Reduction of viableEnterococcus faecalisin human radicular dentin treated with 1% cetrimide and conventional intracanal medicaments

The Effect of Glycyrrhizin on the Viability and Proliferation of Dental Pulp Stem Cells Compared to Intracanal Medicaments

AIM

To study the effect of glycyrrhizin (GA) on the viability and proliferation of dental pulp stem cells (DPSCs) compared with intracanal medicaments.

MATERIALS AND METHODS

Third molars of an adult donor were used to obtain the DPSCs. Flow cytometry was utilized to conduct phenotypic analysis for DPSCs. The methyl-thiazol tetrazolium (MTT) test was used to detect the cell viability. Cell proliferation assay was conducted at distinct time intervals: 3, 5, and 7 days.

RESULTS

The flow cytometry analysis verified the positive expression of mesenchymal cell surface antigen molecules (CD73, CD90, and CD105) and the absence of hematological markers (CD14, CD34, and CD45) in the DPSCs. The cells that treated with concentrations more than 0.5 mg/mL of Ca(OH2) and triple antibiotic paste (TAP) gave significant decrease in viability in comparison to the untreated cells (p < 0.05). Also, the cells treated with concentrations 50 and 25 µM of GA showed no significant difference compared with the untreated cells (p > 0.05), while concentrations 12.5 and 6.25 µM expressed a significant increase in viability compared with the untreated cells (p < 0.05). At 7 days, cells treated with the three different concentrations of GA (12.5, 25, and 50 µM) demonstrated a significant increase in cell density compared with Ca(OH)2 and TAP-treated cells (p < 0.05).

CONCLUSION

Based upon the potential of GA on DPSCs proliferation compared with Ca(OH)2 and TAP, It is conceivable to acknowledge that GA could be used as an intracanal medicaments for revascularization process of necrotic immature teeth.

CLINICAL SIGNIFICANCE

This study emphasizes the significance of assessing alternative root canal medicaments and their impact on the proliferation and viability of DPSCs. The results regarding GA, specifically its impact on the viability and growth of DPSCs, provide essential understanding for its potential application as an intracanal medicine. This study adds to the continuous endeavors in identifying safer and more efficient intracanal therapies, which are essential for improving patient outcomes in endodontic operations. How to cite this article: Alrashidi MA, Badawi MF, Elbeltagy MG, et al. The Effect of Glycyrrhizin on the Viability and Proliferation of Dental Pulp Stem Cells Compared to Intracanal Medicaments. J Contemp Dent Pract 2024;25(3):267-275.

An In Vitro Evaluation of the Antimicrobial Activity of Probiotics Against Endodontic Pathogens

Background and aim: Despite scientific evidence that even some microorganisms may be useful, endodontic intervention has persisted to prioritize the removal of all microorganisms from the root canal system. Indeed, information regarding the significant role of probiotic microorganisms in endodontic treatment has been sparse. This study aimed to carry out an in vitro evaluation of the antimicrobial activity of probiotics against endodontic pathogens.

Methods: The evaluation was carried out in three stages. In Stage 1, the agar cup well procedure was used to analyse the efficiency of probiotics microorganisms against Enterococcus faecalis bacteria and Candida albicans microorganisms in the planktonic stage. In Stage 2, a deferred antagonistic experiment was used to determine the activity of probiotic microorganisms against endodontic pathogens like E. faecalis and C. albicans in the planktonic phase. In Stage 3, biofilm phase evaluation of an intracanal probiotic microorganism carrier was done. The region of maximum inhibition was measured at the end of Stages 1 and 2. The antimicrobial activity was recognized when the dimension of the region of maximum inhibition was 10 mm or above. The colony-forming unit/millilitre was measured at the end of Stage 3.

Results: There was marked antimicrobial activity of probiotic microorganisms against the pathogenic microorganisms E. faecalis as well as C. albicans in Stages 1 and 3, i.e., during the evaluation involving agar cup and evaluation at the biofilm stage. However, no antimicrobial activity of probiotic microorganisms was observed against pathogenic endodontic microorganisms in Stage 2, i.e., during evaluation involving the use of the deferred antagonistic technique.

Conclusion: It can be concluded that probiotic therapy is a promising antibacterial treatment approach that should be further investigated. This study shows that probiotics can help effectively in endodontic treatment and that more in vitro as well as in vivo research is needed to fully appreciate the advantages of bacteriotherapy in the field of endodontics.

Antibacterial efficacy of antibiotic pastes versus calcium hydroxide intracanal dressing: A systematic review and meta-analysis of ex vivo studies

Background

Conflicting findings on the potency of antibiotic pastes versus calcium hydroxide (CH) have been evident in the literature.

Aims

To compare the antibacterial efficacy of single antibiotic paste (SAP), double antibiotic paste (DAP), triple antibiotic paste (TAP), and modified TAP (mTAP) with CH on bacterial biofilms.

Methods

PubMed, Scopus, and Embase were comprehensively searched until August 23, 2021. The study protocol was registered in the PROSPERO. Ex vivo studies performed on Enterococcus faecalis or polymicrobial biofilms incubated on human/bovine dentin were selected. The quality of the studies was assessed using a customized quality assessment tool. Standardized mean difference (SMD) with a 95% confidence interval (CI) was calculated for the meta-analysis. Meta-regression models were used to identify the sources of heterogeneity and to compare the efficacy of pastes.

Results

The qualitative and quantitative synthesis included 40 and 23 papers, respectively, out of 1421 search results. TAP (SMD = -3.82; CI, -5.44 to -2.21; P < 0.001) and SAPs (SMD = -2.38; CI, -2.81 to - 1.94; P < 0.001) had significantly higher antibacterial efficacy compared to the CH on E. faecalis biofilm. However, no significant difference was found between the efficacy of DAP (SMD = -2.74; CI, -5.56-0.07; P = 0.06) or mTAP (SMD = -0.28; CI, -0.82-0.26; P = 0.31) and CH. Meta-regression model on E. faecalis showed that SAPs have similar efficacy compared to TAP and significantly better efficacy than DAP. On dual-species (SMD = 0.15; CI, -1.00-1.29; P = 0.80) or multi-species (SMD = 0.23; CI, -0.08-0.55; P = 0.15) biofilms, DAP and CH had similar efficacy.

Conclusions

Ex vivo evidence showed that antibiotic pastes were either superior or equal to CH. The studied SAPs had considerably higher or similar antibacterial effectiveness compared to DAP, CH, and TAP. Hence, combined antibiotic therapy was not necessarily required for root canal disinfection ex vivo.

Trans-cinnamaldehyde potently kills Enterococcus faecalis biofilm cells and prevents biofilm recovery

Enterococcus faecalis is a biofilm-forming, nosocomial pathogen that is frequently isolated from failed root canal treatments. Contemporary root canal disinfectants are ineffective in eliminating these biofilms and preventing reinfection. As a result, there is a pressing need to identify novel and safe antibiofilm molecules. The effect of short-term (5 and 15 min) and long-term (24 h) treatments of trans-cinnamaldehyde (TC) on the viability of E. faecalis biofilms was compared with currently used root canal disinfectants. Treatment for 15 min with TC reduced biofilm metabolic activity as effective as 1% sodium hypochlorite and 2% chlorhexidine. Treatment with TC for 24 h was significantly more effective than 2% chlorhexidine in reducing the viable cell counts of biofilms. This serendipitous effect of TC was sustained for 10 days under growth-favoring conditions. For the first time, our study highlights the strong antibacterial activity of TC against E. faecalis biofilms, and notably, its ability to prevent biofilm recovery after treatment.

Antimicrobial activity of probiotics against endodontic pathogens:- A preliminary study

Introduction

The purpose of this study was to evaluate the antibacterial effectiveness of probiotics lactobacilli group and Bifidobacterium against Enterococcus faecalis and Candida albicans in both planktonic stage and biofilm stage.

Materials and Methods

Phase 1 of the study was conducted by agar well diffusion method. About 0.5 ml of test pathogen culture was inoculated on 20 ml of molten agar and allowed to solidify. 4-5 circular wells of diameter 8-10 mm were punched in each poured plates and 150 μl of diluted test samples were added to the wells. Phase 2 was deferred antagonism test, wherein purified culture of pathogen strain was streaked at right angle to the original producer growth and incubated at 37°C for 24 h. Zone of inhibition was measured for both the phases. Phase 3 biofilm stage evaluation was conducted by mixing 9 ml of 30% poloxamer 407 and De Man, Rogosa and Sharpe (MRS) broth in a test tube with 500 μl of either pathogen, together with 500 μl of test probiotic strains and incubated (37°C, 48 h), followed by serially diluting the mixture by 1 ml into 9 ml sterile saline till 10⁸ dilutions for evaluation of colony-forming unit/ml counts. Controls were endodontic pathogens in 30% poloxamer with MRS broth and no probiotics.

Results

Results were evaluated and statistically analysed using one-way analysis of variance and unpaired t-test. In the planktonic stage, probiotics showed inhibitory activity against endodontic pathogens with valid statistical significance (P < 0.05), while there was no activity by deferred antagonism method. In biofilm stage, all three probiotics showed growth reduction for E. faecalis, while lactobacilli group showed reduction in C. albicans colonies.

Conclusion

This preliminary study suggested that probiotics are effective for preventing the growth of endodontic pathogens in vitro. Poloxamer could be utilised as an ideal delivery vehicle for probiotics.

Antibacterial efficacy of several intracanal medicaments for endodontic therapy

The antibacterial efficacy of intracanal medicaments for 2 and 7 days, in open apex root canals contaminated with Enterococcus faecalis biofilms was compared. One hundred and thirty-eight standardized uniradicular human roots were inoculated with E. faecalis. Colony forming units (CFU) were recorded before and after medication. Samples were divided in two (2/7 days), and subdivided (n=8/group): triple antibiotic paste (TAP); double antibiotic paste (DAP); dental base paste (DBP), consisting of calcium hydroxide, propylene glycol and calcium carbonate; DBP+0.2% chlorhexidine (CHX); DBP+0.2% cetrimide (CTR); DBP+0.2% CHX+0.2% CTR; 2.5% sodium hypochlorite (NaOCl); and distilled water. At both periods TAP, DAP, DBP+0.2% CHX, DBP+0.2% CTR and DBP+0.2% CHX+0.2% CTR exhibited no growth (NG) of E. faecalis. Distilled water and 2.5% NaOCl obtained the lowest CFU reduction. No growth with DBP was reached only at 7 days. CHX and/or CTR pastes were as effective as DAP and TAP. A 2-day period provided an effective disinfection.

Evaluation of the Role of Probiotics in Endodontic Treatment: A Preliminary Study

Aims and Objectives:

The principal goal of endodontics is the prevention of periapical infection. Acute and chronic apical periodontitis occur due to the persistence of pathogenic microorganisms such as Enterococcus faecalis and Candida albicans harboring the root canal systems of the teeth. The concept of the use of probiotics in addressing endodontic disease is new and has not been studied adequately. On the basis of the success of probiotics in periodontal treatment, this preliminary work was performed (a) to evaluate the antibacterial efficacy of probiotics against common endodontic pathogens, i.e. E. faecalis and C. albicans, and (b) to evaluate the potential use of probiotic therapy as an additive in endodontic treatment procedures.

Materials and Methods:

Two commercial probiotics were selected and evaluated based upon the numbers and concentration of organisms. Pathogenic test organisms were C. albicans (ATCC 10231) and E. faecalis (ATCC 29212). Phase 1 of the study was conducted by agar cup method test to evaluate the antibacterial activity of the selected probiotics against E. faecalis and C. albicans by measuring zones of inhibition (ZOI) in mm. Microorganisms from probiotic samples were isolated following manufacturer's instructions. Pathogenic organisms were set to a 0.1 McFarland standard challenge. Circular wells of 8 mm diameter were punched in each of the poured plates. Appropriately diluted test samples were added to the above-punched wells. The volume of the solution added to each well was 100 μl. The plates were incubated in an upright position at 37°C for 24 hours under aerobic conditions. Post incubation, ZOI was measured (mm). Phase 2 was conducted by mixing 9 ml of 30% poloxamer 407 and de Man, Rogosa and Sharpe (MRS) broth in a test tube with 500 μl of either E. faecalis or C. albicans set at an optical density (OD) of 0.252, together with 500 μl of test probiotic strain, set at a respective OD. Samples were then incubated at 37°C for 48 hours, followed by serial dilutions by 1 ml till 10⁸. This was done to calculate colony forming units (CFU)/ml counts. Controls used were endodontic pathogens in 30% poloxamer with MRS broth without any probiotic group.

Results:

Probiotic groups showed inhibitory activity against E. faecalis by the agar cup method, whereas there was no effect on C. albicans. In the biofilm stage, both the test groups had an antibacterial effect on pathogenic organisms.

Conclusion:

This study suggests that probiotic organisms of the species Lactobacillus and Bifidobacterium are effective for preventing the growth of E. faecalis and C. albicansin vitro. Because probiotics are available in varied compositions and concentrations, further evaluation for their role in treating endodontic infection is suggested and warranted. In addition, the study suggested that poloxamer 407 could be utilized as an ideal delivery vehicle for probiotics for use as a potential endodontic intracanal medicament.