Residual antibiofilm effects of various concentrations of double antibiotic paste used during regenerative endodontics after different application times

Visual Antimicrobial Gold Nanocluster Hydrogel with Inflammation-Responsive and Time-Regulated Swelling/Degradation for Regenerative Endodontic Procedures

Regenerative endodontic procedures (REPs) have become the primary therapy for immature permanent teeth. Double antibiotic (DA, ciprofloxacin, and metronidazole) is recommended as the intracanal medicament in REPs. However, it has several limitations, such as toxicity to stem cells, short-term antibacterial efficacy, and inability to be visualized radiographically. In this study, a method is induced to construct an antimicrobial gold nanocluster (Au NC) hydrogel loading DA (DA@Au NCs) via electrostatic interactions and disulfide bond generation for REPs. As exposed to interstitial fluid from root canal infection, DA@Au NCs can swell and fill the canal to thoroughly contact with bacteria in its biofilm. The increasing interstitial fluid and its internal protease can trigger the degradation of DA@Au NC hydrogel to release DA, and it has been found that the cross-linking time of hydrogel can regulate its degradation time because of the positive correlation between them. Au NC hydrogel has the characteristics of radiographical visualization to track the drug location and release dynamics. These properties can improve the antimicrobial efficiency, achieve long-term antibacterial effects, and reduce cells toxicity. Moreover, the hydrogel can also kill planktonic bacteria and biofilm, even penetrating dentin tubules. Attributed to the introduction of Au NCs, it also supports stem cell proliferation, migration, adhesion, and mineralization by regulating the expression of alkaline phosphatase (ALP). The in vivo experiments also verified that the multiple properties of DA@Au NC hydrogel offer a solution to address the problem of REPs.

A prospective case series in regenerative endodontics: The effective use of diluted antibiotic hydrogels in endodontic regeneration procedures

Objective

to investigate the effectiveness of diluted antibiotic hydrogels in endodontic regeneration procedures.

Materials and Methods

One conventional treatment (calcium hydroxide) and two experimental treatments containing 1 mg/mL antibiotic in gel (MC-TAP and MC-DAP) were prepared for this study. The effect of these medicaments on the proliferation and differentiation potential of dental pulp stem cells (DPSCs) was examined before their clinical use, using WST and ALP assays. Twenty-two teeth diagnosed with necrotic immature roots were treated with calcium hydroxide, MC-TAP or MC-DAP using the endodontic regeneration protocol as described by the American Association of Endodontists (AAE). Teeth were examined after application of the medicament, at the time of regeneration and after 12-24 months.

Results

All treated teeth showed resolution of signs and symptoms shortly after treatment with the different medicaments. However, signs and symptoms returned a few months after initial treatment in clinical cases treated with MC-DAP. All successfully treated teeth examined after 12-24 months were free of signs and symptoms, but vitality was not achieved.

Conclusion

Low concentration antibiotic gel containing triple antibiotic paste (MC-TAP) can be successfully used for endodontic regeneration procedures.

Direct and residual antimicrobial effect of 2% chlorhexidine gel, double antibiotic paste and chitosan- chlorhexidine nanoparticles as intracanal medicaments against Enterococcus faecalis and Candida albicans in primary molars: an in-vitro study

BACKGROUND

Thorough disinfection of root canals in primary molars may be complicated by the complex root canal morphology. This in-vitro study aimed to compare direct and residual antimicrobial effect of 2% chlorhexidine (CHX) gel, 500 mg/ml double antibiotic paste (DAP) and chitosan-chlorhexidine nanoparticles (CS-CHX NPs) as intracanal medicaments against Enterococcus faecalis (E. faecalis) and Candida albicans (C. albicans) in primary molars.

METHODS

Mesial roots of 63 mandibular second primary molars were infected with E. faecalis and C. albicans. Teeth were divided into 9 groups: Ia: (CS-CHX NPs), IIa: (CHX), IIIa: (DAP), IVa: chitosan nanoparticles (CSNPs) in which medicaments were placed for 3 days, groups Ib: (CS-CHX NPs), IIb: CHX, IIIb: (DAP), IVb: (CSNPs) in which medicaments were placed for 7 days, and Group V (control): teeth were infected, irrigated with saline, and sampled 3- and 7-days post-infection. Microbiological samples were obtained after infection, 3, and 7 days after medicament placement and 7 days after medicament removal for both time points. One-way ANOVA, Tukey's post hoc test and paired t-test were used at p < 0.05.

RESULTS

CS-CHX NPs had the highest anticandidal effect which was comparable to CHX and significantly higher than other medicaments (p < 0.001) at both time points. CS-CHX NPs had the highest effect against E. faecalis which was comparable to DAP and significantly higher than other medicaments (p < 0.001) at 3 days. All medicaments showed similar effect against E. faecalis after 7 days. The 7-days placement significantly increased the antimicrobial effect against both micro-organisms in all groups, except CS-CHX NPs which showed an insignificant increase. CS-CHX NPs showed the highest residual effect against both micro-organisms that increased with 7-days placement.

CONCLUSION

CSNPs and CHX combination showed a synergistic effect against both micro-organisms. CS-CHX NPs displayed a higher effect at a shorter period compared to other medicaments, yet its residual effect was higher with 7-days placement.

Comparison of Antimicrobial Activity of Triple, Double, and Cefixime-Based Antibiotic Pastes Against Enterococcus Faecalis: An In Vitro Study

AIM

This in vitro study aims to compare the antimicrobial efficacy of triple antibiotic paste, double antibiotic paste, and cefixime-based triple antibiotic paste against Enterococcus faecalis. Materials and methods: Fifty single-rooted, caries-free, permanent teeth without any developmental defects were included in this study. The specimens were divided into five groups, with each group consisting of 10 teeth that received a specific medicament. The groups were as follows: Group I: control; Group II: calcium hydroxide; Group III: triple antibiotic paste; Group IV: double antibiotic paste; and Group V: cefixime-based triple antibiotic paste. The antimicrobial activity of the medicaments was assessed against E. faecalis at the end of the seventh and 14th days. The colony-forming units (CFU) were calculated using the Kolmogorov-Smirnov and Wilcoxon tests.

RESULTS

After seven days of the experimental process, it was observed that the CFU count was highest in group I and lowest in group V. In a similar vein, after 14 days, the maximum decrease in CFU count was observed in Group V, while the least reduction in CFU count was observed in Group II. On intergroup comparison, it was found that the maximum decrease in CFU was noted in Group V, followed by Group IV, Group III, and Group II.

CONCLUSION

The study results indicated that the cefixime-enriched antibiotic paste had the greatest antimicrobial effectiveness, while the double and triple antibiotic pastes offered superior antibacterial efficacy against E. faecalis at the end of the seventh and 14th days.

Effect of Dietary Supplements with ω-3 Fatty Acids, Ascorbic Acid, and Polyphenolic Antioxidant Flavonoid on Gene Expression, Organ Failure, and Mortality in Endotoxemia-Induced Septic Rats

Sepsis syndrome develops through enhanced secretion of pro-inflammatory cytokines and the generation of reactive oxygen species (ROS). Sepsis syndrome is characterized by vascular hyperpermeability, hypotension, multiple organ dysfunction syndrome (MODS), and increased mortality, among others. Endotoxemia-derived sepsis is an important cause of sepsis syndrome. During endotoxemia, circulating endotoxin interacts with endothelial cells (ECs), inducing detrimental effects on endothelium function. The endotoxin induces the conversion of ECs into fibroblasts, which are characterized by a massive change in the endothelial gene-expression pattern. This downregulates the endothelial markers and upregulates fibrotic proteins, mesenchymal transcription factors, and extracellular matrix proteins, producing endothelial fibrosis. Sepsis progression is modulated by the consumption of specific nutrients, including ω-3 fatty acids, ascorbic acid, and polyphenolic antioxidant flavonoids. However, the underlying mechanism is poorly described. The notion that gene expression is modulated during inflammatory conditions by nutrient consumption has been reported. However, it is not known whether nutrient consumption modulates the fibrotic endothelial gene-expression pattern during sepsis as a mechanism to decrease vascular hyperpermeability, hypotension, MODS, and mortality. Therefore, the aim of this study was to investigate the impact of the consumption of dietary ω-3 fatty acids, ascorbic acid, and polyphenolic antioxidant flavonoid supplements on the modulation of fibrotic endothelial gene-expression patterns during sepsis and to determine the effects on sepsis outcomes. Our results indicate that the consumption of supplements based on ω-3 fatty acids and polyphenolic antioxidant flavonoids was effective for improving endotoxemia outcomes through prophylactic ingestion and therapeutic usage. Thus, our findings indicated that specific nutrient consumption improves sepsis outcomes and should be considered in treatment.

The antimicrobial efficacy of graphene oxide, double antibiotic paste, and their combination against Enterococcus faecalis in the root canal treatment

BACKGROUND

Inter-appointment medication of the root canals with appropriate intracanal medicaments has been advocated to improve root canal disinfection. Graphene oxide (GO) has shown promising antimicrobial activity against a wide range of microorganisms, besides the capability of carrying antibiotics. The current study aimed to compare the antibacterial activity of double antibiotic paste (DAP) and GO per se and in combination (GO-DAP) against Enterococcus faecalis (E. faecalis).

METHODS

A total of 108 extracted human mandibular premolars were contaminated with three-week-old E. faecalis and subjected to a primary microbial assessment. The samples were categorized into 15 groups concerning the intracanal medicament (DAP, GO, GO-DAP, and control) and contact time (1, 7, and 14 days). Then, the root canals were medicated, incubated, and resubjected to a secondary antimicrobial evaluation. The colony-forming units (CFU) were counted to calculate the antimicrobial efficacy. The data were analyzed via the Kruskal-Wallis test (α = 0.05).

RESULTS

GO-DAP was the only medicament that completely eradicated E. faecalis in 1 day. The percentage reduction of CFU/ml in the GO-DAP and DAP groups was higher than that in the GO group at all allocated contact times. Furthermore, a significant decrease of the CFU/ml was seen in the GO and DAP groups after 7 and 14 days of being medicated (P < 0.05).

CONCLUSION

Since GO-DAP improved root canal disinfection, this novel material can be introduced as a promising intracanal medicament against E. faecalis even in the short run.

Evaluation of the efficacy of a novel antibiotic-steroid paste versus conventionally used intracanal antibiotic pastes and irrigating solutions against a 3-week-old biofilm of Enterococcus faecalis

Introduction

Intracanal medicaments have been used during endodontic regenerative procedures to eradicate endodontic pathogens.

Aims

The aim of our study was (1) to evaluate the antimicrobial efficacy of a novel antibiotic-steroid paste over the regularly used calcium hydroxide (Ca (OH)₂), double antibiotic paste (DAP), and modified triple antibiotic paste (M-TAP) and (2) to check the antimicrobial efficacy of irrigating solutions, Chlorhexidine (CHX), and sodium hypochlorite (NaOCl) against a 3-week-old Enterococcus faecalis (E. faecalis) biofilm.

Materials and Methods

A total of 112 human extracted teeth were contaminated with E. faecalis for a period of 21 days. A novel antibiotic-steroid paste, Ca (OH) ₂, DAP, M-TAP, and a placebo were placed inside the canal, sealed, and incubated in an aerobic environment at 37°C. For irrigating solutions, each prepared sample was immersed in 1 ml of sterile saline for 1 min, followed by irrigating and immersion with 1.5% NaOCl and 2% CHX for 5 min. An antimicrobial assessment was performed at the end of 2 days and 7 days, with seven teeth from each group, for each time interval. Dentin debris collected was transferred to the respective medium for culture. After 24 h, colonies were counted using classical bacterial counting technique as colony-forming units.

Results

Statistical analysis revealed that the novel antibiotic-steroid paste showed a statistically insignificant difference when compared to DAP, which had the highest antimicrobial properties.

Conclusion

This novel functional paste has antimicrobial efficacy comparable with that of DAP.

Effects of radiopaque double antibiotic pastes on the proliferation, alkaline phosphatase activity and mineral deposition of dental pulp stem cells

OBJECTIVE

The aim of this study was to investigate the effects of two radiopaque agents, barium sulfate (BaSO₄) or zirconium oxide (ZrO₂) in double antibiotic paste (DAP), on the proliferation and mineral deposition of human dental pulp stem cells (DPSC).

MATERIALS AND METHODS

Radiopaque antimicrobial medicaments composed of methylcellulose (MC) thickening polymer with BaSO₄ or ZrO₂ and either 1 or 5 mg/mL DAP (equal portions of metronidazole and ciprofloxacin) were used to investigate DPSC proliferation after 3 days, and alkaline phosphatase (ALP) activity and mineral deposition after 7 and 14 days. Radiopaque agents without DAP and Ca(OH)₂ were used as controls.

RESULTS

MC-BaSO₄ DAP and MC-ZrO₂ DAP at 1 or 5 mg/mL had no adverse effect on DPSC proliferation, compared to the media and MC controls. MC-ZrO₂ (DAP-free) greatly increased ALP activity after 7 days. DPSC mineral deposition was modestly reduced at 7 days by MC-BaSO₄ DAP and MC-ZrO₂ DAP, but not by DAP-free radiopaque agents, and was most reduced by 5 mg/mL DAP in the 14-day cultures.

CONCLUSIONS

MC-BaSO₄ or MC-ZrO₂ medicaments containing up to 5 mg/mL of DAP supported the proliferation and early osteogenic differentiation of DPSC. Low DAP concentrations and short culture times led to more favorable effects on ALP activity and mineral deposition by DPSC. The findings suggest that radiopaque agents added for the purpose of detecting whether medicaments occupy the full extent of the root canal may have clinical applications. Radiopaque antibiotic medicaments containing low DAP concentrations may be an alternative to Ca(OH)₂ for regenerative endodontic procedures.

Spectrophotometric analysis of discoloration and internal bleaching after use of different antibiotic pastes

OBJECTIVES

To investigate teeth's antibiotic-induced color differences after bleaching using two different techniques.

MATERIALS AND METHODS

One hundred twenty extracted maxillar human incisors were examined. The specimens were randomly divided into six groups, each receiving one of six antibiotic paste fillings: (1) triple antibiotic paste (TAP) with minocycline, (2) double antibiotic paste (DAP), (3) TAP with amoxicillin, (4) TAP with cefaclor, (5) TAP with doxycycline, and (6) no filling (control group). Spectrophotometric measurements were obtained at baseline and then during the first, second, and third weeks after paste placement. The specimens discolored by antibiotics pastes were randomly divided into two subgroups: (1) internal bleaching with hydrogen peroxide (H₂O₂₎ and (2) internal bleaching with H₂O₂ plus Nd-YAG laser irradiation. The ∆E value was calculated and analyzed using a two-way analysis of variance and post-hoc Tukey's test (α = 0.05).

RESULTS

The ∆E for all groups showed color differences exceeding the perceptibility threshold (∆E ˃ 3.7) at all time points except in the control and DAP groups. Minocycline-induced TAP showed the most severe coronal discoloration (32.42). When the ∆E was examined, thermo/photo bleaching (22.01 ± 8.23) caused more bleaching than walking bleaching (19.73 ± 5.73) at every time point (P = 0.19). No group returned to the original color after bleaching (P < 0.05).

CONCLUSIONS

Except for DAP, all antibiotic pastes caused discoloration. Internal bleaching with Nd-YAG laser can be useful for bleaching/removing this discoloration.

CLINICAL RELEVANCE

For clinically successful final appearances, understanding the effects of bleaching procedures on antibiotic paste discoloration is important.