were anesthetized and the root canals were prepared. During the instrumentation, the root canals were irrigated with NaOCl solution at concentrations of 0.5% and 1% and temperatures of 2.5°C, 22°C, and 40°C, 2.5°C were achieved through cryotherapy. Assessment of pain was conducted before, immediately after, and 3, 24, 48, and 72 h after treatment. After obturation, the patients recorded their pain intensity at different time intervals on the visual analog scale (VAS) and reported the number of analgesics tablets they used. The frequency of analgesics tablets and their effect on pain sensation was recorded in the second part of the form. Repeated measures two-way analysis of variance test was used to compare the trend of pain changes over time between two intervals of time in each group. Friedman's nonparametric test was used to compare the intragroup mean score of pain over time and Kruskal-Wallis for comparing the intergroup mean score.

RESULTS

Changes in VAS pain scores of all the groups were significant over time (p < .001). Pain in all the groups decreased immediately after treatment and increased 3 h after treatment. There were no significant differences in pain ratings and the number of analgesics tablets used in the groups of NaOCl with different concentrations and temperatures over time.

CONCLUSIONS

Within the study's limitations, we concluded that there was no significant difference between concentrations of 0.5%, and 1% and temperatures of 2.5°C, 22°C, and 40°C in pain intensity following endodontic treatment of mandibular molars with irreversible pulpitis.

Prevalence of postoperative pain after endodontic treatment using low and high concentrations of sodium hypochlorite: a systematic review and meta-analysis

OBJECTIVES

To determine the prevalence of postoperative pain after endodontic treatment using low (LC) and high (HC) concentrations of sodium hypochlorite (NaOCl).

MATERIALS AND METHODS

Six databases and the grey literature were searched to identify randomized clinical trials that evaluated postoperative pain after endodontic treatment using NaOCl. NaOCl concentrations were dichotomized into 'LC' (0.5% to 3%) and 'HC' (≥ 5%) and a proportion meta-analysis was applied to determine the postoperative pain prevalence: overall and according to pain intensity and postoperative time. The prevalence of patients using pain control medication was also determined. A significance level of 5% and a random effect model were applied for data analysis. Between-study heterogeneity was assessed by I2 index. Risk of bias (RoB) was assessed using the Cochrane Risk-of-Bias 2.0 tool. The certainty of evidence was assessed using the GRADE approach.

RESULTS

Ten studies were included in the review and eight in the meta-analysis. The overall prevalence of postoperative pain was 45% in LC and 39% in HC. The prevalence of pain in LC and HC after 24 h was 25% and 40%, respectively. After 48 h, the prevalence decreased to 10% in LC and 25% in HC. 'Absent pain' was the most prevalent score. The prevalence of patients who used medication was 9% in LC and 15% in HC. Three studies were classified as 'high RoB', five as 'low RoB', and two as 'some concerns'. The certainty of evidence was very low.

CONCLUSIONS

The overall prevalence of postoperative pain after endodontic treatment using LC and HC of NaOCl was 45% and 39%, respectively.

CLINICAL RELEVANCE

Postoperative pain is common after endodontic treatment using NaOCl, but tends to decrease over time.

Postoperative pain after using passive ultrasonic irrigation and EasyClean device, irrigation activation techniques: a randomized clinical trial

INTRODUCTION

This randomized clinical trial aimed to compare postoperative pain after the use of two different irrigation activation techniques, passive ultrasonic irrigation and the EasyClean device.

METHODS

Sixty-six single-rooted teeth diagnosed with asymptomatic pulp necrosis and apical periodontitis were randomly assigned to two experimental groups (n=33), which differed in the irrigation activation technique. Postoperative pain levels were assessed after 24, 48, and 72 hours using a verbal rating scale; the ibuprofen intake amount was recorded at the same time intervals. Data were analyzed using Student's t-test, Mann-Whitney U and Fisher's exact tests, with a significance level of 5%.

RESULTS

Postoperative pain levels and analgesic intake frequency were not significantly different across the two irrigation activation techniques (P > .05). The frequencies obtained in relation to the prevalence of postoperative pain were 3.1-25.8% for all participants of the two studied groups.

CONCLUSION

The irrigation activation techniques of passive ultrasonic irrigation and the EasyClean device were found to be equivalent in terms of postoperative pain and analgesic intake.

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.

Effect of endodontic sealer on postoperative pain: a network meta-analysis

This systematic review and network meta-analysis aimed to answer the following focused research question: "Does the type of endodontic sealer affect the postoperative pain in patients who received endodontic treatment?" Different databases and grey literature were surveyed. Only one randomized controlled trial were included. The risk of bias in the studies was evaluated by using the Cochrane Collaboration's tool. A random-effects meta-analysis was conducted to compare the risk and intensity of postoperative pain. The quality of the body of evidence was assessed using the Grading of Recommendations Assessment, Development, and Evaluation approach. Out of 11,601 studies, 15 remained for qualitative analyses and 12 for meta-analysis. Seven studies were classified at high risk of bias, and 8 studies raised some concerns. No significant differences between the endodontic materials were observed in the direct comparisons, both in risk and in intensity of postoperative pain (pairwise comparisons with 2 studies: I² = 0%; p > 0.05 and 8 studies: I² = 23%; p > 0.05, respectively). The certainty of the evidence was graded as low or moderate. There was no difference in the risk and intensity of postoperative pain after filling with different endodontic sealers. Further systematic reviews should be conducted.

Trial Registration

PROSPERO Identifier: CRD42020215314.

Advances in the Role of Sodium Hypochlorite Irrigant in Chemical Preparation of Root Canal Treatment

Irrigation of root canal system is of great significance to the success of endodontic treatment, where sodium hypochlorite (NaOCl) is the most widely used irrigant in chemical preparation. NaOCl functions by eliminating bacterial biofilms and dissolving organic tissue, which may vary according to several factors such as the microbiology of root canal infection and the concentration of the irrigant. It has been proposed that the effectiveness of NaOCl could be enhanced via several methods, including heating the irrigant, applying in conjunction with certain reagents, or activating by agitation techniques. Despite its antibacterial and tissue-dissolving capacities, NaOCl should be used with caution to avoid detrimental effect due to its cytotoxicity and negative effect on dentin properties. In this narrative review, we discussed the factors that affect the properties of NaOCl, the methods to improve its efficacy, and the side effects that might occur in clinical practice.

Effect of EDDY and manual dynamic activation techniques on postoperative pain in non-surgical retreatment: a randomized controlled trial

BACKGROUND

During non-surgical retreatment process, the products such as dentin debris, root canal fillings, irrigation solutions, microorganisms and remaining pulp tissues can extrude to the apical area and can cause the postoperative pain and flare-up. Thus, the aim of this study was to evaluatethe effect of EDDY and manual dynamic activation (MDA) techniques on postoperative pain (PP) associated with retreatment.

METHODS

Ninety patients scheduled for retreatment were treated at a single visit. Non-vital mandibular premolar teeth diagnosed with asymptomatic apical periodontitis were included in this study. The patients were divided into two groups (n = 45) on the basis of the need for additional irrigation activation procedures (EDDY and MDA). The patients' post-treatment pain levels were asked to rate the intensity of their pain on a 10-point numerical rating scale (NRS) at the 12th, 24th, 48th, and 72nd h and 7 days.The data were analyzed using the chi-square and Wilcoxon signed-rank test was used for within-group comparisons and Mann Whitney U test was used to compare the groups by time period.

RESULTS

The difference in postoperative pain intensity between two groups was statistically significant at 12, 24, 48, and 72 h (p < 0.05). There was no significant difference at 7 days. Moreover, no statistically significant difference was found between the two groups in terms of gender and analgesic medication intake (p > 0.05). Pain intensity after the treatment was lesser in the MDA groupthanin the EDDY group at 12, 24, 48, and 72 h.

CONCLUSION

This study could lead us to conclude that the two activation systems can be used during endodontic retreatment with no difference at PP 7 days later. However, a comparison of the groups indicated that the EDDY resulted in significantly more PP at 12, 24, 48, and 72 h. Trial registration ClinicalTrials.gov Identifier: NCT04726670.

Postoperative pain after primary molar pulpectomy using rotary or reciprocating single files: A superior, parallel, randomized clinical trial

AIM

To compare postoperative pain intensity between two single-file systems with different kinetics (the OneShape file with continuous rotation vs. the WaveOne Gold file with reciprocation movement) after primary molar pulpectomy.

DESIGN

This superiority, parallel, randomized clinical trial included 164 healthy children aged 6 to 8 years with asymptomatic, necrotic, maxillary primary second molars due to caries. An equal number of children were assigned to the two groups. The teeth of children in Group 1 were instrumented with the OneShape rotary system (Micro-Mega), whereas teeth of children in Group 2 were instrumented with the WaveOne Gold reciprocating system (Dentsply Maillefer). Postoperative pain intensity was assessed using a 4-point pain scale at 6, 12, 24, 48 and 72 h and 1 week after treatment. The parent of each participant received 6 flashcards that included four faces and a word describing each face. A chi-square test was used to compare postoperative pain intensity. The level of significance was set to 5%.

RESULTS

Over the follow-up period, no significant difference in postoperative pain intensity was found between the two groups (p > .05). Although the absolute risk reduction maximum limit of 95% CI equal or exceeded the predetermined proportional difference of 0.15, pain intensity was inconclusive at 6, 24, and 48 hours denoting that the superiority of the OneShape single-file over the WaveOne Gold single-file could not be declared.

CONCLUSIONS

Postoperative pain intensity associated with a rotary vs. reciprocating file system was nearly similar.

Effects of concentration of sodium hypochlorite as an endodontic irrigant on the mechanical and structural properties of root dentine: A laboratory study

AIM

The use of high-concentration sodium hypochlorite (NaOCl) as an endodontic irrigant remains controversial because of its potential impact on the fracture strength of endodontically-treated teeth. This study evaluated the effects of using different NaOCl concentrations, with 2-min-ethylenediaminetetraacetic acid (EDTA) as the final active irrigant, on the biomechanical and structural properties of root dentine.

METHODOLOGY

A new test method, which is more clinically relevant, was utilized to calculate the fracture strength of root dentine. Bovine incisors were used to obtain root dentine discs. The root canals were enlarged to mean diameter of 2.90 mm with a taper of 0.06. The resulting discs were divided into 5 groups (n=20) and treated with different concentrations of NaOCl (5.25%, 2.5%, and 1.3%) for 30 min plus 17% EDTA for 2 min. The discs were then loaded to fracture by a steel rod with the same taper through the central hole. The fractured specimens were examined by scanning electron microscopy to evaluate changes in the dimensions of the remaining intertubular dentine and the tubular radius. Micro-hardness was also measured with a Knoop diamond indenter along a radius to determine the depth of dentine eroded by the irrigation. Results were analyzed by one-way ANOVA and the Tukey test. The level of significance was set at α = 0.05.

RESULTS

The damage by NaOCl increased with its concentration. 5.25% NaOCl greatly reduced the fracture strength of root dentine from 172.10±30.13 MPa to 114.58±26.74 MPa. The corresponding reduction in micro-hardness at the root canal wall was 34.1%. The damages reached a depth of up to 400 μm (p < 0.05). Structural changes involved degradation of the intratubular wall leading to enlarged dentinal tubules and the loss of intertubular dentine. Changes in the microstructural parameters showed positive linear relationships with the fracture strength.

CONCLUSIONS

With the adjunctive use of EDTA, NaOCl caused destruction to the intratubular surface near the root canal and, consequently, reduced the root dentine's mechanical strength. The higher the concentration of NaOCl, the greater the effect. Therefore, endodontists should avoid using overly high concentration of NaOCl for irrigation to prevent potential root fracture in endodontically-treated teeth.

Postoperative Pain Following Root Canal Instrumentation Using ProTaper Next or Reciproc in Asymptomatic Molars: A Randomized Controlled Single-Blind Clinical Trial

Aim: The development of postoperative pain following root canal instrumentation may impair patient’s comfort and undermine their trust in the dentist. This study assessed the effect of root canal instrumentation techniques (rotary (PTN; ProTaper Next®) and reciprocating (R; Reciproc®)) on the postoperative pain intensity (primary outcome) and tenderness on biting (secondary outcome) of patients’ asymptomatic molars. Methodology: This study protocol was registered with ReBec-WHO (U1111-1182-2800). From a pool of 112 patients evaluated for eligibility (healthy adults (≤18 years old)), with a single asymptomatic molar (maxillary or mandibular) indicated for root canal treatment, diagnosed with asymptomatic irreversible pulpitis (including chronic hyperplastic pulpitis), 75 were randomly allocated in similar proportions to receive the intervention (two-appointment root canal therapy) in either the PTN or R group. The allocated procedures were performed using standardized protocols. Participants (blinded to the instrumentation technique) rated their pain intensity at 6, 12 and 24 h and from day 2 to day 7 following the root canal instrumentation appointment using a VAS and an NRS; the ibuprofen tablets taken and the presence of tenderness on biting were recorded. The instrumentation time was registered. Univariate and multivariate statistics measured the effect of independent variables on the outcomes. Results: From the 75 patients allocated, 8 patients (4 from each group) were lost; in total, 33 patients were analyzed in the PTN group and 34 in the R group. The frequencies of postoperative pain (p > 0.05) and tenderness on biting (p > 0.05) were similar between groups. The medication intake (mean of 1.31 tablets) and the time of instrumentation (approximately 11 min) were similar between groups. Conclusion: ProTaper Next and Reciproc® caused a slight risk of tenderness on biting and contributed to similar self-reported postoperative pain (low intensity) up to 7 days following root canal shaping.

Effect of Qmix 2in1, chlorhexidine gluconate, and ethylenediaminetetraacetic acid on postoperative pain after root canal treatment: A double-blind randomized clinical trial

Background. This study aimed to investigate the effects of different final irrigation solutions on postoperative pain following root canal treatment.

Methods. Eighty-nine nonvital premolar and molar teeth with periapical lesions (PAI: 3‒4) without any clinical symptoms were included. The patients were randomly assigned to three groups according to the final irrigation solutions used: G1: 2 mL of Qmix (n=29), G2: 2 mL of 17% ethylenediaminetetraacetic acid (EDTA) (n=30), and G3: 2 mL of 2% chlorhexidine gluconate (CHX) (n=30). All the patients were prescribed 100 mg of flurbiprofen to use as needed for pain. The patients were asked to rate their pain status according to the verbal rating scale at 12, 24, 48, and 72 hours, and one week. The data were analyzed using Pearson’s chi-squared test, Fisher’s exact test, and chi-squared analysis with Monte Carlo simulation. The significance level was set at P≤0.05.

Results. No significant differences were observed in postoperative pain rates at 12, 48, and 72 hours and one week (P>0.05). However, in the Qmix group, a significantly lower pain level was observed at 24 hours with EDTA and CHX (P=0.019). The rate of mild pain in the EDTA group at 72 hours (18.8%) was significantly higher in premolar teeth than in molar teeth (P=0.012). The moderate pain level in the EDTA group at 12 hours was significantly higher in those>60 years of age (P=0.008).

Conclusion. The use of Qmix as an irrigation solution resulted in lower postoperative pain levels at 24 hours compared to other solutions. Therefore, Qmix can be considered a proper final irrigation solution in endodontic treatment regarding postoperative pain.

Present status and future directions - irrigants and irrigation methods

Irrigation is considered the primary means of cleaning and disinfection of the root canal system. The purpose of this review was to set the framework for the obstacles that irrigation needs to overcome, to critically appraise currently used irrigants and irrigation methods, to highlight knowledge gaps and methodological limitations in the available studies and to provide directions for future developments. Organization of bacteria in biofilms located in anatomic intricacies of the root canal system and the difficulty to eliminate them is the main challenge for irrigants. Sodium hypochlorite remains the primary irrigant of choice, but it needs to be supplemented by a chelator. Delivery of the irrigants using a syringe and needle and activation by an ultrasonic file are the most popular irrigation methods. There is no evidence that any adjunct irrigation method, including ultrasonic activation, can improve the long‐term outcome of root canal treatment beyond what can be achieved by instrumentation and syringe irrigation. It is necessary to redefine the research priorities in this field and investigate in greater depth the penetration of the irrigants, their effect on the biofilm and the long‐term treatment outcome. New studies must also focus on clinically relevant comparisons, avoid methodological flaws and have sufficiently large sample sizes to reach reliable conclusions. Future multidisciplinary efforts combining the knowledge from basic sciences such as Chemistry, Microbiology and Fluid Dynamics may lead to more effective antimicrobials and improved activation methods to bring them closer to the residual biofilm in the root canal system.

Postoperative pain after SWEEPS, PIPS, sonic and ultrasonic-assisted irrigation activation techniques: a randomized clinical trial

To investigate the efficacy of a new laser irrigation activation system [shock wave-enhanced emission photo-acoustic streaming (SWEEPS)] in terms of postoperative pain after primary root canal treatment compared with other techniques, namely photon-induced photo-acoustic streaming (PIPS), sonic system with EDDY, passive ultrasonic system (PUI), and manual dynamic activation (MDA). Two hundred patients with symptomatic irreversible pulpitis in mandibular premolar teeth were enrolled and randomly allocated to five different irrigation activation groups (n = 40) after chemo-mechanical root canal preparation. For irrigation activation, the SWEEPS and PIPS tips were attached to the Er-YAG laser system in the respective groups, while the Irrisafe tip was used in the PUI group and the EDDY tip in the sonic group. In the MDA group, irrigation was agitated with the master gutta-percha cone. At postoperative hours 8, 24, and 48 and on day 7, pain intensity was evaluated using the 10-mm Visual Analog Scale (VAS) and analgesic intake was recorded. The Kruskal-Wallis test was used to analyze the VAS scores, and pain prevalence and analgesic intake were examined with the Pearson's chi-square test at the 5% significance level. The PIPS and SWEEPS groups had the lowest level and prevalence of pain when compared to the remaining groups (P < 0.001). The PUI, sonic and MDA groups did not differ in terms of pain scores at hours 8 and 48 (P > 0.05). On day 7, the highest score and pain prevalence were recorded in the MDA group (P < 0.001). There was no difference between the groups in terms of analgesic intake (P > 0.05). Laser-activated irrigation systems provided lower postoperative pain scores and levels compared to the other activation systems. The MDA group had the highest pain scores and incidence at the end of the seventh day.

Update on Endodontic, Restorative, and Prosthodontic Therapy

Endodontic therapy is intended to preserve the function of mature teeth with irreversible pulpitis or pulp necrosis or to maintain the vitality of endodontically compromised immature teeth. Standard root canal therapy and vital pulp therapy are 2 mainstays of endodontic treatment. Recent knowledge has improved the outcomes of endodontic treatment with newer materials, such as mineral trioxide aggregate. Composite or prosthodontic crown restoration is also a critical key to success.

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.

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.

Postoperative pain after endodontic treatment of necrotic teeth with large intentional foraminal enlargement

Objectives

To evaluate postoperative pain after endodontic treatment of necrotic teeth using large intentional foraminal enlargement (LIFE).

Materials and Methods

The sample included 60 asymptomatic necrotic teeth (with or without chronic apical periodontitis), and a periodontal probing depth of 3 mm, previously accessed and referred to perform endodontic treatment. After previous procedures, the position and approximate size of the apical foramen (AF) were determined by using an apex locator and K flexo-files, respectively. The chemomechanical preparation was performed with Profile 04 files 2 mm beyond the AF to achieve the LIFE, using 2.5 mL of 2.5% NaOCl at each file change. The filling was performed by Tagger's hybrid technique and EndoFill sealer. Phone calls were made to all the patients at 24, 48 and 72 hours after treatment, to classify postoperative pain. Statistical analysis was performed by different tests with a significance level of 5%.

Results

Age, gender, periradicular status and tooth type did not influence postoperative pain (p > 0.05). Only 1 patient (1.66%) reported severe pain after 72 hours. Moderate pain was reported by 7, 4 and 3 patients after 24, 48 and 72 hours, respectively (p = 0.0001). However, paired analyses showed a statistically significant difference only between 24 and 72 hours (p = 0.04). Sealer extrusion did not influence the postoperative pain (p > 0.05).

Conclusions

Acute or moderate postoperative pain was uncommon after endodontic treatment of necrotic teeth with LIFE.

Trial Registration

The Brazilian Clinical Trials Registry Identifier: RBR-3r967t

The effect of solution and gel forms of sodium hypochlorite on postoperative pain: a randomized clinical trial

Objectives

The aim of this study is to evaluate the effect of using gel and solution forms of NaOCI during the chemomechanical preparation of the root canals on postoperative pain at different time intervals.

Methodology

114 patients with mandibular molar teeth and symptomatic irreversible pulpitis were included in the study. All patients were divided into two groups based on the irrigant used during root canal preparation (n=57): Group 1, 5.25% NaOCI, Group 2, 5.25% NaOCI gel. All groups were filled with gutta-percha and AH Plus root canal sealer using single-cone technique. VAS scale (1-10) was used for postoperative pain assessment. After endodontic treatment, all patients were asked to record their postoperative pain levels at the 6th, 24th, 48th, 72nd hours, and 1 week later. The data were analyzed using Chi-Squared, Independent Samples T, Cochran Q and Friedman tests.

Results

Statistically significant difference was not found between the distributions of pain levels at different times according to the groups (p>0.050). A statistically significant difference was observed between the distributions of pain levels measured at different times in the solution group (p<0.001). A statistically significant difference was found between the distributions of pain levels measured at different times in the gel group (p<0.001). In both groups, highest postoperative pain levels occurred in the first 6 hours. Pain levels of the gel group as 38,5% mild, 17.3% moderate, 5.8% severe and pain levels of the solution group were obtained as 46.2% mild, 26.9% moderate, 9.6% severe at the 6th hour.

Conclusions

The use of the gel form of NaOCI during the chemomechanical preparation of the root canals showed similar postoperative pain when compared to the solution form.

Influence of occlusal reduction on pain after endodontic treatment: a systematic review and meta-analysis

The purpose of this systematic review was to analyze the influence of occlusal reduction on the postoperative pain levels after endodontic treatment (instrumentation and obturation of the root canal system). This review followed the PRISMA statement and was registered at PROSPERO (CRD42018107918). Two independent reviewers searched the Lilacs, Cochrane Library, PubMed (Medline), Web of Science, Scopus, Scielo, and ScienceDirect for articles published until April 2021. The research question was, "Does occlusal reduction decrease postoperative pain in endodontically treated teeth?". Only randomized clinical trials were included. The RevMan 5 program was used for meta-analysis, calculating the relative risk (RR) and 95% confidence interval (CI) of the dichotomous outcome (presence or absence of pain). The search strategies retrieved 4114 studies. Twelve studies were included for qualitative analysis and nine for quantitative analysis. The meta-analysis results did not reveal a significant difference in the reduction of postoperative pain levels for endodontic instrumentation at 6, 12, 24, 48 h and for endodontic obturation at 6 or 12 h after occlusal reduction. According to the GRADE tool, the analyzed outcome was classified as having a moderate level of certainty. It is concluded that occlusal reduction does not interfere with postoperative pain levels after endodontic treatment.

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.

Calcium Silicate-Based Sealers Do Not Reduce the Risk and Intensity of Postoperative Pain after Root Canal Treatment when Compared with Epoxy Resin-Based Sealers: A Systematic Review and Meta-Analysis

This review aims to evaluate whether root canal obturation with calcium silicate-based (CSB) sealers reduces the risk and intensity of endodontic postoperative pain when compared to epoxy resin-based (ERB) sealers. The review was registered at PROSPERO (CRD42020169255). Two independent reviewers conducted an electronic search in PubMed, Scopus, EMBASE, Web of Science, Cochrane Library and LILACS until November 2020 and included only randomized clinical trials with adult health participants undergoing root canal treatment. After selection, the JBI Critical Appraisal tool was used to assess the risk of bias. A fixed-effect meta-analysis was performed to summarize the results of pain risk and pain intensity at time intervals of 24 and 48 hours. Finally, the certainty of evidence was assessed using the GRADE approach. The search resulted in 1,206 records, of which five studies (n = 421 patients) met the eligibility criteria and presented moderate to low risk of bias. There was no significant difference between groups in the risk of pain in the first 24 hours (relative risk or RR = 0.83, 95% confidence interval or CI: 0.60, 1.16, I 2 =) or 48 hours (RR = 0.56, 95% CI: 0.26, 1.21, I 2 =). Silicate-based sealers led to lower pain intensity only at 48 hours (mean and standard deviation = 0.37, 95% CI: 0.69, 0.05). All analyses revealed low heterogeneity (I 2 < 25%). The evidence presented moderate level of certainty. Currently available evidence has shown that there is no difference between CSB and ERB sealers in the risk or intensity of postoperative pain.

Postoperative Pain after Endodontic Treatment under Irrigation with 8.25% Sodium Hypochlorite and Other Solutions: A Randomized Clinical Trial

INTRODUCTION

The aim of this study was to evaluate the postoperative pain in patients after endodontic treatment using 8.25% sodium hypochlorite (NaOCl) compared with other concentrations and 2% chlorhexidine (CHX).

METHODS

In this double-blind randomized trial, 180 patients were evaluated who underwent a single session of endodontic treatment under irrigation with 2.5%, 5.25%, or 8.25% NaOCl or 2% CHX solutions. The presence of postoperative pain was assessed 24, 48, and 72 hours after treatment and recorded using the visual analog scale (VAS). A descriptive analysis, logistic regression, and Wald test were performed.

RESULTS

Altogether 169 patients participated, of whom 107 were women, and the mean age was 38.1 ± 14.4 years. No significant differences occurred between the irrigants and the pain outcomes, not even for the use of postoperative pain medication and responses to VAS (P > .05). In the multivariate model including irrigants, after 24 hours or at any time, a significant difference (P < .05) remained in preparation time ≥10 minutes and the presence of overfilling. Also, in relation to the VAS, the overfilling presented significantly different results (P < .05).

CONCLUSIONS

There was no significant difference in the presence of postoperative pain between the 8.25% NaOCl and the other irrigation solutions. However, the extended preparation time and the overfilling material were responsible for the increase of postoperative pain.

Final Endodontic Irrigation with 2% Peracetic Acid: Antimicrobial Activity and Cytotoxicity

OBJECTIVE

 The aim of present study was to assess the cytotoxicity and antimicrobial efficacy of 2% peracetic acid (PAA) compared with 5.25% sodium hypochlorite (NaOCl) and 2% chlorhexidine (CHX).

MATERIAL AND METHODS

 For the cytotoxicity test, 100 µl of the tested solutions were added in 12 wells with ECV 304 endothelial cells in each group: NaOCl, CHX, and PAA, in addition to the control group. Each solution was evaluated after 24 hours of contact in four dilutions: 0.2, 0.1, 0.05 and 0.025 through mitochondrial function using MTT colorimetric assay. In the antimicrobial evaluation, 40 dentin blocks 5 mm in length and 0.2 g in weight were incubated with 400 µl of Enterococcus faecalis suspension for 21 days at 37°C. The contaminated samples were divided into three experimental groups within 5 minutes of contact: NaOCl group, CHX group, PAA group, as well as the positive control group. The specimens received treatment and were transferred to a tube with saline for serial dilution of the solution and seeding for isolation and colony forming unit (CFU) count.

STATISTICAL ANALYSIS

 The results obtained were expressed as mean (A570 nm) ± standard deviation (SD) and in a multiple linear regression model and multiple comparisons conducted.

RESULTS

 The antimicrobial evaluation revealed that the NaOCl and CHX groups showed a statistically significant difference compared with the control group (p < 0.001), while the PAA reduced only the CFU growth. It can be concluded that, among the agents tested, PAA expressed greater cell viability, followed by CHX and NaOCl. However, it did not show greater antimicrobial activity in vitro in the mature biofilm of Enterococcus faecalis.

Impact of root canal treatment on high-sensitivity C-reactive protein levels in systemically healthy adults with apical periodontitis - a preliminary prospective, longitudinal interventional study

AIM

To assess the influence of root canal treatment on serum high-sensitivity C-reactive protein (hsCRP) levels in systemically healthy human adults.

METHODOLOGY

Fifteen individuals aged 20-40 years diagnosed with apical periodontitis [Periapical Index (PAI) score ≥3] who were otherwise healthy took part in this prospective interventional study. Patients with moderate to severe periodontitis, systemic diseases and traditional cardiac risk factors (hypertension, diabetes, dyslipidemia and smoking) were excluded. Root canal treatment was completed in two visits with an inter-appointment calcium hydroxide intracanal medicament. After 6 months, healing of apical periodontitis was evaluated clinically and radiographically, and serum hsCRP levels were recorded. A paired sample T-test was used to compare the mean hsCRP values between the pre- and post-treatment groups. The Mann-Whitney U test was used to compare hsCRP values between patients with PAI scores of 3 and 4, and the Wilcoxon signed-rank test was used to compare pre- and postoperative PAI scores.

RESULTS

The mean preoperative baseline serum hsCRP level was 2.88 ± 1.06 mg L^-1 which can be associated with a moderate risk for cardiovascular disease (CVD). Based on the preoperative hsCRP levels, eight of the 15 patients were categorized as high risk (hsCRP > 3 mg L^-1 ) and the other seven as medium risk (hsCRP 1-3 mg L^-1 ) for CVD. The mean preoperative hsCRP value of patients with a PAI score of 3 was 2.88 ± 1.19 mg L^-1 , and the mean preoperative hsCRP of patients with a PAI score of 4 was 2.87 ± 0.15 mg L^-1 , which was not significantly different (P = 0.942). Six months after root canal treatment, the mean PAI score had significantly reduced from 3.2 ± 0.42 to 1.4 ± 0.69 (P = 0.003). The PAI score had reduced to ≤2 in 87% of the patients, and the mean serum hsCRP levels had significantly reduced to 1.34 ± 0.52 mg L^-1 (P < 0.001). Ten of the 15 patients had a reduction in their CVD risk status.

CONCLUSIONS

This study suggests that root canal treatment can reduce serum hsCRP levels in systemically healthy individuals with apical periodontitis.

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.

Influence of glide path kinematics during endodontic treatment on the occurrence and intensity of intraoperative and postoperative pain: a systematic review of randomized clinical trials

Background

Preliminary canal enlargement (glide path preparation) may play a significant role in the development of pain. The aim of this systematic review of randomized clinical trials was to assess the influence of glide path kinematics during endodontic treatment on the occurrence and intensity of intraoperative and postoperative pain.

Methods

A search was performed in June 2019 in six electronic databases (PubMed, Scopus, LILACS, SciELO, Embase and Web of Science) and two grey literature databases (OpenGrey and OpenThesis). The bibliographic references of the eligible articles were also hand-searched. The included clinical studies assessed the occurrence and intensity of intraoperative and/or postoperative pain after root canal preparation without glide path preparation (WGP) or with glide path preparation using manual (M-GP), continuous rotary (CR-GP), or reciprocating (R-GP) instruments. The primary outcome was the occurrence and intensity of intraoperative and postoperative pain, while analgesic consumption was the secondary outcome. The full texts of the eligible studies were analyzed by two reviewers who performed calibration exercises to verify the risk of bias and quality of the individual studies using the Joanna Briggs Institute Critical Appraisal tool.

Results

From 1283 identified articles, only six studies were included in the qualitative analysis of the results, with a total sample of 884 patients/teeth. Three studies presented a high risk of bias, while three studies presented a moderate risk. Two studies reported that CR-GP causes lower pain levels than M-GP and WGP, and three studies showed no differences between CR-GP and R-GP. Regarding analgesic consumption, two studies found no differences among glide path kinematics, and one study reported lower consumption for CR-GP than for M-GP. Because of the limited number of studies and methodological differences, no statistical analyses were performed for the glide path kinematics comparisons.

Conclusions

Compelling evidence indicating a significantly different occurrence and intensity of pain among glide path kinematics is lacking.

The systematic review protocol was registered in the PROSPERO database [CRD42020139989].

Post-treatment endodontic pain following occlusal reduction in mandibular posterior teeth with symptomatic irreversible pulpitis and sensitivity to percussion: a single-centre randomized controlled trial

AIM

This 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.

METHODOLOGY

Three 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.

RESULTS

Occlusal 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).

CONCLUSIONS

Occlusal 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.

Novel Approaches to Detect and Treat Biofilms within the Root Canals of Teeth: A Review

Biofilms located within the root canals of teeth are a unique and pressing concern in dentistry and in medical microbiology. These multispecies biofilms, which include fungi as well as bacteria, form in a protected site with low shear stress and low oxygen tension. Systemic antibiotics are of limited value because of the lack of blood flow of the site, and issues with innate and acquired resistance. Physical disruption using hand or rotary powered instruments does not reach all locations in the root canal system where biofilms are present. Alternative strategies including agitated irrigation fluids, continuous chelation, materials with highly alkaline pH, and antimicrobial nanoparticles are being explored to meet the challenge. Detection and quantification of biofilms using fluorescence-based optical methods could provide an indication of successful biofilm removal and an endpoint for physical and chemical treatments.