Genetic Variants in Cyclooxygenase-2 Contribute to Post-treatment Pain among Endodontic Patients

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.

Association between single-nucleotide polymorphisms in serotonin receptor 2A and melatonin receptor 1A genes and pain after root canal treatment

AIM

This study aimed to investigate whether single-nucleotide polymorphisms (SNPs) in the genes encoding 5-HTR2A (5-Hydroxytryptamine (serotonin) receptor 2A) and MTNR1A (melatonin receptor 1A) may contribute to postoperative pain perception after root canal treatment. We hypothesised that SNPs in HTR2A and MTNR1A genes were associated with postoperative pain after root canal treatment.

METHODOLOGY

This genetic cohort study enrolled patients with single-rooted teeth diagnosed with pulp necrosis and asymptomatic apical periodontitis before root canal treatment. Root canal treatment was performed in one session using a standardized protocol. Postoperative pain and tenderness were assessed using a visual analogue scale (recorded every day for 7 days and on the 14th and 30th days after root canal treatment). Genomic DNA was extracted from saliva and used to genotype the SNPs in HTR2A (rs4941573 and rs6313) and MTNR1A (rs6553010, rs6847693 and rs13140012) using real-time polymerase chain reaction. Genotypes were compared using univariate and multivariate Poisson regression with generalized estimating equations (p < .05).

RESULTS

In total, 108 patients were enrolled in this study. The SNPs rs6553010 (MTNR1A), rs4941573 and rs6313 (HTR2A) were associated with an increased risk of developing pain after root canal treatment (p < .05).

CONCLUSIONS

This study suggests that SNPs in HTR2A and MTNR1A influence pain response after root canal treatment.

An in vitro anti-inflammatory effect of Thai propolis in human dental pulp cells

OBJECTIVE

To explore the potential for development of Thai propolis extract as a pulp capping agent to suppress pulpal inflammation from dental pulp infections. This study aimed to examine the anti-inflammatory effect of the propolis extract on the arachidonic acid pathway, activated by interleukin (IL)-1β, in cultured human dental pulp cells.

METHODOLOGY

Dental pulp cells, isolated from three freshly extracted third molars, were first characterized for their mesenchymal origin and treated with 10 ng/ml of IL-1β in the presence or absence of non-toxic concentrations of the extract from 0.08 to 1.25 mg/ml, as determined by the PrestoBlue cytotoxic assay. Total RNA was harvested and analyzed for mRNA expressions of 5-lipoxygenase (5-LOX) and cyclooxygenase-2 (COX-2). Western blot hybridization was performed to investigate COX-2 protein expression. Culture supernatants were assayed for released prostaglandin E2 levels. Immunofluorescence was conducted to determine involvement of nuclear factor-kappaB (NF-kB) in the inhibitory effect of the extract.

RESULTS

Stimulation of the pulp cells with IL-1β resulted in the activation of arachidonic acid metabolism via COX-2, but not 5-LOX. Incubation with various non-toxic concentrations of the propolis extract significantly inhibited upregulated COX-2 mRNA and protein expressions upon treatment with IL-1β (p<0.05), resulting in a significant decrease in elevated PGE2 levels (p<0.05). Nuclear translocation of the p50 and the p65 subunits of NF-kB upon treatment with IL-1β was also blocked by incubation with the extract.

CONCLUSIONS

Upregulated COX-2 expression and enhanced PGE2 synthesis upon treatment with IL-1β in human dental pulp cells were suppressed by incubation with non-toxic doses of Thai propolis extract via involvement of the NF-kB activation. This extract could be therapeutically used as a pulp capping material due to its anti-inflammatory properties.

Association between polymorphisms in catechol-O-methyl transferase, opioid receptor Mu 1 and serotonin receptor genes with postoperative pain following root canal treatment

AIM

To evaluate the effect of single nucleotide polymorphisms in the COMT, OPRM1, 5HT1A, 5HT2A and 5HTR3B genes on the intensity of postoperative pain following root canal treatment.

METHODOLOGY

Ninety-five patients with mandibular and maxillary molar teeth diagnosed with symptomatic apical periodontitis and a level of preoperative pain greater than 50 on a 100 mm visual analogue scale (VAS) were included. Salivary DNA was collected from the participants and stored in Eppendorf tubes at -80 °C. Preoperative percussion pain values were recorded before the root canal treatment procedures. After completion of root canal treatment, the participants were given instructions to record their postoperative pain intensity levels at 24, 48 and 72 h, 5 days and 1 week after treatment, using the VAS. A second visit for the patients after seven days was planned to record their intensity levels of percussion pain on VAS. The percussion test was performed by tapping on the occlusal surface of the tooth with a blunt instrument. A QIAamp DNA Mini Kit was used to isolate DNA from saliva, and SNP Genotyping Analysis software version 1 was used to analyse the genotypes by calculating FAM and HEX signals. The Kruskal-Wallis and Mann-Whitney U-tests were used to evaluate pain intensity values amongst the genotypes, alleles, haplotypes and allele combinations. Nominal data (gender, intake and tooth number) were analysed using a Chi-square test. Bonferroni correction was performed. Thus, the significance level was set at 1.6% (P = 0.016), 2.5% (P = 0.025) and 1.25% (P = 0.0125) for genotype, allele and haplotype comparisons, respectively.

RESULTS

There was no significant difference amongst the genotypes and alleles in terms of pre- and postoperative pain intensity. There was no significant difference amongst the haplotypes formed for the COMT gene in terms of pain intensity. Additionally, there was no significant association between the allelic combination formed for 5HT1A + 5HT2A genes and the intensity of postoperative pain.

CONCLUSION

The findings indicate that none of the evaluated SNPs for COMT, OPRM1, 5HT1A, 5HT2A and 5HTR3B genes were associated with the intensity of postoperative pain.

A bioinformatics investigation into the pharmacological mechanisms of the effect of Fufang Danshen on pain based on methodologies of network pharmacology

Fufang Danshen (FFDS), a Chinese medicine formula widely used in the clinic, has proven therapeutic effects on pain relief. However, the mechanisms of these effects have not been elucidated. Here, we performed a systematic analysis to discover the mechanisms of FFDS in attenuating pain to gain a better understanding of FFDS in the treatment of other diseases accompanied by pain. Relevance analysis showed that Salvia miltiorrhizae was the best studied herb in FFDS. Most compounds in FFDS have good bioavailability, and we collected 223 targets for 35 compounds in FFDS. These targets were significantly enriched in many pathways related to pain and can be classified as signal transduction, endocrine system, nervous system and lipid metabolism. We compared Salvia miltiorrhizae and Panax notoginseng and found that they can significantly affect different pathways. Moreover, ten pain disease proteins and 45 therapeutic targets can be directly targeted by FFDS. All 45 therapeutic targets have direct or indirect connections with pain disease proteins. Forty-six pain disease proteins can be indirectly affected by FFDS, especially through heat shock cognate 71 kDa protein (HSPA8) and transcription factor AP-1 (JUN). A total of 109 targets of FFDS were identified as significant targets.

The Effect of Different Combinations of Calcium Hydroxide as Intra-Canal Medicament on Endodontic Pain: A Randomized Clinical Trial Study

Introduction

After treating the tooth root canal, pain is one of the problems that many patients are facing. In order to reduce pain, and regarding the advice of treating necrotic teeth during several sessions, intra-canal medicaments can be used between sessions. The purpose of this study is to compare pain relieving effect of calcium hydroxide combined with three solutions of normal saline, chlorhexidine 2% and dexamethasone.

Materials and methods

This triple blind randomized clinical trial was performed on 90 necrotic molars and premolars. The patients were classified in three medicaments' groups including mixture of calcium hydroxide and normal saline (G1), chlorhexidine 2% (G2) or dexamethasone (G3) that were placed in the canal during the first treatment session. The patients were provided with a Heft-Parker Visual Analog Scale form to record their pain in different intervals of 4, 24, 48, 72 and 96 h after cleaning and shaping the root canal. Data analysis was carried out using the Chi-Square, one-way ANOVA and Repeated Measure tests.

Results

No significant difference was observed in the mean pain of the groups after 4 h (P>0.05). However, a significant difference was found between G1 and G3 in the mean pain from day 1 to 72 h after treatment. The mean pain was less in dexamethasone (G3) group (P<0.05), but the difference was not statistically significant at 96 h after treatment (P>0.05). No significant difference was found between "G2-G1" and "G2-G3" groups at different time intervals (P>0.05).

Conclusion

The mixture of calcium hydroxide and dexamethasone compared to calcium hydroxide and normal saline in short and medium time had a significant effect on reducing pain after cleaning and shaping the root canal. It seems that the mixture of calcium hydroxide and dexamethasone can be considered as an effective medicament on reducing pain during root canal treatment sessions.

Effect of Corticosteroids on Pain Relief Following Root Canal Treatment: A Systematic Review

INTRODUCTION

Post-operative pain and flare-up may occur in up to 58% of patients following root canal treatment. The aim was to conduct a systematic review and a possible meta-analysis to determine the effect of glucocorticosteroid (GCS) on pain following root canal treatment.

METHODS AND MATERIALS

Scopus, MEDLINE and CENTRAL databases were searched up to 30th January 2017 with broad key words. In addition, the reference lists in eligible papers and text books were hand-searched. Assessment of the eligibility of papers and data extraction were performed by two independent reviewers.

RESULTS

Of 9891 articles, 18 were recruited as eligible papers. Most of these papers showed pain reducing effect of GCS on post-endodontic pain. Because of wide heterogeneity among the recruited papers, it was not possible to perform meta-analysis.

CONCLUSION

Based on the results of this systematic review, there is a vast heterogeneity amongst articles regarding the use of GCS and their effect on post-operative pain after endodontic treatment. Further investigations with similar methods and materials are needed before meta-analysis on the effect of GCS on post-operative pain following root canal treatment can be performed.