Intracanal medicaments: evaluation of the antibacterial effects of chlorhexidine, metronidazole, and calcium hydroxide associated with three vehicles

Comparative evaluation of antimicrobial efficacy of different combinations of calcium hydroxide against Enterococcus faecalis

BACKGROUND

The study aims to compare the synergistic antibacterial efficacy of different combinations of calcium hydroxide as an intracanal medicament against E. faecalis.

MATERIAL AND METHODS

The current study included four hundred extracted human permanent mandibular premolar teeth. After complete chemo-mechanical preparation, the middle third of the root was sectioned using a rotary diamond disc and a total of 400 samples were obtained. The specimens were inoculated with E. faecalis for 21 days. After that, specimens were divided into five groups (n = 80) based on materials used for the disinfection of samples: Group I, calcium hydroxide alone; Group II, calcium hydroxide + 2% chlorhexidine gel; Group III, calcium hydroxide + 2% chitosan gel; Group IV, calcium hydroxide + 0.02% silver nanoparticle gel; Group V, calcium hydroxide + Bioactive glass S53P4. Dentin shavings from the apical third were obtained from the inner third of dentin were obtained using gates glidden no.1 to the apical depth, followed by no.2, 3, 4 and 5 analyzed for E. faecalis using the culture method. One-way analysis of variance (ANOVA) was used for data analysis, followed by post-hoc Tukey's test for multiple comparisons of means to check the difference in bacterial inhibition between the groups.

RESULTS

ANOVA results revealed a significant reduction of bacterial counts in all the groups compared (p < 0.001). Intergroup comparison showed maximum bacterial reduction (p < 0.001) with calcium hydroxide + bioactive glass S53P4 compared with other groups.

CONCLUSION

Synergistic effect of calcium hydroxide showed better bacterial reduction compared to calcium hydroxide alone. Among the combinations evaluated, calcium hydroxide with bioactive glass, found to be most effective compared to other groups.

Anti-bacterial efficacy of Aloe vera against E. Faecalis in comparison to other intracanal medicaments: A systematic review and meta-analysis

Introduction

This review article aims to evaluate the antibacterial efficacy of Aloe vera against Enterococcus faecalis (E. faecalis) in comparison to other intracanal medicaments by assessing experimental in-vitro studies associated with the objective, many of which performed bacterial inoculation on extracted human teeth or directly on laboratory petri dishes.

Materials & Methods

Publications from 2012 to 2022 were retrieved from databases, including PubMed, Scopus, and Cochrane Library, and they were screened against our inclusion criteria, leading to the incorporation of 18 studies into the systematic review and nine into the meta-analysis. Colony-forming units (CFUs) in the Aloe vera group were compared with saline, sodium hypochlorite (NaOCl), chlorhexidine (CHX), and calcium hydroxide (CaOH) using a meta-analysis (Stata software version 16.0), and forest plots were computed to record the sample size, mean and standard deviation value of the outcome CFU, and 95% confidence intervals.

Results

This systematic review indicates that Aloe vera demonstrates bactericidal properties that are higher than or similar to those of saline and CaOH, but CHX, NaOCl, and propolis exhibited higher antibacterial properties against E. faecalis than Aloe vera. In a meta-analysis, Aloe vera showed a non-significantly lower CFU count than CaOH and saline (p > 0.05), while Aloe vera had a higher CFU count than CHX and NaOCl (p > 0.05).

Conclusion

In summary, Aloe vera exhibits antibacterial capabilities against E. faecalis that are superior or equal to those of saline and CaOH, respectively, while CHX and NaOCl showed greater antibacterial efficacy against E. faecalis than Aloe vera (PROSPERO registration no. CRD42022314790).

Antimicrobial Efficacy of Morinda citrifolia, Nisin, and 2% Chlorhexidine Against Enterococcus faecalis: An In-Vitro Study

Aim

The aim of this study was to evaluate and compare the antimicrobial activity of 2% chlorhexidine gluconate (2% CHX), Morinda citrifolia (M. citrifolia), and nisin (NI) all in gel forms against Enterococcus faecalis (E. faecalis)-infected root canals.

Methodology

Forty single-rooted mandibular premolars extracted for orthodontic reasons were decoronated and chemomechanical preparation of the root canal was performed. After sterilization, the samples were inoculated with E. faecalis for one week and grouped according to the medicament used namely, saline as the control group (Group-A), 2% CHX (Group-B), M. citrifolia (Group-C), and NI (Group-D). After 7days of incubation, in order to evaluate the effectiveness of the intracanal medicaments on the canal wall and its radicular dentin, the specimens dentin chips were retrieved and inoculated on brain heart infusion (BHI) blood agar plates from each tube and incubated at 37^°C for 24 hours to obtain bacterial colony forming unit (CFU) count. The data was statistically analyzed using one-way ANOVA test and multiple comparisons among different groups were complemented by post hoc Tukey test.

Results

The CFU count indicating the number of viable bacterial colonies was found to be highest in Group-A (saline). Group-B (CHX 2%) showed the least CFUs followed by Group-D (NI) and Group-C (M. citrifolia).

Conclusion

In an attempt to overcome the disadvantages and toxic effects of a few commercially available intracanal medicaments and irrigants, the present study was aimed at using herbal extracts to evaluate and compare their antimicrobial efficacy with the commercially available medicaments against E. faecalis. Nisin was an effective antimicrobial agent and its action was found to be comparable with CHX.

How Adding Chlorhexidine or Metallic Nanoparticles Affects the Antimicrobial Performance of Calcium Hydroxide Paste as an Intracanal Medication: An In Vitro Study

The aim of our study was to explore the potential value of metallic (Ag, Cu, and Zn) salts, polymer/metallic nanoparticles, and chlorhexidine (CHX) for improving the antimicrobial activity of calcium hydroxide (CH) against E. faecalis and C. albicans, associated with persistent endodontic infections. A first screening was performed by determining minimum inhibitory/bactericidal concentrations (MIC/MBC). Antimicrobial activity of the CH paste mixed with metallic salts, chitosan or cyclodextrin polymer metallic nanoparticles was compared to the antimicrobial activity of CH paste alone and CH + CHX using a time-kill kinetics assay. The effect of the antimicrobials on the rheological and the key mechanical properties were also examined. Copper and zinc were discarded because of their MIC/MBC values and silver because of its kill time curve profile. Except for a slower setting time after 24 h and a higher weight loss after 1 week of incubation, the mechanical behavior of the CH paste was unaffected by the addition of CHX. Polymeric/metallic nanoparticles failed to potentiate the antimicrobial effect of CH. By contrast, CHX increased this effect and thus could help eradicate E. faecalis associated with persistent root canal infections without altering the desired key physical properties of the CH paste.

Multicomponent Peptide Hydrogels as an Innovative Platform for Cell-Based Tissue Engineering in the Dental Pulp

In light of the increasing levels of antibiotic resistance, nanomaterials and novel biologics are urgently required to manage bacterial infections. To date, commercially available self-assembling peptide hydrogels have not been studied extensively for their ability to inhibit micro-organisms relevant to tissue engineering sites such as dental root canals. In this work, we assess the biocompatibility of dental pulp stem/stromal cells with commercially available multicomponent peptide hydrogels. We also determine the effects of dental pulp stem/stromal cell (DPSC) culture in hydrogels on growth factor/cytokine expression. Furthermore, to investigate novel aspects of self-assembling peptide hydrogels, we determine their antimicrobial activity against the oral pathogens Staphylococcus aureus, Enterococcus faecalis, and Fusobacterium nucleatum. We show that self-assembling peptide hydrogels and hydrogels functionalized with the adhesion motif Arg-Gly-Asp (RGD) are biocompatible with DPSCs, and that cells grown in 3D hydrogel cultures produce a discrete secretome compared with 2D-cultured cells. Furthermore, we show that soluble peptides and assembled hydrogels have antimicrobial effects against oral pathogens. Given their antibacterial activity against oral pathogens, biocompatibility with dental pulp stem/stromal cells and enhancement of an angiogenic secretome, multicomponent peptide hydrogels hold promise for translational use.

Nematode-Associated Bacteria: Production of Antimicrobial Agent as a Presumptive Nominee for Curing Endodontic Infections Caused by Enterococcus faecalis

Xenorhabdus and/or Photorhabdus bacteria produce antibacterial metabolites to protect insect cadavers against food competitors allowing them to survive in nature with their nematode host. The effects of culture supernatant produced by Xenorhabdus and Photorhabdus spp. were investigated against the multidrug-resistant dental root canal pathogen Enterococcus faecalis. The efficacy of seven different cell-free supernatants of Xenorhabdus and Photorhabdus species against E. faecalis was assessed with overlay bioassay and serial dilution techniques. Additionally, time-dependent inactivation of supernatant was evaluated. Among the seven different bacterial species, X. cabanillasii produced the strongest antibacterial effects. Loss of bioactivity in a phosphopantetheinyl transferase-deficient mutant of X. cabanillasii indicated that this activity is likely based on non-ribosomal peptide synthetases (NRPSs) or polyketide synthases (PKSs). Subsequent in silico analysis revealed multiple possible biosynthetic gene clusters (BGCs) in the genome of X. cabanillasii including a BGC homologous to that of zeamine/fabclavine biosynthesis. Fabclavines are NRPS-derived hexapeptides, which are connected by PKS-derived malonate units to an unusual polyamine, also PKS-derived. Due to the known broad-spectrum bioactivity of the fabclavines, we generated a promoter exchange mutant in front of the fabclavine-like BGC. This leads to over-expression by induction or a knock-out by non-induction which resulted in a bioactive and non-bioactive mutant. Furthermore, MS and MS² experiments confirmed that X. cabanillasii produces the same derivatives as X. budapestensis. The medicament potential of 10-fold concentrated supernatant of induced fcl promoter exchanged X. cabanillasii was also assessed in dental root canals. Calcium hydroxide paste, or chlorhexidine gel, or fabclavine-rich supernatant was applied to root canals. Fabclavine-rich supernatant exhibited the highest inactivation efficacy of ≥3 log₁₀ steps CFU reduction, followed by calcium hydroxide paste (≤2 log₁₀ step). The mean percentage of E. faecalis-free dental root canals after treatment was 63.6, 45.5, and 18.2% for fabclavine, calcium hydroxide, and chlorhexidine, respectively. Fabclavine in liquid form or preferably as a paste or gel formulation is a promising alternative intracanal medicament.

Antimicrobial activity and pH measurement of calcium silicate cements versus new bioactive resin composite restorative material

Background

The purpose of this in vitro study is to compare the antimicrobial effect and pH of two calcium silicate cements Mineral trioxide aggregate high plasticity (Angelus PR, Brazil) and iRoot BP Plus (BioCeramix Inc., Vancouver, BC, Canada) and new bioactive restorative resin composite restorative material (ACTIVA, MA, Pulpdent, USA) against aerobic bacteria, strictly anaerobic bacteria and a yeast by using an agar diffusion test.

Methods

The materials were tested immediately after manipulation and were applied to the agar plates. Sodium hypochlorite (NaOCl) 5.25% was used as a positive control group. The dry filter paper acted as a negative control group for this study. The size of the inhibition zone for each material was measured after 12, 24 and 48 h. At the time of pH measurement; materials were prepared, crushed then dispersed in distilled water.

Results

The one-way Anova test revealed that iRoot BP Plus significantly showed superior antimicrobial efficacy compared to MTA-HP against the following species; Staphylococcus aureus, Streptococcus mutans, Enterococcus faecalis, Enterococcus faecium, Peptostreptococcus anaerobius and Candida albicans (P < 0.05). All of the tested materials did not show any antimicrobial effect against Porphyromonas gingivalis and Actinomyces israelii. The new bioactive resin composite material (ACTIVA) showed the least antimicrobial activity against the previously mentioned microorganisms except E. faecalis. NaOCl significantly showed the highest antimicrobial activity among the test group (P < 0.05). iRoot BP Plus was more alkaline (pH 12.1 ± 0.14/ 11.9 ± 0.25) in comparison to MTA-HP (pH 11.6 ± 0.16/ 11.2 ± 0.10) while ACTIVA was slightly acidic (pH 5.4 ± 0.09/ 6.5 ± 0.08).

Conclusions

According to the findings of this study, it was concluded that calcium silicate- based cements showed a potential antimicrobial activity mainly due to its high alkalinity. The new bioactive resin composite restorative material exhibits less antimicrobial activity due to its resinous ingredients and slightly acidic nature. Antimicrobial effect of calcium silicate cements against strictly anaerobic bacterial species is still questionable.

In vitro antimicrobial activity of different electrochemically-activated solutions on enterococcus faecalis

Purpose

The aim of this in vitro study was to assess and compare the antimicrobial efficacy of different electrochemically-activated solutions (ECA) and contemporary irrigants, in root canals infected with Enterococcus faecalis, used with or without EndoActivator (EA).

Materials and methods

A hundred single-rooted human teeth were prepared. Ninety of the root segments were infected with E. faecalis for four weeks, and divided into eight test groups (n = 10) (four with and four without EA sonication) and a positive control (n = 10). The irrigants tested were electrochemically-activated solutions produced by the Medilox® (ECA-MX) and Envirolyte® devices (ECA-EN), 2% CHX and 2.5% NaOCl. The root specimens were irrigated with 5 mL of the test solution, with additional sonic agitation applied to the EA groups. The dentine samples that were obtained from the walls were cultured, and the antibacterial efficacy was evaluated by counting the colony-forming units.

Results

The ECA-EN, 2.5% NaOCl and 2% CHX were more effective than the ECA-MX (p<0.05) with the addition of EA sonication, showing no statistical difference in the elimination of E. faecalis.

Conclusion

The ECA-EN shows potential as an endodontic irrigant, while EA usage gives no benefit in reducing bacteria from root canals.

Evaluation of postoperative pain in infected root canals after using double antibiotic paste versus calcium hydroxide as intra-canal medication: A randomized controlled trial

Background: Postoperative pain is defined as pain of any degree after initiation of endodontic treatment either intra-appointment or post-obturation and is considered an undesirable occurrence for both patient and dentist. It was suggested that bacterial injury is probably the major cause of pain. Intra-canal medicaments are widely used to kill any bacteria surviving after instrumentation and irrigation. The aim of this study was to assess the ability of double antibiotic paste versus calcium hydroxide used as intra-canal medication in reducing postoperative pain. Methods: 36 patients with single rooted necrotic premolars with apical periodontitis were randomly assigned into two groups according to the intra-canal medication used: calcium hydroxide group (CH) and double antibiotic paste group (DAP). Preoperative pain was recorded using numerical rating scale. After isolation, access cavity was performed followed by chemico-mechanical preparation using rotary Race files with 2.5% sodium hypochlorite irrigation. Subsequently, intra-canal medication was placed and postoperative pain was recorded at 6, 12, 24 and 48 hours postoperatively. Results: There was no statistically significant difference between both groups. Both groups resulted in an increase in median pain value from preoperative to 6 hours postoperative, followed by gradual decrease from 6 hours to 12, 24, 48 hours postoperatively with statistically significant difference. When comparing both groups, DAP group showed lower postoperative pain values than CH group at 12 and 24 hours, but this was not statistically significant. Conclusion: The use of intra-canal medication in necrotic teeth with apical periodontitis was efficient in reducing postoperative pain regardless of type of intra-canal medication used. Trial registration: PACTR201605001482394 (Date: 22 nd February 2016).

Analysis of pH and release of calcium of association between melaleuca alternifolia oil and calcium hydroxide

Abstract Introduction The use of intracanal medications with antimicrobial properties is essential for decontaminating root canals during endodontic treatment. Calcium hydroxide is used for this because of its excellent properties. Melaleuca alternifolia oil has shown medicinal importance by demonstrating antifungal and bactericidal action against proven human pathogens. Objective To evaluate the physical and chemical aspects such as pH and calcium release, of Melaleuca alternifolia oil associated with calcium hydroxide, during different time intervals. Material and method Calcium hydroxide powder was added to vehicles to reach a concentration of 72mg / 0.1mL. Three groups were formed: Group I: Calcium Hydroxide + Distilled Water; Group II: Calcium hydroxide + Propylene Glycol; Group III: Calcium hydroxide + Melaleuca oil. The pH of each group was measured after time intervals of 10 minutes; 24 and 48 hours; 7, 15 and 30 days after tooling by a pH meter. Calcium release was analyzed by atomic absorption spectrometry equipped with a calcium hollow cathode lamp. Data were statistically analyzed by using the Kruskall-Wallis and Dunn test. Result Group II showed high pH, similar to group III that remained uniform at 15 and 30 days. Calcium release that began after 24 hours, was similar in Groups II and III, and showed a peak release in 48 hours. Conclusion The association of Melaleuca oil with calcium hydroxide showed good results in the pH and calcium release analyses, and showed action similar to that of propylene glycol + calcium hydroxide.

Efficacy of Various Intracanal Medicaments in Human Primary Teeth with Necrotic Pulp against Candida Biofilms: An in vivo Study

Background

Candida has been associated with cases of secondary and persistent root canal infections. The purpose of this study was to evaluate and compare the effectiveness of commonly used intracanal medicament against Candida biofilms found in root canals of human primary teeth with necrotic pulp.

Materials and methods

Pulp canals of 45 single-rooted primary maxillary anterior teeth with pulp necrosis in 34 children were included in the study. They were divided into three groups of 15 samples each - group I: Ca(OH)₂ (calcium hydroxide); group II: 1% chlorhexidine gel (CHX); and group III: 1% metronidazole gel. Bacterial count was obtained from each tooth at two different stages: (1) after instrumentation, and (2) after placement of the medication. Statistical analysis using the Statistical Package for the Social Sciences version 10.0 software program (Inc., Chicago, IL, USA) with Wilcoxon signed rank test after grouping the samples was performed.

Results

Ca(OH)₂, 1% CHX gel, and 1% metronidazole gel were ineffective in completely eliminating Candida biofilms from root canal of human primary teeth with necrotic pulp.

Conclusion

None of the commonly used intracanal medicaments, i.e., Ca(OH)₂, 1% CHX gel, and 1% metronidazole gel, was effective in completely eliminating Candida biofilm from root canal of human primary teeth with necrotic pulp. Ineffectiveness of these medicaments against Candida has opened new door of research regarding the use of suitable intracanal medicaments against single and multispecies biofilms.

How to cite this article

Paikkatt JV, Sreedharan S, Philomina B, Kannan VP, Santhakumar M, Kumar TVA. Efficacy of Various Intracanal Medicaments in Human Primary Teeth with Necrotic Pulp against Candida Biofilms: An in vivo Study. Int J Clin Pediatr Dent 2017;10(1):45-48.

Vitality of Enterococcus faecalis inside dentinal tubules after five root canal disinfection methods

Aim:

To compare the vitality of Enterococcus faecalis within dentinal tubules after subjected to five root canal disinfection methods.

Materials and Methods:

Dentin blocks (n = 60) were colonized with E. faecalis. After 4 weeks of incubation, the dentin blocks were divided into one control and five test groups (n = 10 each). The root canals of test groups were subjected to one of the disinfection methods, namely, normal saline (NS), sodium hypochlorite (NaOCl), chlorhexidine digluconate (CHX), neodymium-doped yttrium aluminum garnet (Nd: YAG) laser, and diode laser. The effect of disinfection methods was assessed by LIVE/DEAD BacLight stain under the confocal laser scanning microscopy to determine the “zone of dead bacteria” (ZDB). Mean values were calculated for ZDB and the difference between groups was established.

Results:

Penetration of E. faecalis was seen to a depth of >1000 μm. Viable bacteria were detected with NS irrigation. NaOCl and CHX showed partial ZDB. When the root canals were disinfected with Nd: YAG and diode lasers, no viable bacteria were found.

Conclusion:

E. faecalis has the ability to colonize inside dentinal tubules to a depth of >1000 μm. In contrast to conventional irrigants, both Nd: YAG and diode lasers were effective in eliminating the vitality of E. faecalis. NS, NaOCl, and CHX showed viable bacteria remaining in dentinal tubules.

Effectiveness of N-acetyl cysteine, 2% chlorhexidine, and their combination as intracanal medicaments on Enterococcus faecalis biofilm

Aim:

The purpose of this study was to evaluate the antibacterial efficacies of 2% chlorhexidine (CHX), N-acetyl cysteine (NAC) and assess their synergistic or antagonist action as intracanal medicament.

Materials and Methods:

Agar diffusion test was performed with 2% CHX, NAC, and their combination against E. faecalis planktonic cells. The diameters of the zones of bacterial inhibition were measured and recorded for each solution. The assay was further extended to 2 weeks old E. faecalis dentinal biofilm. Sixteen freshly extracted teeth were vertically sectioned into two halves resulting in a total of 32 samples. The samples were inoculated with bacterial suspension and incubated at 37°C for 2 weeks for biofilm formation. The samples were then divided into four experimental groups with 8 samples in each group. The samples were gently washed in saline and placed in culture wells containing the test solutions, i.e., 2% CHX, NAC, a combination of 2% CHX and NAC in 1:1 ratio, and a control group containing saline. The biofilm formed on the root canal surface were removed with a sterile scalpel and inoculated on blood agar plates to check for the formation of E. faecalis colonies.

Statistical Analysis:

For agar diffusion test, data were analyzed statistically using one-way analysis of variance and then by post-hoc Scheffe's test to compare the antimicrobial efficacy between the groups. Statistical analysis was not done for the cultures obtained from the biofilm as there was no growth in all the three test groups except the control group, i.e., saline.

Results:

In agar diffusion test, among the three groups tested, 2% CHX and NAC showed almost equal zones of inhibition whereas maximum inhibition was shown by a combination of NAC and 2% CHX suggesting a synergistic action. The results obtained were highly significant (P < 0.001) for the combination of medicament when compared to individual test group. In culture analysis, which was done for the biofilm, no growth was observed in all the three test groups. The results obtained were biologically significant but statistically insignificant.

Conclusion:

NAC has almost equal antimicrobial property as 2% CHX whereas their combination showed a synergistic action.

Dentinal Tubule Disinfection with Propolis & Two Extracts of Azadirachta indica Against Candida albicans Biofilm Formed on Tooth Substrate

Aim:

This study evaluates the disinfection of dentinal tubules using Propolis, Azadirachta indica (alcoholic and aqueous extracts), 2% chlorhexidine gel and calcium hydroxide against Candida albicans biofilm formed on tooth substrate.

Materials & Method:

One hundred and five human teeth were infected with Candida albicans for 2 days. Samples were divided into 7 groups. Group I- Propolis, Group II- Alcoholic extract of Azadirachta indica, Group III- Aqueous extract of Azadirachta indica, Group IV- 2% Chlorhexidine, Group V- Calcium hydroxide, Group VI- Ethanol and Group VII- Saline (negative control). At the end of 1,3 and 5 days, the antimicrobial efficacy of medicaments against Candida albicans was assessed at the depths of 200 µm and 400 µm.

Results:

The overall percentage inhibition of fungal growth (at 200 µm and 400 µm depth) was 99.2% with 2% chlorhexidine gel. There was no statistical difference between propolis, alcoholic extract of Azadirachta indica (neem) and 2% chlorhexidine.

Conclusion:

Propolis and alcoholic extract of Azadirachta indica performed equally well as that of 2% Chlorhexidine.

Antibacterial effect of calcium hydroxide combined with chlorhexidine on Enterococcus faecalis: a systematic review and meta-analysis

Objective

Enterococcus faecalis (E. faecalis) is the most frequently isolated strain in failed endodontic therapy cases since it is resistant to calcium hydroxide (CH). Whether a combination of CH and chlorhexidine (CHX) is more effective than CH alone against E. faecalis is a matter of controversy. Thus, the aim of this study was to conduct a systematic review and meta-analysis of the literature.

Material and Methods

A comprehensive search in PubMed, EMbase, EBSCOhost, The Cochrane Library, SciELO, and BBO databases, Clinical trials registers, Open Grey, and conference proceedings from the earliest available date to February 1, 2013 was carried out and the relevant articles were identified by two independent reviewers. Backward and forward search was performed and then inclusion and exclusion criteria were applied. The included studies were divided into "comparisons" according to the depth of sampling and dressing period of each medicament. Meta-analysis was performed using Stata software 10.0. The level of significance was set at 0.05.

Results

Eighty-five studies were retrieved from databases and backward/forward searches. Fortyfive studies were considered as relevant (5 in vivo, 18 in vitro, 18 ex vivo, and 4 review articles). Nine studies were included for meta-analysis. Inter-observer agreement (Cohen kappa) was 0.93. The included studies were divided into 21 comparisons for meta-analysis. Chi-square test showed the comparisons were heterogeneous (p<0.001). Random effect model demonstrated no significant difference between CH/CHX mixture and CH alone in their effect on E. faecalis (p=0.115).

Conclusions

According to the evidence available now, mixing CH with CHX does not significantly increase the antimicrobial activity of CH against E. faecalis. It appears that mixing CH with CHX does not improve its ex vivo antibacterial property as an intracanal medicament against E. faecalis. Further in vivo studies are necessary to confirm and correlate the findings of this study with the clinical outcomes.

In vitro evaluation of antimicrobial activity of different Gutta-percha points and calcium hydroxide pastes

Purpose:

To evaluate the antimicrobial activity of different compositions of Gutta-percha points and calcium hydroxide (Ca(OH)₂) pastes, used in endodontic therapy.

Materials and Methods:

The evaluated material consisted of Gutta-percha points containing Ca(OH)₂, Gutta-percha points containing chlorhexidine (Chx), conventional Gutta-percha points and Ca(OH)₂ pastes. Antimicrobial properties of Chx and CaOH paste are compared with CaOH points. Antimicrobial tests included three species of microorganisms: Escherichia coli (ATCC 25923), Staphylococcus aureus (ATCC 25922) Pseudomonas aeruginosa (ATCC BAA-427), the agar disc diffusion method was employed. The plates were kept at room temperature for 2 h for prediffusion and then incubated at 37°C for 24 h. Zones of inhibition were measured.

Results and Conclusion:

All microbial species used in the study were inhibited by the Gutta-percha points containing Chx and by the Ca(OH)₂ pastes, no antimicrobial activity was observed for the other groups (conventional Gutta-percha and Ca(OH)₂ group).

Antimicrobial effect of calcium hydroxide as an intracanal medicament in root canal treatment: a literature review - Part I. In vitro studies

The goal of endodontic treatment is the prevention and control of pulpal and periradicular infections. Calcium hydroxide (Ca(OH)2) has been widely used in endodontics as an intracanal medicament to eliminate the remaining microorganisms after chemomechanical preparation. The purpose of this article is to review the antimicrobial properties of Ca(OH)2 as an intracanal medicament in root canal treatment. The first part of this review details the characteristics of Ca(OH)2 and summarizes the results of in vitro studies related to its antimicrobial effect. The antimicrobial effect of Ca(OH)2 results from the release of hydroxyl ions when it comes into contact with aqueous fluids. Ca(OH)2 has a wide range of antimicrobial effects against common endodontic pathogens, but is less effective against Enterococcus faecalis and Candida albicans. The addition of vehicles or other agents might contribute to the antimicrobial effect of Ca(OH)2.

Effectiveness of curcumin against Enterococcus faecalis biofilm

OBJECTIVES

To evaluate the antimicrobial efficacy of curcumin against Enterococcus faecalis biofilm formed on tooth substrate in vitro. Sodium hypochlorite (NaOCl) and chlorhexidine (CHX) served as standards for comparison.

MATERIALS AND METHODS

Biofilms of E.faecalis were formed on instrumented, extracted human teeth (n = 96). At the end of the 2nd day, 2nd and 8th weeks, specimens were treated for 30 min with one of the test solutions or saline (control) and the surviving colony-forming units (CFU/mL) was recorded. Results were analyzed by Kruskal-Wallis test and Dunnet test for pair-wise comparison with Bonferroni correction (p = 0.05).

RESULTS

Only NaOCl showed complete eradication of bacteria at all time periods. In the 2-day and 2nd week biofilms, curcumin and NaOCl showed complete inhibition, which was significantly lower than the CFU recovered in the CHX and saline groups (p < 0.05). In 8 week biofilms, samples treated with curcumin showed 553 ± 137.6 CFU/mL, which was significantly higher than NaOCl (0 CFU/mL), but significantly lower than CHX (2551 ± 129.8) and saline control (1.42 × 1011 ± 2.12 × 1010; p < 0.05).

CONCLUSIONS

Sodium hypochlorite (3%) showed maximum antibacterial activity against E.faecalis biofilm formed on the tooth substrate, followed by curcumin and CHX. Considering the potential for undesirable properties of NaOCl, the use of herbal alternatives in endodontics might prove to be advantageous.

Bioactive nanofibrous scaffolds for regenerative endodontics

Here we report the synthesis, materials characterization, antimicrobial capacity, and cytocompatibility of novel antibiotic-containing scaffolds. Metronidazole (MET) or Ciprofloxacin/(CIP) was mixed with a polydioxanone (PDS)polymer solution at 5 and 25 wt% and processed into fibers. PDS fibers served as a control. Scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), tensile testing, and high-performance liquid chromatography (HPLC) were used to assess fiber morphology, chemical structure, mechanical properties, and drug release, respectively. Antimicrobial properties were evaluated against those of Porphyromonas gingivalis/Pg and Enterococcus faecalis/Ef. Cytotoxicity was assessed in human dental pulp stem cells (hDPSCs). Statistics were performed, and significance was set at the 5% level. SEM imaging revealed a submicron fiber diameter. FTIR confirmed antibiotic incorporation. The tensile values of hydrated 25 wt% CIP scaffold were significantly lower than those of all other groups. Analysis of HPLC data confirmed gradual, sustained drug release from the scaffolds over 48 hrs. CIP-containing scaffolds significantly (p < .00001) inhibited biofilm growth of both bacteria. Conversely, MET-containing scaffolds inhibited only Pg growth. Agar diffusion confirmed the antimicrobial properties against specific bacteria for the antibiotic-containing scaffolds. Only the 25 wt% CIP-containing scaffolds were cytotoxic. Collectively, this study suggests that polymer-based antibiotic-containing electrospun scaffolds could function as a biologically safe antimicrobial drug delivery system for regenerative endodontics.

Dentinal tubule disinfection with 2% chlorhexidine, garlic extract, and calcium hydroxide against Enterococcus faecalis by using real-time polymerase chain reaction: In vitro study

AIM

To compare the efficacy of garlic extract with 2% chlorhexidine (CHX) and calcium hydroxide Ca(OH)2 in disinfection of dentinal tubules contaminated with Enterococcus faecalis by using real-time polymerase chain reaction (PCR).

MATERIALS AND METHODS

Agar diffusion test was done to evaluate the minimum inhibitory concentration of garlic extract against E. faecalis. Forty human extracted mandibular premolar teeth were selected for this study, access cavity was prepared and cleaning and shaping was done. Middle third of the root was cut using a rotary diamond disc. The teeth specimens were inoculated with E. faecalis for 21 days. Specimens were divided into four groups---Group 1: 2% CHX, Group 2: Garlic extract, Group 3: Ca(OH)2, and Group 4: Saline (negative control). The intracanal medicaments were packed inside the tooth specimens and incubated for 5 days. The dentinal chips were collected at 400 μm depth using a Gates-Glidden drill, following which DNA isolation was done. The specimens were analyzed using real-time PCR. The results were then statistically analyzed using one-way analysis of variance, followed by post hoc Tukey's honestly significant difference (HSD) multiple comparison of means.

RESULTS

Threshold cycle (Ct) values of 2% CHX was found to be 32.4, garlic extract to be 27.5, and Ca(OH)2 to be 25.6.

CONCLUSION

A total of 2% CHX showed the maximum efficacy against E. faecalis, followed by garlic extract and Ca(OH)2.

Antibacterial action of calcium hydroxide vehicles and calcium hydroxide pastes

AIM

To evaluate the in vitro action of vehicles alone and with calcium hydroxide against different bacterial species.

METHODS

Agar plates were inoculated with the microbial suspensions, and wells were made and filled with the calcium hydroxide pastes and the vehicles used to prepare the pastes. The zones of inhibited bacterial growth were recorded, and the resulting measurements were statistically analyzed.

RESULTS

Enterococcus faecalis was the most resistant microorganism to all medicaments. Calcium hydroxide + p-monochlorophenol; calcium hydroxide + p-monochlorophenol-propylene glycol pastes; and p-monochlorophenol, p-monochlorophenol-propylene glycol, and chlorhexidine gluconate gel alone showed the largest zones of inhibition against all the tested microorganisms.

CONCLUSIONS

The vehicle used to prepare the calcium hydroxide paste might contribute to its antibacterial action. Chlorhexidine gluconate gel used alone, and camphorated p-monochlorophenol and camphorated p-monochlorophenol-propylene glycol as vehicles of calcium hydroxide, could be recommended, in an antimicrobial sense.

Chlorhexidine in Endodontics

Chemical auxiliary substances (CAS) are essential for a successful disinfection and cleanness of the root canals, being used during the instrumentation and if necessary, as antimicrobial intracanal medicaments. Different CAS have been proposed and used, among which sodium hypochlorite (NaOCl), chlorhexidine (CHX), 17% EDTA, citric acid, MTAD and 37% phosphoric acid solution. CHX has been used in Endodontics as an irrigating substance or intracanal medicament, as it possesses a wide range of antimicrobial activity, substantivity (residual antimicrobial activity), lower cytotoxicity than NaOCl whilst demonstrating efficient clinical performance, lubricating properties, rheological action (present in the gel presentation, keeping the debris in suspension); it inhibits metalloproteinase, is chemically stable, does not stain cloths, it is odorless, water soluble, among other properties. CHX has been recommended as an alternative to NaOCl, especially in cases of open apex, root resorption, foramen enlargement and root perforation, due to its biocompatibility, or in cases of allergy related to bleaching solutions. The aim of this paper is to review CHX's general use in the medical field and in dentistry; its chemical structure, presentation form and storage; mechanism of action; antimicrobial activity including substantivity, effects on biofilms and endotoxins, effects on coronal and apical microbial microleakage; tissue dissolution ability; interaction with endodontic irrigants; effects on dentin bonding, metalloproteinases and collagen fibrils; its use as intracanal medicament and diffusion into the dentinal tubules; its use as disinfectant agent of obturation cones; other uses in the endodontic therapy; and possible adverse effects, cytotoxicity and genotoxicity.

Antimicrobial activity of calcium hydroxide and chlorhexidine on intratubular Candida albicans

This study investigated the efficacy of calcium hydroxide and chlorhexidine gel for the elimination of intratubular Candida albicans (C. albicans). Human single-rooted teeth contaminated with C. albicans were treated with calcium hydroxide, 2% chlorhexidine gel, calcium hydroxide plus 2% chlorhexidine gel, or saline (0.9% sodium chloride) as a positive control. The samples obtained at depths of 0–100 and 100–200 µm from the root canal system were analyzed for C. albicans load by counting the number of colony forming units and for the percentage of viable C. albicans using fluorescence microscopy. First, the antimicrobial activity of calcium hydroxide and the 2% chlorhexidine gel was evaluated by counting the number of colony forming units. After 14 days of intracanal medication, there was a significant decrease in the number of C. albicans colony forming units at a depth of 0–100 µm with chlorhexidine treatment either with or without calcium hydroxide compared with the calcium hydroxide only treatment. However, there were no differences in the number of colony forming units at the 100–200 µm depth for any of the medications investigated. C. albicans viability was also evaluated by vital staining techniques and fluorescence microscopy analysis. Antifungal activity against C. albicans significantly increased at both depths in the chlorhexidine groups with and without calcium hydroxide compared with the groups treated with calcium hydroxide only. Treatments with only chlorhexidine or chlorhexidine in combination with calcium hydroxide were effective for elimination of C. albicans.

Effect of the smear layer in the removal of calcium hydroxide from root canal walls

Background:

The aim of this study was to investigate whether the smear layer influences the removal of calcium hydroxide from the root canal with manual or rotary instruments.

Materials and Methods:

The root canals of 48 freshly extracted single-rooted maxillary incisors were prepared to apical size 40 (n=40) and finally irrigated with sodium hypochlorite (group A), or ethylene diamine tetra acetic acid (EDTA) followed by sodium hypo chlorite (group B). 20 teeth were assigned to each group, while the remaining eight teeth served as positive and negative controls. Each group was divided into two subgroups of 10 teeth (subgroup I - calcium hydroxide was removed with master apical file; subgroup II - with profile file); and, in all removal procedures, citric acid was used for irrigation. The percentage of calcium hydroxide- [Ca(OH)₂] coated surface area was calculated by image processing analysis.

Results:

Considering the root canal as a whole, the removal of Ca(OH)₂ from the dentinal walls in group B showed significantly better results (P<0.05) as compared to group A.

Conclusions:

Under the conditions of this study, it can be concluded that the smear layer is important in the removal of calcium hydroxide.

Synthesis of partial stabilized cement-gypsum as new dental retrograde filling material

The study describes the sol-gel synthesis of a new dental retrograde filling material partial stabilized cement (PSC)-gypsum by adding different weight percentage of gypsum (25% PSC+75% gypsum, 50% PSC+50% gypsum and 75% PSC+25% gypsum) to the PSC. The crystalline phase and hydration products of PSC-gypsum were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM) analysis. The handling properties such as setting time, viscosity, tensile strength, porosity and pH, were also studied. The XRD and microstructure analysis demonstrated the formation of hydroxyapatite and removal of calcium dihydrate during its immersion in simulated body fluid (SBF) on day 10 for 75% PSC+25% gypsum. The developed PSC-gypsum not only improved the setting time but also greatly reduced the viscosity, which is very essential for endodontic surgery. The cytotoxic and cell proliferation studies indicated that the synthesized material is highly biocompatible. The increased alkaline pH of the PSC-gypsum also had a remarkable antibacterial activity.

Accuracy of Root ZX in teeth with simulated root perforation in the presence of gel or liquid type endodontic irrigant

Objectives

To evaluate the accuracy of the Root ZX in teeth with simulated root perforation in the presence of gel or liquid type endodontic irrigants, such as saline, 5.25% sodium hypochlorite (NaOCl), 2% chlorhexidine liquid, 2% chlorhexidine gel, and RC-Prep, and also to determine the electrical conductivities of these endodontic irrigants.

Materials and Methods

A root perforation was simulated on twenty freshly extracted teeth by means of a small perforation made on the proximal surface of the root at 4 mm from the anatomic apex. Root ZX was used to locate root perforation and measure the electronic working lengths. The results obtained were compared with the actual working length (AWL) and the actual location of perforations (AP), allowing tolerances of 0.5 or 1.0 mm. Measurements within these limits were considered as acceptable. Chi-square test or the Fisher's exact test was used to evaluate significance. Electrical conductivities of each irrigant were also measured with an electrical conductivity tester.

Results

The accuracies of the Root ZX in perforated teeth were significantly different between liquid types (saline, NaOCl) and gel types (chlorhexidine gel, RC-Prep). The accuracies of electronic working lengths in perforated teeth were higher in gel types than in liquid types. The accuracy in locating root perforation was higher in liquid types than gel types. 5.25% NaOCl had the highest electrical conductivity, whereas 2% chlorhexidine gel and RC-Prep gel had the lowest electrical conductivities among the five irrigants.

Conclusions

Different canal irrigants with different electrical conductivities may affect the accuracy of the Root ZX in perforated teeth.

Short-term antimicrobial properties of mineral trioxide aggregate with incorporated silver-zeolite

The purpose of this in vitro study was to determine whether adding silver-zeolite (SZ) to mineral trioxide aggregate (MTA) would enhance the antimicrobial activity of MTA against Staphylococcus aureus (ATCC #25923), Enterococcus faecalis (ATCC #29212), Escherichia coli (ATCC#25922), Pseudomonas aeruginosa (ATCC #27853), Candida albicans (ATCC #90028), Porphyromonas gingivalis (ATCC #33277), Actinomyces israelii (ATCC #12102), and Prevotella intermedia (ATCC# 15032). SZ was added at 0.2% and 2% mass fraction concentration to MTA powder. The control group was MTA powder with no SZ. The antimicrobial effect test was accomplished by placing freshly mixed MTA specimens on agar plates inoculated with microorganisms and comparing the zones of inhibition at 24, 48, and 72 h. The amounts of silver ion release from MTA specimens were measured with atomic absorption spectrophotometry at 10-min, 24-, 48-, and 72-h periods. The pH of MTA specimens was measured with a pH meter at 10-min, 24-, 48-, and 72-h periods. MTA with 2% and 0.2% SZ specimens showed inhibitory effects on some microorganisms at all time periods, whereas no antimicrobial activity showed for P. intermedia and A. israelii. MTA without SZ inhibited C. albicans, E. Coli, and P. intermedia. The highest silver release was detected in 2% SZ MTA at 24 h. The incorporation of SZ may enhance the antimicrobial activity of MTA.

Dentinal tubule disinfection with 2% chlorhexidine gel, propolis, morinda citrifolia juice, 2% povidone iodine, and calcium hydroxide

AIM

To investigate the antimicrobial activity of 2% chlorhexidine gel, propolis, Morinda citrifolia juice (MCJ), 2% povidone Iodine (POV-I), and calcium hydroxide on Enterococcus faecalis-infected root canal dentine at two different depths (200 microm and 400 microm) and three time intervals (day 1, 3 & 5).

METHODOLOGY

One hundred and eighty extracted human teeth were infected for 21 days with E. faecalis. Samples were divided into six groups. Group I (Saline) (Negative control), Group II (Propolis), Group III (MCJ), Group IV (2% Povidone Iodine), Group V (2% Chlorhexidine Gel), Group VI (Calcium hydroxide). At the end of 1, 3, and 5 days, the remaining vital bacterial population was assessed. Dentine shavings were collected at two depths (200 microm and 400 microm), and total numbers of colony forming units were determined. The values were analysed statistically with one-way analysis of variance followed by Tukey multiple comparison test. The paired t-test was used to check for differences in growth at different time intervals within groups and for differences at the two depths (P < 0.01)

RESULTS

The number of colony-forming units was statistically significant in all groups compared to the control group (Saline). Group V (chlorhexidine gluconate) (100%) produced better antimicrobial efficacy followed by 2% POV-I (87%), propolis (71%), MCJ (69%), and calcium hydroxide (55%). There was no significant difference between propolis and MCJ and no significant difference between data at 200 microm and 400 microm.

CONCLUSION

Propolis and MCJ were effective against E. faecalis in dentine of extracted teeth.

Conventional endodontic treatment of primary molars using metronidazole as an intra-canal medicament: a pilot study

AIM

This was to evaluate the clinical and radiographic outcomes of an antibacterial drug (Metronidazole, Nidazol, IE Ulagay Ilac A.S) application as an intra-canal medicament combined with pulpectomy in infected primary molar teeth.

METHODS

The study material consisted of data collected from children treated at the Dental School Dept. of Paediatric Dentistry in Marmara University between 2000 and 2004. Clinical and radiographic data were collected over 2 years from patients who had received a topical application of metronidazole in root canal dressing before a pulpectomy was completed. Clinical success parameters were: no abscess formation, no fistula, no pain and no pathologic mobility at treated teeth with metranidazole dressing. The overall success and failure rates were analysed. Radiographic diagnosis was standardized between investigators and intra and inter-rater reliability assessed. Both investigators read and evaluated all radiographs, after a comparison of results, a consensus was agreed upon for each result.

STATISTICS

All data were entered into an Excel format and SPSS 11.0 P < 0.05 were used for Windows and Chi-square for statistical analyses.

RESULTS

There were 64 molars assessed for clinical and radiographic success. Considering the eruption times, success rate was 75% as determined by the last follow up clinically and radiographically according to predetermined success criteria. In the 64 molars, 4 cases demonstrated loss of the alveolar bone, 3 exhibited varying degrees of root resorptions on radiographic examination and 3 showed clinical pathologic mobility. Fistulae were observed in only 1 case and early loss was detected in 5 cases.

CONCLUSION

These results suggest that main factors responsible for failure may be associated with uncertain mixing proportions of the metronidazole paste and inadequate maxillary restorations. But some modifications in preparing the paste could increase its efficacy.

An agar diffusion study comparing the antimicrobial activity of Nanoseal with some other endodontic sealers

The aim of this study was to evaluate the antimicrobial activity of a new experimental nano-hydroxyapatite epoxy resin-based sealer (Nanoseal) with several other commercially available sealers; AH26, Tubliseal, Sealapex and Roekoseal against Enterococcus faecalis, Pseudomonas aeruginosa, Streptococcus mutans, Streptococcus sobrinus and Escherichia coli for up to 7 days. Agar diffusion was used in this study. Fifty Muller-Hinton agar plates were prepared and divided into five experimental groups (n = 10), for each micro-organism. Another 10 agar plates were used as positive and negative controls. Endodontic sealers were tested against each micro-organism. Inhibition zones produced were recorded. The results of this study showed that all test materials exhibited inhibition zones towards the tested micro-organisms for 7 days except for Roekoseal, which showed no inhibition zones. Nanoseal and AH26 exhibited similar zones of inhibition. Significant difference was found between Nanoseal and the other tested sealers (P < 0.001).

JF. Influence of serum and necrotic soft tissue on the antimicrobial effects of intracanal medicaments

The purpose of this study was to investigate the influence of serum and necrotic soft tissue on the antimicrobial activity of intracanal medicaments. The medicaments tested were: calcium hydroxyde/glycerin paste, calcium hydroxide/chlorhexidine paste, calcium hydroxide/camphorated paramonochlorophenol/glycerin paste, and chlorhexidine/zinc oxide paste. Survival of Enterococcus faecalis and Candida albicans exposed to the medicaments tested in the presence or absence of serum or necrotic tissue was monitored in three in vitro experiments where samples for culturing were taken at different time periods. The overall results demonstrated that the antimicrobial activity of all intracanal medicaments tested was slowed down in the presence of necrotic tissue. Calcium hydroxide pastes in glycerin or chlorhexidine were significantly affected by serum. Of the medicaments tested in this study, the least affected was the calcium hydroxide/camphorated paramonochlorophenol/glycerin paste.

Histomicrobiologic aspects of the root canal system and periapical lesions in dogs' teeth after rotary instrumentation and intracanal dressing with Ca(OH)2 pastes

OBJECTIVE:

The purpose of this study was to evaluate the distribution of microorganisms in the root canal system (RCS) and periapical lesions of dogs' teeth after rotary instrumentation and placement of different calcium hydroxide [Ca(OHy-based intracanal dressings.

MATERIALS AND METHODS:

Chronic periapical lesions were experimentally induced in 80 premolar roots of four dogs. Instrumentation was undertaken using the ProFile rotary system and irrigation with 5.25% sodium hypochlorite. The following Ca(OH)₂-based pastes were applied for 21 days: group 1 - Calen (n=18); group 2 - Calen+CPMC (n=20); group 3 - Ca(OH₂ p.a. + anaesthetic solution (n=16) and group 4 - Ca(OH₂ p.a.+ 2% chlorhexidine digluconate (n=18). Eight root canals without endodontic treatment constituted the control group. Histological sections were obtained and stained with Brown & Brenn staining technique to evaluate the presence of microorganisms in the main root canal, ramifications of the apical delta and secondary canals, apical cementoplasts, dentinal tubules, areas of cemental resorption and periapical lesions. The results were analyzed statistically by the Mann-Whitney U test (p<0.05).

RESULTS:

The control group showed the highest prevalence of microorganisms in all sites evaluated. Gram-positive cocci, bacilli and filaments were the most frequent morphotypes. Similar microbial distribution patterns in the RCS and areas of cementum resorption were observed in all groups (p>0.05). The percentage of RCS sites containing microorganisms in groups 1, 2, 3, 4 and control were: 67.6%, 62.5%, 78.2%, 62.0% and 87.6%, respectively.

CONCLUSION:

In conclusion, the histomicrobiological analysis showed that the rotary instrumentation and the different calcium hydroxide pastes employed did not effectively eliminate the infection from the RCS and periapical lesions. However, several bacteria seen in the histological sections were probably dead or were inactivated by the biomechanical preparation and calcium hydroxide-based intracanal dressing.

Antibacterial activity of propolis-based toothpastes for endodontic treatment

This study evaluated the antibacterial activity of propolis-based toothpastes used as intracanal medication in endodontic treatment. The propolis-based toothpastes were prepared using an extract established in previous studies (identified as A70D and D70D). Calcium hydroxide paste was used as a control. The bacteria employed were Streptococcus mutans (ATCC 25175), Staphylococcus aureus (ATCC 6538), Staphylococcus aureus (ATCC 25923), Kocuria rhizophila (ATCC 9341), Escherichia coli (ATCC 10538), Pseudomonas aeruginosa (ATCC 27853), Enterococcus hirae (ATCC 10541), Streptococcus mutans (ATCC 25175). Five field strains isolated from saliva were used: Staphylococcus spp. (23.1 - coagulase positive), Staphylococcus spp. (23.5 - coagulase negative), Staphylococcus spp. (26.1 - coagulase positive), Staphylococcus spp. (26.5 - coagulase negative) and Staphylococcus epidermidis (6epi). The diffusion-well method on double-layer agar was used in a culture medium of Tryptic Soy Agar. The plates were kept at room temperature for two hours to allow the diffusion of pastes in the culture medium, and then incubated at 35º C for twenty-four hours in aerobiosis and in microaerophilia (S. mutans). After this period, the total diameter of the inhibition halo was measured. The results were analyzed by ANOVA analysis of variance, followed by the Tukey test at p<0.05. The propolis-based toothpastes presented antibacterial activity against 83.3% of the analyzed bacteria. For 66.7% of these bacteria, the propolis-based toothpastes exhibited greater antibacterial activity than calcium hydroxide. The present results allow us to conclude that the experimental pastes A70D and D70D showed good activity against aerobic bacteria, proving more effective than calcium hydroxide.