Evaluation of Antimicrobial Effects of Different Concentrations of Triple Antibiotic Paste on Mature Biofilm of Enterococcus faecalis

Bactericidal Effect of Triple Antibiotic Paste against Enterococcus faecalis in Dentinal Tubules: An Ex Vivo Study

OBJECTIVE

The aim of this study was to investigate the bactericidal effect of various concentrations of triple antibiotic paste (TAP) against Enterococcus faecalis (E. faecalis) in dentinal tubules using a bacterial culture assay and confocal laser scanning microscope (CLSM).

METHODS

Ninety human teeth were contaminated with E. faecalis (ATCC 29212) and randomly allocated into 5 groups; the negative control (without TAP), 1 mg/ml, 5 mg/ml, 7.5 mg/ml and 10 mg/ml TAP (n=18). After a 3-week TAP treatment, samples were collected from the root canal space, root dentin at 100-μm and 200-μm depth. The collected samples were subjected to a bacterial culture assay (n=10). Eight roots from each group underwent CLSM analysis to determine the live/dead bacterial cells.

RESULTS

The bacterial culture assay results indicated that the negative control samples were all culturable. The number of culture-positive samples decreased after TAP treatment at 1, 5, 7.5 and 10 mg/ml, with 2, 2, 1 and 0 culturable samples, respectively. However, there was no significant difference among the TAP treatments. Surprisingly, the CLSM analysis demonstrated live bacteria in the dentinal tubules in all samples. The negative control had 52.36%+-3.24 live bacteria. TAP treatment at 10 mg/ml had the lowest percentage of live bacterial cells (40.58%+-5.40), followed by 7.5 mg/ml (44.14%+-6.03), 5 mg/ml (46.31%+-5.32) and 1 mg/ml (52.55%+-8.82). The percentage of live cells in the 10 mg/ml, 7.5 mg/ml and 5 mg/ml TAP groups were significantly lower than the 1 mg/ml TAP and negative control groups.

CONCLUSION

TAP treatment significantly decreased the percentage of viable E. faecalis cells in the dentinal tubules and its bactericidal effect was dose-dependent.

In vitro bactericidal efficacy of a new triple antibiotic paste formulation against Enterococcus faecalis biofilm

The aim of this study was to evaluate the bactericidal efficacy on Enterococcus faecalis biofilm of a novel, low-concentration triple-antibiotic paste (TAP-L2) in propylene glycol/carboxymethylcellulose vehicle (VEH-2), a ready-to-use prototype, compared with two currently used products; a low-concentration (TAP-L1) and a high-concentration paste (TAP-H1) mixed in macrogol/propylene glycol vehicle (VEH-1). Sixty-two root canals were infected with E. faecalis biofilm, medicated with (a) TAP-L1, (b) TAP-L2, (c) TAP-H1, (d) VEH-1 or (e) VEH-2 (n = 10) and incubated for 21 days. Live/dead assays were performed using confocal laser scanning microscopy (CLSM), and dead bacteria (%) were calculated. The TAP-H1 group demonstrated the highest dead bacteria (67.54 ± 2.38%), which was significantly higher than the TAP-L2 and TAP-L1 groups (56.85 ± 7.11% and 54.23 ± 10.19%) (p < 0.05). The TAP groups demonstrated significantly higher dead bacteria than the VEH-1 and VEH-2 groups (47.51 ± 6.41% and 45.14 ± 8.28%) (p < 0.05). The ready-to-use TAP-L2 had antibacterial activity comparable to TAP-L1, both of which were lower than TAP-H1.

Efficacy of disinfection procedures performed prior to regenerative endodontic therapy: An integrative review

The aim of this integrative review was to identify whether the disinfection procedures performed prior to regenerative endodontic treatment were effective on biofilm removal from the root canals. The research was based on PubMed, Latin American and Caribbean Health Sciences Literature (Lilacs) and Scientific Electronic Library Online (SciELO) databases. Four articles were selected; one of the studies was in vivo and the others ex vivo. Different disinfection procedures were studied, characterised mainly by the use of intracanal medication, highlighting the double antibiotic paste, triple antibiotic paste and calcium hydroxide paste. Disinfection ability was evaluated against Enterococcus faecalis and multispecies biofilms by using the fluorescence technique and colony forming unit counting, for 7 to 21 days. Double antibiotic paste and triple antibiotic paste demonstrated excellent antibiofilm activity, unlike CH paste that showed limited disinfection, even when associated with different antimicrobial agents. Triple antibiotic paste was the most effective medication against biofilm.

Immediate and Delayed Post Space Preparations in Endodontically Treated Teeth: A Scoping Review

BACKGROUND

The aim of the present review was to identify the effect of the post-space preparation (PSP) timing (immediate or delayed) on endodontically treated teeth.

METHODS

All studies in any language that compared the effect of immediate versus delayed PSP on the outcomes of an endodontically treated tooth were searched in PubMed, Scopus, Web of Science, Cochrane, ProQuest, WorldCat, and Google Scholar databases by two independent researchers until February 12, 2022. Studies assessing merely the immediate or delayed PSP were excluded. A descriptive analysis was performed to evaluate the study design and the characteristics of the included studies.

RESULTS

The initial search yielded 2612 records, of which 68 were included. Except for one randomized controlled trial, all were in vitro. The evaluated variables were apical/coronal microleakage (n = 48/n = 1), post-bond strength (n = 8), bacterial infiltration (n = 7), presence of voids (n = 3), apical extrusion and residual of filling material (n = 1), and post-operative pain (n = 1). The number of publications had steady growth per year and fast growth per decade. "Post-space preparation" was the most popular keywords.

CONCLUSIONS

The present review highlights the need for further investigations due to the various design of studies, controversial results, and an inadequate number of randomized controlled trials.

TRIAL REGISTRATION

Retrospectively registered. Open Science ( https://doi.org/10.17605/OSF.IO/2YTM6 ).

Effect of three intracanal medicaments used in pulp regeneration on the push-out bond strength of mineral trioxide aggregate and calcium-enriched mixture: An in vitro study

Background. The bond strength of the materials used as a cervical barrier in the pulp regeneration is essential for the success of treatment. This study aimed to evaluate the effects of triple antibiotic paste (TAP), double antibiotic paste (DAP), and simvastatin as intracanal medicaments on the dislodgement resistance of mineral trioxide aggregate (MTA) and calcium-enriched mixture (CEM). Methods. A total of 160 extracted human single-rooted teeth were selected, and root canal preparation was carried out. The teeth in each group were randomly divided into four subgroups: TAP, DAP, simvastatin, and the control group (without intracanal medicament). Four weeks after placing the medicaments, it was removed by sodium hypochlorite, and MTA and CEM were placed in the coronal third of the root canals. After a week, 2-mm-thick dentin disks were prepared from the coronal third of the roots, and the push-out test was performed using a universal testing machine. The data were analyzed using two-way ANOVA and independent t-test at a significance level of 0.05. Results. Regardless of the intracanal medicament, there was no significant difference between the overall bond strength of MTA (59.3±10 MPa) and CEM (55.8±11 MPa) (P=0.6). Furthermore, there were no significant differences in bond strength between the two intracanal medicament groups and the control group (P>0.05). Conclusion. Under the limitations of the current study, DAP, simvastatin, and TAP, as intracanal medicaments, did not adversely affect the push-out bond strength of CEM and MTA.

Antimicrobial effects of different concentrations of simvastatin versus triple antibiotic paste on Enterococcus faecalis biofilms at different stages of development

Background. This study assessed the antimicrobial effects of different concentrations of simvastatin versus triple antibiotic paste (TAP) on Enterococcus faecalis biofilms at different stages of development. Methods. In this in vitro study, 70 human single-rooted mature premolars were decoronated, instrumented, and autoclave-sterilized. Next, an E. faecalis suspension was prepared and inoculated into the canals to obtain 4- and 6-week biofilms. After ensuring biofilm formation, the samples in each group were randomly assigned to 5 subgroups (n=12): 1 mg/mL TAP, 10 mg/ mL TAP, 1 mg/mL simvastatin, 10 mg/mL simvastatin, and positive control (phosphate-buffered saline solution). The medicaments were applied in the canals, and the teeth were incubated for one week. Dentin samples were collected by a rotary file, cultured, and the number of E. faecalis colonies was counted. The Kruskal-Wallis, Mann-Whitney U, and Wilcoxon tests were used for data analysis (α=0.05). Results. There were significant differences in colony counts between the two concentrations of TAP and the control group against both 4- and 6-week biofilms (P<0.05). The antibacterial effect of 10 mg/mL TAP and simvastatin was stronger than that of 1 mg/mL concentration against the 4- and 6-week E. faecalis biofilms (P<0.05). Furthermore, 10 mg/mL TAP and simvastatin were more effective against the 4-week biofilms than the 6-week biofilms (P<0.05). Conclusion. According to the present results and since biofilms may remain viable in the root canal system for weeks to months, applying 10 mg/mL TAP and simvastatin might be more effective.

Evaluation of tissue inflammatory response of four intracanal medicament - An animal study

Aim:

The aim of the study was to evaluate the tissue inflammatory response of origanum vulgarae, omeprazole, triple antibiotic paste (TAP), and calcium hydroxide in an animal model.

Materials and Methods:

Seventy Five male Wistar rats were randomly divided into four experimental groups and one control group: Group 1: control (n = 15), Group 2: 0.25 mg origanum vulgarae/1 ml of cellulose (n = 15), Group 3: 2 mg omeprazole/1 ml of distilled water (n = 15), and Group 4: 1 mg TAP/1 ml of distilled water (n = 15), Group 5: 16 mg calcium hydroxide/1 ml of distilled water (n = 15). A trough was made in the periapical bone and the medicament of the respective groups was placed. After the 7^th, 14^th, 28^th and days, the animals were euthanized and tissue specimen was prepared for histological examination.

Results:

The results were analyzed statistically. On the 7^th and 14^th days, all the experimental groups showed severe inflammatory response with no statistical significance, whereas on the 28^th day, the inflammatory response was graded based on the mean value, in which omeprazole showed moderate inflammatory cells followed by TAP. Mild inflammatory response was seen in calcium hydroxide and origanum vulgarae, showing no statistical significance.

Conclusion:

Within the limitation of the study, severe inflammatory response was reported on the 7^th and 14^th days in all experimental groups, whereas on 28^th day, there was a moderate inflammatory response seen in omeprazole, followed by TAP. Calcium hydroxide and origanum vulgarae showed a mild inflammatory response.

Antimicrobial Efficacy of Intracanal Medicaments against E. Faecalis Bacteria in Infected Primary Molars by Using Real-Time PCR: A Randomized Clinical Trial

Aim

This study aimed to compare the antimicrobial efficacy of calcium hydroxide (CH) and triple antibiotic paste (TAP) against E. faecalis bacteria in infected primary molars.

Methods and Materials

Thirty-nine 4–6-year-old children with an infected primary molar were randomly divided into three equal groups (n = 13) to receive either CH or TAP and an untreated control group. Following access cavity preparation, the first microbiological samples (S1) were collected by using absorbent paper points. The canals were prepared and rinsed. Then, CH or TAP was applied in the root canals. Seven days later, the second microbiological samples (S2) were collected. DNA extraction was performed to count E. faecalis bacteria by using real-time PCR for S1 and S2 samples. Data were analyzed through one-way ANOVA and Tukey's test (α = 0.05).

Results

E. faecalis bacteria counts decreased significantly in CH and TAP groups compared with the control group (P ≤ 0.001). However, no statistically significant difference existed between these two groups (P=0.698).

Conclusion

Both TAP and CH have significant antimicrobial effects as intracanal medicament between the treatment sessions in infected primary teeth.

Responses of oral-microflora-exposed dental pulp to capping with a triple antibiotic paste or calcium hydroxide cement in mouse molars

Introduction

Responses of oral-microflora-exposed dental pulp to a triple antibiotic paste (TAP), a mixture of ciprofloxacin, metronidazole, and minocycline in ointment with macrogol and propylene glycol, remain to be fully clarified at the cellular level. This study aimed to elucidate responses of oral-microflora-exposed dental pulp to capping with TAP in mouse molars.

Methods

A cavity was prepared on the first molars of 6-week-old mice to expose the dental pulp for 24 h. The exposed pulp was capped with TAP (TAP group) or calcium hydroxide cement (CH group), in addition to the combination of macrogol (M) and propylene glycol (P) (MP, control group), followed by a glass ionomer cement filling. The samples were collected at intervals of 1, 2, and 3 weeks, and immunohistochemistry for nestin and Ki-67 and deoxyuride-5′-triphosphate biotin nick end labeling (TUNEL) assay were performed in addition to quantitative real-time polymerase chain reaction (qRT-PCR) analyses.

Results

The highest occurrence rate of pulp necrosis was found in the control group followed by the CH group at Weeks 2 and 3, whereas the highest occurrence rate of healed areas in the dental pulp was observed in the TAP group at each time point. Tertiary dentin formation was first observed in the dental pulp of the TAP group at Week 2. In contrast, bone-like and/or fibrous tissues were frequently observed in the CH group. qRT-PCR analyses clarified that TAP activated the stem and dendritic cells at Weeks 1 and 2, respectively.

Conclusions

The use of TAP as a pulp-capping agent improved the healing process of oral-microflora-exposed dental pulp in mouse molars.

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We established a mouse model to evaluate the pulpal responses to capping materials.

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TAP induced odontoblast-like cell differentiation faster than calcium hydroxide.

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Tertiary dentin was predominantly seen at the exposure site in the TAP group.

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TAC-P tends to activate dental pulp stem cells earlier than calcium hydroxide.

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TAP favored the repair process of the oral-microflora-exposed pulpal tissue.

Combined Effect of a Mixture of Silver Nanoparticles and Calcium Hydroxide against Enterococcus faecalis Biofilm

INTRODUCTION

The aim of this study was to evaluate the antibiofilm effectiveness of calcium hydroxide (Ca[OH]₂) mixed with 0.02% silver nanoparticles (AgNPs) in comparison with 1 mg/mL triple antibiotic paste (TAP), Ca(OH)₂, and 0.02% AgNPs against Enterococcus faecalis using confocal laser scanning microscopy.

METHODS

Ninety dentin disks were prepared, sterilized, and inoculated with E. faecalis to establish a 3-week-old biofilm model. The samples received 1 mg/mL TAP, a mixture of Ca(OH)₂ + 0.02% AgNPs, Ca(OH)₂, or 0.02% AgNPs (n = 20/group). Specimens in each group were equally subdivided into 2 groups and incubated for 2 and 4 weeks. Untreated dentin disks (n = 10) were exposed to sterile saline solution and acted as a positive control. Sterile dentin disks (n = 10) were incubated anaerobically in brain-heart infusion broth and served as a negative control. At the end of each observation period, the specimens were stained with LIVE/DEAD BacLight dye (Molecular Probes, Eugene, OR) and analyzed with confocal laser scanning microscopy to determine the proportion of dead cells in the biofilm. Statistical analysis was performed using the generalized linear model repeated measure and Tukey tests (P < .05).

RESULTS

A significantly greater proportion of dead cells was observed in the samples treated with 1 mg/mL TAP (90.39% and 99.41%) and a mixture of Ca(OH)₂ + AgNPs (90.85% and 98.49%) than those in the samples treated with Ca(OH)₂ (76.14% and 91.71%) and AgNPs (62.83% and 88.07%) at 2 and 4 weeks, respectively. A significant difference in the antibiofilm effectiveness was observed among the groups (P < .05), except for 1 mg/mL TAP and the mixture of Ca(OH)₂ + AgNPs (P > .05). All medicaments showed a significant difference in antibiofilm efficacy at the 2 time points.

CONCLUSIONS

The mixture of Ca(OH)₂ + AgNPs showed a high antibiofilm effect and was not significantly different from 1 mg/mL TAP. Furthermore, long-term contact between intracanal medicaments and bacterial cells achieved significant antibiofilm efficacy.

The Effects of Intracanal Irrigants and Medicaments on Dental-Derived Stem Cells Fate in Regenerative Endodontics: An update

Regenerative endodontics is a biologically based treatment designed for immature permanent teeth with necrotic pulp to replace dentin and root structures, as well as dental pulp cells. This procedure has become a part of novel modality in endodontics therapeutic manner, and it is considered as an alternative to apexification. In the last decade, numerous case reports, which describe this procedure, have been published. This therapeutic approach succeeded due to its lower financial cost and ease of performance. Although the clinical protocol of this procedure is not standardized and the effects of irrigants and medicaments on dental stem cells fate remain somewhat ambiguous, however when successful, it is an improvement of endodontics treatment protocols which leads to continued root development, increased dentinal wall thickness, and apical closure of immature teeth. To ensure a successful regenerative procedure, it is essential to investigate the appropriate disinfection protocols and the use of biocompatible molecules in order to control the release of growth factors and the differentiation of stem cells. This is the first review in the literature to summarize the present knowledge regarding the effect of intracanal irrigants and medicaments on the dental derived stem cells fate in regenerative endodontic procedures.

Comparison of Antibacterial Effects of Photodynamic Therapy, Modified Triple Antibiotic Paste and Calcium Hydroxide on Root Canals Infected With Enterococcus faecalis: An In Vitro Study

Introduction: A pivotal issue to achieve success in the treatment of the root canal is root canal disinfection. One of the most important bacteria that infect the root canal is Enterococcus faecalis. This study seeks to examine the effectiveness of 3 methods for disinfecting the root canal: photodynamic therapy, modified triple antibiotic paste (MTAP), and calcium hydroxide. Methods: Sixty-two single-rooted extracted anterior teeth were collected. After cleaning and disinfecting the teeth, their crowns were cut at the CEJ point. The root canals were shaped to the working length up to file F3 ProTaper (F1, F2, F3). EDTA 17% and sodium hypochlorite 2.5% were used for 5 minutes to wash and remove the smear layer, and then the apical foramen was sealed using composite. After that, the teeth were sterilized in an autoclave at 121°C for 15 minutes. Then 10 samples were taken randomly as the negative control. The remaining samples were immersed and cultivated in a suspension containing E. faecalis for 21 days. Then the samples were divided into 5 groups: 2 positive control groups, 1 group treated with the antibiotic paste with the concentration of 1 mg/mL, 1 group treated with calcium hydroxide, and 1 group treated with photodynamic therapy. Then, to collect the biofilm, the ProTaper file F4 was used. After that, the microbial suspension was provided and counting the colonies was carried out to compare the groups. Results: The findings indicated that the amount of CFU/mg of MTAP samples, including clindamycin, metronidazole, ciprofloxacin in the concentration of 1 mg/mL and photodynamic therapy and calcium hydroxide was lower than that in the control group. Antibiotic paste cleansed the root canal up to 99.9%. Photodynamic therapy reduced the amount of CFU/mg to 98.8%, and calcium hydroxide reduced the amount of CFU/mg to 94.13%. Conclusion: Using photodynamic therapy causes a reduction in the biofilm and inhibits the growth of the E. faecalis bacterium. In addition, in this study, MTAP with a concentration of 1 mg/mL was used, which expunged the bacteria completely. Meanwhile, calcium hydroxide had the weakest effect of all on the E. faecalis bacterium.

Effect of Intracanal Medicaments on Pull-Out Bond Strength of Fiber Post Cemented with a Self-Adhesive System

OBJECTIVES

 This study aimed to assess the effect of four intracanal medicaments on pull-out bond strength of fiber posts.

MATERIALS AND METHODS

 A total of 65 single-rooted, single-canal teeth were selected and decoronated. Root canals were prepared and after rinsing were randomly divided into five groups (n = 13). G₁: calcium hydroxide (CH), G_2: CH plus chlorhexidine (CH+CHX), G₃: triple antibiotic paste (TAP), G₄: double antibiotic paste (DAP) were applied in the canals in the four groups. The control group (G₅) received no medicament. After 4 weeks, the medicaments were rinsed off and the canals were filled with gutta-percha. Post space was then prepared in root canals for the placement of glass fiber posts and self-adhesive cement (Panavia F2). After cementation, they were subjected to pull-out bond strength test.

STATISTICAL ANALYSIS

 Data were statistically analyzed using one-way analysis of variance and Tukey test.Results The pull-out bond strength values were significantly different in the groups (p < 0.001). The highest values of bond strength were seen in G₂, G₁, and G₃ (359.97 ± 81.26, 333.79 ± 98.96, 309.27 ± 78.07), respectively. There was no significant difference between G₄ and G₅ (p = 0.75).

CONCLUSION

 The results showed that CH, CH+CHX, and TAP enhanced the pull-out bond strength of fiber post to root canal wall as compared to the control group.

Effects of different intra canal medicaments on the push out bond strength of endodontic sealers

BACKGROUND

One of the essential properties of the root canal sealers is the adhesion to root canal dentin and their higher bond strength decreases the microleakage. The aim of the present study was to compare the effect of Different Intracanal medicaments on the push out bond strength of AH26 and MTA Fillapex sealers.

MATERIAL AND METHODS

A total of 104 one-rooted extracted human teeth were divided into 4 (n=26) experimental groups. After the cleaning and shaping, the root canals were filled with Ca(OH)2, triantibiotic paste (TAP), Metapex or 2% chlorhexidine gel for two weeks. Then, intracanal medicaments were rinsed away and the samples in the sub-groups were obturated with gutta-percha and AH26 or MTA Fillapex sealers. After two weeks incubation, 2-mm-thick middle section of each root was then subjected to push-out testing. Data were analyzed with two-way ANOVA and LSD test.

RESULTS

With all the intracanal medicaments, the overall mean of bond strength values were significantly higher with AH26 compared to MTA Fillapex (p<0.05). With the use of MTA Fillapex the maximum and minimum means of bond strength values were recorded with CHX and Metapex and for AH26 were recorded with Ca(OH)2 and chlorhexidine, respectively.

CONCLUSIONS

The bond strengths of sealers to dentin are under the influence of pre-treatment with intracanal medicaments. Under the limitations of the present study, the effect of TAP on the bond strength of endodontic sealers was not negative. Key words:AH26, medicament, MTA Fillapex, push-out bond.

Antimicrobial efficacy of different concentration of sodium hypochlorite on the biofilm of Enterococcus faecalis at different stages of development

Background

Persistent infection of the root canal due to the presence of resistance bacterial species, such as Enterococcus faecalis, has always been one of the most important reasons for endodontic treatment failure. This study investigated the antimicrobial efficacy of 1%, 2.5 % and 5% sodium hypochlorite in eliminating E. faecalis biofilms at different stages of development.

Material and Methods

In this study 4-, 6- and 10-week-old E. faecalis biofilms were subjected to one of the following approaches: phosphate-buffered saline solution (PBS) or 1%, 2.5% and 5% NaOCl. Dentin chip suspensions were used for colony forming unit (CFU) counting to estimate remaining E. faecalis counts. Statistical comparison of the means was carried out with Kruskal-Wallis test, and pair-wise comparisons were made by Mann-Whitney U test, at a significance level of P<0.05.

Results

The results showed that 2.5% and 5% NaOCl completely eliminated E. faecalis biofilms in three stages of biofilm development, whereas 1% NaOCl resulted in 85.73%, 81.88% and 78.62% decreases in bacterial counts in 4-, 6- and 10-week-old biofilms, respectively, which was significantly more than those with PBS (p<0.05).

Conclusions

The bacteria in mature and old biofilms were more resistant to 1% NaOCl than were the bacteria in young biofilms. Overall survival rate and residual bacteria increased with biofilm aging.

Key words:Antibacterial, biofilm, E. faecalis, sodium hypochlorite.