Biocompatibility of dental materials used in contemporary endodontic therapy: a review. Part 1. Intracanal drugs and substances

Comparative Evaluation of Antifungal Efficacy of 3% Sodium Hypochlorite, 2% Chlorhexidine Gluconate, Ozonated Water, Alum Water, and Normal Saline Solutions against Endodontopathogenic Microorganism, Candida Albicans: A Microbiological In Vitro Study

Aims and objective

To compare and evaluate the antifungal efficacy of 3% sodium hypochlorite (NaOCl), 2% chlorhexidine (CHX) gluconate, 4 mg/mL ozonated water, and 2M alum water against Candida albicans (C. albicans).

Materials and methods

A total of 35 patients were selected from those attending the outpatient department of Pedodontics and Preventive Dentistry at Santosh Dental College and Hospitals, Ghaziabad. Their salivary samples were taken and cultured on a Sabouraud's dextrose agar (SDA) plate. The antifungal efficacy of 3% NaOCl, 2% CHX gluconate, 4 mg/mL concentration of ozonated water, and 2M alum water was assessed against clinical strains of C. albicans with the help of agar well diffusion method. The microbial isolates were inoculated into 10 mL of sterile peptone water and incubated at 37°C for 8 hours. The cultures were swabbed on the surface of sterile Mueller-Hinton agar plates using a sterile cotton swab. Five wells of 6 mm diameter were punched in each Petri dish. Around 100 µL of each test solution was poured into the designated wells. Further, the plates were incubated in an upright position at 37°C for 24 hours. The antifungal activity of the test solutions was determined by measuring the diameter of the inhibition zone in mm produced against the Candida isolates, and means were calculated.

Results

It was observed that all test solutions used in this study were inhibitory against C. albicans but with a variation in the size of inhibitory zones. According to the means of the diameter of inhibitory zones for all test solutions, the 3% NaOCl represented the statistically significant largest average zones of inhibition against C. albicans, followed by 2% CHX when compared with the other two test solutions alum water and ozonated water. Ozonated water produced the smallest mean inhibitory zone.

How to cite this article

Sharma A, Naorem N, Srivastava B, et al. Comparative Evaluation of Antifungal Efficacy of 3% Sodium Hypochlorite, 2% Chlorhexidine Gluconate, Ozonated Water, Alum Water, and Normal Saline Solutions against Endodontopathogenic Microorganism, Candida Albicans: A Microbiological In Vitro Study. Int J Clin Pediatr Dent 2024;17(S-1):S17-S24.

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

AIM

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSION

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

CLINICAL SIGNIFICANCE

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

Research methods assessing sodium hypochlorite cytotoxicity: A scoping review

Sodium hypochlorite (NaOCl) cytotoxicity has been assessed using different methodologies, which has led to arbitrary interpretations. This scoping review aimed to discuss the different methodological protocols for assessing NaOCl cytotoxicity. A literature review performed in the PubMed and Embase databases up to July 2023 identified manuscripts reporting NaOCl cytotoxicity. The dataset identified 546 publications, further screened by 2 reviewers. Ninety studies were identified and mined methodologically to collect information on cell type, cytotoxicity assay, NaOCl dilution solutions, presence of fetal bovine serum (FBS), and NaOCl exposure time. The culture medium used in cytotoxicity assays contains buffering substances that neutralize the pH of NaOCl, thus reducing its cytotoxicity, an approach that may lead to bias when solutions with different pH are compared. For short exposure periods, as in simulations to evaluate the contact between irrigant and periapical tissue cells during chemo-mechanical preparation, NaOCl dilution should be performed with saline, which does not buffer the irrigant. For long exposure periods, as in simulations of irrigant extrusions, NaOCl should be diluted in the culture medium, to reproduce the expected buffering effect occurring in extrusions. The presence of FBS in culture medium can decrease NaOCl toxicity. There is no standardization of NaOCl cytotoxicity methodologies. This poses the risk of arriving at incorrect results and, therefore, pertinent tests must be refined.

Combined effect of electrical energy and graphene oxide on Enterococcus faecalis biofilms

This study aimed to investigate the effects of electrical energy and its synergistic activity with graphene oxide (GO) in Enterococcus faecalis (E. faecalis) biofilms. The viability of E. faecalis biofilms was analyzed by colony-forming units, crystal violet staining, and confocal laser scanning microscopy. The morphologies of the biofilms and the bacterial organelles were observed by scanning electron microscopy and transmission emission microscopy (TEM), respectively. Application of electrical energy combined with 0.2% sodium hypochlorite (NaOCl) on E. faecalis in biofilms significantly decreased the bacterial viability and biofilm biomass compared to the 0.2% NaOCl-only-treated group. Furthermore, additional application of GO showed similar antibacterial effects to 0.5% NaOCl. Notably, TEM observation revealed that the bacteria treated with electric energy and GO showed damaged cell membranes. The results suggest that combination of electrical energy and GO enhances antibacterial activity of NaOCl and has the potential to be applied to root canal irrigation protocols.

The Potential Uses of Baobab Tree's Medicinal Effects in Dentistry: A Literature Review

Adansonia digitata (Baobab) tree is an African tree with a long history in traditional medicine. The local inhabitants of Africa have been using the different tree components to treat medical diseases, such as fever, diarrhea, malaria, cough, dysentery, and microbial infections. Recently, the tree gained the attention of scientists due to its medical and pharmaceutical properties and nutritional values, which generated a myriad number of investigations regarding its phytochemical and macro- and micronutrient contents. The fruit pulp is especially rich in vitamin C, pectin, fibers, and minerals such as calcium, magnesium, potassium, phosphorus, zinc, iron, and copper. Additionally, the leaves contain high levels of calcium, while the seeds are considered a good source of protein and fat. Altogether, they contain a variety of polyphenols, fatty acids, and amino acids. The tree extracts possess potent antioxidant, cell-protective, and anti-inflammatory activities. However, no information was found in the literature about the use of Baobab tree products in the dental field. The aim of this review is to discuss the well-documented medical effects and chemical and mineral components of the different Baobab tree parts from a dental point of view to open more areas of research concerning its potential applications in the dental field. Antioxidants and vitamin C are known to help in maintaining healthy periodontal and gingival tissues. They also help in wound healing and alveolar bone integrity. Moreover, phytochemicals and phenolic compounds have been utilized in controlling dental plaque and manufacturing intracanal medications as they manifest antimicrobial and anti-inflammatory activities. Furthermore, calcium and phosphorus incorporation in dental biomaterials is commonly used in vital pulp therapy and repairing bone defects. After reviewing the reported medicinal and pharmaceutical activities of the Baobab tree, it can be inferred that the tree extracts possess potential uses in the dental field, which requires further investigation for validation.

Cytotoxicity and genotoxicity of Bio-C Repair, Endosequence BC Root Repair, MTA Angelus and MTA Repair HP

The aim was to evaluate in vitro cytotoxicity and genotoxicity of Bio-C Repair (BCR), compared to Endosequence BC Root Repair (ERRM), MTA Angelus (MTA-Ang), and MTA Repair HP (MTA-HP). MC3T3 osteoblastic cells were exposed to extracts of the repairing bioceramic cements. After 1, 3, and 7 days, cytotoxicity and genotoxicity were evaluated by MTT and Micronucleus tests, respectively. Cells not exposed to biomaterials were used as a negative control. Data were compared using ANOVA two-way, followed by the Tukey Test (α=5%). MTA-Ang and MTA-HP showed no difference in relation to control regarding cytotoxicity in any experimental times. BCR and ERRM reduced cell viability after 3 and 7 days (p<0.05); however, the reduction caused by BCR was less than that caused by ERRM. Considering the micronucleus formation, all biomaterials caused an increase after 3 and 7 days (p<0.05), being greater for the BCR and ERRM groups. It can be concluded that BCR is non-cytotoxic in osteoblastic cells, as well as MTA-Ang e MTA Repair HP. BCR and ERRM showed greater genotoxicity than others tested biomaterials.

Antimicrobial efficacy of sodium hypochlorite, saline, and Er, Cr:YSGG laser-assisted disinfection in root canal treatment of primary molars: An in vivo study

Aim

The aim of the study was to compare the antimicrobial efficacy of sodium hypochlorite (NaOCl), Saline, and Er, Cr:YSGG laser-assisted disinfection through microbiological analysis in root canal treatment of primary molars.

Materials and Methods

Forty-five primary teeth were selected for this study as per the inclusion and exclusion criteria in the age group of 4-8 years and then randomly allocated to Three Groups A, B, and C. In Group A, during root canal treatment, irrigation was done using NaOCl, in Group B, laser-assisted disinfection was done using Er, Cr:YSGG laser, and in Group C, saline was used as an irrigating agent. This was followed by obtaining pre- and postirrigation samples from the canals for microbiological investigation in all the groups. Data analysis was performed using Statistical Package for the Social Science-21 (SPSS-21).

Results

NaOCl was more effective against aerobic bacteria while Er, Cr:YSGG laser was more effective against anaerobic bacteria when used for disinfection in root canal treatment. There was a significant difference among the three groups (P > 0.05).

Conclusion

The study showed that NaOCl and Er, Cr:YSGG laser have antimicrobial effects when used for disinfection in root canal treatment of primary teeth. Moreover, the study also shows that Er, Cr:YSGG laser may be used as a valuable tool for laser-assisted disinfection in root canal treatment of primary teeth.

Determining the potential use of biosurfactants in preventing endodontic infections

Microbial biofilms play a dominant role in the failure of endodontic therapies. Bacterial adhesion is the first step in the establishment of biofilms, activating the host immune response leading to tissue damage. Biosurfactants are microbe-derived tensioactive molecules with latent anti-adhesive and anti-microbial activity. This study reports the extraction and characterization of a biosurfactant from Lactobacillus (L.) plantarum (Lp-BS) and investigates its anti-microbial and anti-adhesive properties compared to rhamnolipid, a commercially available biosurfactant. Lp-BS, extracted from L. plantarum during the growth phase, was characterized as a glycoprotein, able to reduce surface tension and emulsify non-polar liquids. Proteomic analysis of Lp-BS identified three bacterial adhesin-like proteins, suggesting roles in hindering bacterial adhesion. Lp-BS did not show significant anti-microbial activity against endodontic pathogens from the Streptococcus (Strep.) anginosus group or Enterococcus (Ent.) faecalis at 50 mg/ml. However, anti-adhesive activity on abiotic surfaces was observed against both Strep. anginosus and Strep. intermedius. Rhamnolipid exhibited strong anti-microbial activity, with minimum inhibitory concentrations of 0.097 mg/ml against Strep. anginosus, and 0.048 mg/ml against Strep. constellatus and Strep. intermedius, in addition to a marked anti-adhesive activity. These findings offer preliminary evidence for the potential application of biosurfactants as an anti-microbial and/or anti-adhesive pharmacotherapy in endodontics.

Evaluation of the diffusion of triamcinolone and demeclocycline through the dentinal tubules and apical foramen: A mass spectrometry study

Aim:

The aim of this study was to investigate the diffusion of triamcinolone and demeclocycline from an endodontic paste when used unmodified, versus when combined in equal parts with a calcium hydroxide paste, in terms of diffusion through the dentinal tubules versus through the apical foramen.

Methodology:

Medicaments were placed in endodontically prepared roots that were kept in vials of Milli-Q water. The five experimental groups in the study were (1) control – no medicament, (2) medicament containing triamcinolone and demeclocycline (T&D) and occluded apex, (3) T&D paste and patent apex, (4) T&D + calcium hydroxide (Ca(OH)₂) occluded apex, and (5) T&D + Ca(OH)₂ and patent apex. The triamcinolone and demeclocycline concentrations were measured with solid-phase extraction and ultra-high performance liquid chromatography–mass spectrometry, after 1, 3, 8, and 24 h, and after 1 week.

Results:

Most of the triamcinolone and demeclocycline diffused through the apical foramen, with sparse diffusion through the dentinal tubules. The T&D paste mixed with Ca(OH)₂ in equal amounts showed greater than the expected 50% reduction in the diffusion of triamcinolone and demeclocycline from mass dilution alone (89% and 80%, respectively).

Conclusions:

These results stress the importance of maintaining apical patency, for allowing diffusion of active components of the drugs to target tissues in the periapical environment.

A small molecule II-6s inhibits Enterococcus faecalis biofilms

Background

Limitations of current intracanal irrigants such as sodium hypochlorite (NaOCl) and chlorhexidine (CHX) necessitate the development of novel antimicrobial agents to control endodontic infection.

Aim

This study investigated the antimicrobial activities of a small molecule II-6s against Enterococcus faecalis associated with endodontic diseases.

Methods

The susceptibility of E. faecalis to II-6s was evaluated by the microdilution method and time-kill assay. Microbial resistance was assessed by repeated exposure of E. faecalis to II-6s. Cytotoxicity of II-6s was evaluated by CCK-8 assay. Virulence gene expression of the II-6s-treated E. faecalis cells was measured by RT-qPCR. Bacterial reductions in the dentinal tubules were further assessed by confocal laser scanning microscopy.

Results

II-6s exhibited potent antimicrobial activity against E. faecalis and down-regulated virulence-associated genes in E. faecalis. II-6s induced no drug resistance in E. faecalis with lower cytotoxicity as compared to NaOCl and CHX. More importantly, 0.003125% II-6s exhibited significant bactericidal effect against E. faecalis residing in the dentinal tubules, which was comparable to 5.25% NaOCl and 2% CHX.

Conclusions

II-6s has excellent antimicrobial activity, moderate cytotoxicity and induces no drug resistance, and thus is a promising agent for the treatment of endodontic infection.

The Effect of Photodynamic Therapy on the Smear Layer Removal: a Scanning Electron Microscopic Study

Statement of the Problem

The efficacy of photodynamic therapy (PDT) in smear layer removal compared to the currently accepted protocol is not well established.

Purpose

This study aims to evaluate the effect of PDT on smear layer removal from human root canal compared to combined use of irrigation solutions including sodium hypochlorite (NaOCl) and ethylene diamine tetra acetic acid (EDTA) by scanning electron microscopy (SEM).

Materials and Method

In this in vitro study, straight roots from 48 extracted human maxillary incisors and canines were selected and decoronated. Instrumentation was completed with RaCe rotary system and normal saline irrigation between files. Then roots were randomly divided into 3 groups (n=16). Group 1 was the control group to confirm smear layer formation. In the group 2, the canals were irrigated with 2ml of 2.5% NaOCl solution for 10 minutes and 2ml of 17% EDTA solution for 1 minute. In the group 3, PDT with methylene blue and diode laser (625nm, 150mW, for 5minutes) was the final procedure for smear layer removal. All the specimens were sectioned into two halves, gold coated, and analyzed under SEM. The smear layer in the coronal, middle, and apical thirds, were evaluated and scored by two examiners independently. Statistical analysis was done using Chi-square test.

Results

It was observed that the NaOCl+EDTA removed the smear layer significantly better than PDT in the coronal and apical thirds (p< 0.05) whereas PDT was unable to remove the smear layer in none of the root areas. At the apical thirds, there was no significant difference between NaOCl+EDTA and PDT (p< 0.05). Both procedures were unable to remove smear layer from radicular dentine of this area.

Conclusion

According to the results of this in vitro study, the use of PDT alone is not recommended to remove smear layer. The combined application of NaOCl and EDTA is ineffective in removing smear layer of apical third, despite its efficacy on the coronal and middle regions.

Does MTA provide a more favourable histological response than other materials in the repair of furcal perforations? A systematic review

BACKGROUND

There is no consensus on which furcal perforation repair material induces a more favourable histological response. This systematic review of laboratory studies provides an overview of the studies comparing repair materials in animal models.

OBJECTIVES

To evaluate whether mineral trioxide aggregate (MTA) yields a more favourable histological response than other materials when used to repair furcal perforations in animal experimental models.

METHODS

This review followed the PRISMA checklist. The studies included various materials used to repair furcal perforations and compared the histological responses with MTA. An electronic search was conducted in EMBASE, PubMed, Scopus and Web of Science up to 2 September 2020, with no language or publication date restrictions. Studies whose full text was unavailable were excluded. The ARRIVE and SYRCLE tools were used to assess the methodological quality and risk of bias (RoB) of the studies.

RESULTS

The studies included in the qualitative synthesis were conducted in rat (n = 3) and dog (n = 17) models. They were classified as having a low quality, high methodological heterogeneity and high RoB. MTA and Biodentine, the materials most often compared, reduced the inflammatory reaction to mild over time. In addition, a mineralized tissue was formed in all studies. The response yielded by MTA was better than or equivalent to that of the other tested materials.

DISCUSSION

This review confirmed that MTA is the reference standard material for furcal perforation repair. However, research using animal models has inherent limitations, and the substantial methodological heterogeneity across the studies included should be considered. Therefore, the knowledge generated by this systematic review should be translated into clinical practice cautiously.

CONCLUSIONS

Features described in the report and quality assessment guidelines, such as PRIASE, ARRIVE and SYRCLE, should guide researchers. Despite the high RoB and the low methodological quality of the studies included, findings indicated that MTA yields a more favourable histological response than other materials in the repair of furcal perforations.

REGISTRATION

PROSPERO (CRD42020181297).

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.

Comparison between immediate and delayed post space preparations: a systematic review and meta-analysis

OBJECTIVES

This systematic review and meta-analysis compared the effects of immediate and delayed post space preparation on apical sealing.

MATERIALS AND METHOD

Two independent authors conducted a systematic search (PubMed/Medline, Cochrane Library, and other databases, until February 2020) and a risk of bias evaluation. Only in vitro studies that compared the effects of immediate and delayed post space preparations on apical filling and adhesion of the post were eligible.

RESULT

Of the 742 articles retrieved, 32 were included. Most of the studies used single-rooted human teeth and rotary files for root canal preparation, a single-cone technique for the filling protocol, and rotary instruments for post space preparation. Various delayed preparation times were evaluated: 8-72 h, 5-30 days (mainly 7 days), and 4 months. In nine studies, the delayed groups showed more apical leakage, while four studies reported more leakage in the immediate groups; ten studies found no significant difference. One study found more bacterial penetration in the delayed group, whereas three studies showed no significant difference. One study reported more voids in the delayed group, while another found no such difference. Three studies showed better post-bond strength in the delayed group, one in the immediate group, whereas three found no significant difference in post-bond strength. Three studies employing varied sealers for root canal fillings were considered for meta-analysis. Two subgroup analyses were also performed (one concerning the use of resin-based sealers (AH Plus), another for zinc oxide-eugenol-based sealers). The results of the meta-analysis showed that a delayed post space preparation led to a significantly higher apical leakage than an immediate preparation (mean difference = 0.41 mm, confidence interval = 0.24-0.59, p < 0.001).

CONCLUSION

Delayed post space preparation seems to negatively influence apical sealing; however, further studies are needed to determine the influence of the timing of post space preparation on the other parameters.

CLINICAL RELEVANCE

Immediate post space preparation may be the safest clinical choice to prevent apical leakage.

In vivo Biocompatibility and Bioactivity of Calcium Silicate-Based Bioceramics in Endodontics

Endodontic therapy aims to preserve or repair the activity and function of pulp and periapical tissues. Due to their excellent biological features, a substantial number of calcium silicate-based bioceramics have been introduced into endodontics and simultaneously increased the success rate of endodontic treatment. The present manuscript describes the in vivo biocompatibility and bioactivity of four types of calcium silicate-based bioceramics in endodontics.

Near-infrared NIR irradiation and sodium hypochlorite: An efficacious association to counteract the Enterococcus faecalis biofilm in endodontic infections

New strategies are necessary for the prevention of endodontic infections caused by Enterococcus faecalis, a common resistant pathogen and biofilm producer. Aim of the present study was to compare the effects of Near-Infrared (NIR) Light-Emitting Diode (LED) irradiation and different concentrations of sodium hypochlorite (NaOCl) alone or combined to each other on the E. faecalis biofilm, on artificial and human dentin surfaces. E. faecalis ATCC 29212 preformed biofilms, on polystyrene wells and on dentin discs, were treated with 880 nm NIR irradiation and NaOCl at 4%, 2.5%, 1% and 0.5% alone and combined to each other (NIR irradiation plus NaOCl 1% or 0.5%) at 5 and 10 min. Treated biofilms were compared to the controls for (i) biofilm biomass evaluation, (ii) CFU count for the quantification of cultivable cells and (iii) cells viability. All the detected experimental conditions displayed a significant reduction of biofilm biomass (p < 0.001) and CFUs/mL (p < 0.01) in respect to the controls on both tested surfaces. The effects on the E. faecalis biomass, colony count and cell viability were not time-dependent except for NaOCl 2.5% and 1% in the biofilm biomass reductions on human dentin discs. NIR-LED irradiation alone showed a reduction of E. faecalis aggregates without interfering with cell viability whereas NaOCl alone expressed a killing effect in a concentration dependent way. The combination of NIR-LED irradiation with NaOCl 1% and 0.5% displayed a double effect of cluster disaggregation and cell killing. In particular, NIR-LED irradiation combined with NaOCl 0.5% displayed an anti-biofilm activity major than those expressed by NaOCl 0.5% alone (p = 0.001) with a reduction of biomass 93% vs 71% and 97% vs 25% after 10 min, on polystyrene wells and human dentin discs, respectively. The innovative use of NIR-LED irradiation combined at short times with low concentration of NaOCl (1% and 0.5%) is capable to reach a significant effect on E. faecalis biofilm, especially on human dentin discs.

Evaluation of various irrigation activation systems to eliminate bacteria from the root canal system: A randomized controlled single blinded trial

OBJECTIVE

To evaluate the effect of NaOCl irrigant activation using passive ultrasonic activation, F-files, XP-endo Finisher files and or needle irrigation alone on the reduction of intracanal bacteria from root canals in teeth undergoing root canal treatment.

METHODS

Eighty patients with asymptomatic apical periodontitis were randomly divided into four groups. Access cavities were prepared and pre-treatment samples were taken (S1). Canals were then prepared and post-instrumentation samples (S2) taken. NaOCl was then activated with the various irrigant activation systems and post-irrigation samples (S3) taken. The samples were processed and colony forming units (CFUs) of bacteria were determined. The reduction in CFUs among the experimental groups were analysed using the Kruskal Wallis test and pairwise comparisons with the Mann-Whitney test. The Friedman test was used to compare the differences in the reduction of CFUs within the groups.

RESULTS

Overall, for all groups there was a significant reduction in the CFUs from S1 to S2 (P < 0.05) and from S2 to S3 (P < 0.05). Both XP-endo Finisher and passive ultrasonic activation techniques were associated with the greatest reduction in CFUs with no significant difference between them (P = 0.24). However, both were associated with significantly lower CFUs when compared to F-file activation and needle irrigation (P < 0.05). F-file activation reduced the CFUs significantly more compared to needle irrigation (P = 0.04).

CONCLUSIONS

XP-endo Finisher file activation and passive ultrasonic activation were equivalent in terms of reduction in CFUs. F-file activation did not reduce the CFUs to the same extent as the XP-endo Finisher file and ultrasonic activation but reduced the CFUs more than needle irrigation.

CLINICAL SIGNIFICANCE

The present study highlights the effect of new XP-endo Finisher file and passive ultrasonic activation in reducing the bacterial load from the root canal system which is important for the success of root canal treatment.

Systemic and Local Biocompatibility Assessment of Graphene Composite Dental Materials in Experimental Mandibular Bone Defect

The main objective of this research is to demonstrate the biocompatibility of two experimental graphene dental materials by in vitro and in vivo tests for applications in dentistry. The novel graphene dental materials, including one restorative composite and one dental cement, were subjected to cytotoxicity and implantation tests by using a rat model of a non-critical mandibular defect. In vitro cytotoxicity induced by materials on human dental follicle stem cells (restorative composite) and dysplastic oral keratinocytes (dental cement) was investigated at 37 °C for 24 h. After in vivo implantation, at 7 weeks, bone samples were harvested and subjected to histological investigations. The plasma biochemistry, oxidative stress, and sub-chronic organ toxicity analysis were also performed. The resulting cytotoxicity tests confirm that the materials had no toxic effects against dental cells after 24 h. Following graphene dental materials implantation, the animals did not present any symptoms of acute toxicity or local inflammation. No alterations were detected in relative organ weights and in correlation with hepatic and renal histological findings. The materials' lack of systemic organ toxicity was confirmed. The outcomes of our study provided further evidence on the graphene dental materials' ability for bone regeneration and biocompatibility.

Efficacy of the photon-initiated photoacoustic streaming combined with different solutions on Enterococcus faecalis in the root canals

This study aimed to evaluate the efficacy of different irrigation solutions used in photon-initiated photoacoustic streaming (PIPS) or conventional needle irrigation (CNI) for eradication of Enterococcus faecalis from artificial root canals. Altogether, 240 artificial root canal samples were included. The models were split and incubated for 2 days to allow formation of E. faecalis biofilm. The models were randomly divided into two groups (n = 120): CNI and laser-activated irrigation (LAI). Each group was divided into six subgroups according to different irrigation solutions: distilled water, 1% sodium hypochlorite (NaOCl), 2% NaOCl, 5.25% NaOCl, MTAD, and chlorhexidine, respectively. After irrigation, half of the samples (n = 10) were assessed immediately, and the other half of the samples (n = 10) were incubated for 6 hr. Bacterial suspensions were obtained from all samples before and after irrigation, and after incubation, and were quantified adenosine 5'-triphosphate (ATP) assay kit. The biofilms were examined using fluorescent microscopy and analyzed by Image Pro Plus software. Significant reduction of ATP, average fluorescence density after irrigation, and growth after incubation was obtained in LAI group than in CNI group (p < .05). LAI can improve bacteriostasis effect of 2% NaOCl (p < .05). PIPS improved the antibacterial effect of the 2% NaOCl used in root canal therapy.

Comparative evaluation of three obturation systems in primary molars - A randomized clinical trial

OBJECTIVES

The objective of this study is to evaluate and compare the radiographic efficacy of the quality of obturation and to assess the number of voids and the obturation time in primary teeth using Pastinject™, disposable needle, and capillary tips.

MATERIALS AND METHODS

A total of 34 teeth with 103 canals were randomly divided into three groups using chit method, based on used application: Group 1: Pastinject™ (Micro-Mega, Besancon, France); Group 2: Disposable needle (23G short needle BD Discardit™, Becton Dickinson India Pvt. Ltd.), and Group 3: Capillary tips (Meta Biomed^© Co. Ltd., China). All the groups were named based on obturation systems used. To compare the quality of obturation, the Chi-square test was used; to assess the number of voids, Kruskal-Wallis ANOVA test was used; and to evaluate the obturation time, post hoc Scheffe one-way ANOVA test was used. All P values having <0.05 were considered as statistical significant (P < 0.05). Kappa statistics were performed to check interexaminer reliability. Descriptive statistics were used for evaluation using SPSS (version. 21).

RESULTS

Capillary tips resulted in better optimal filled canals and less obturation time, compared to disposable needle and Pastinject (P < 0.001). There was no significant difference evident among three groups in relation to voids (P = 0.111).

CONCLUSION

Capillary tip technique proved to be the most effective, yielding a higher number of optimally filled canals and minimal voids, combined with easier placement of the material into the canals when compared to Pastinject and disposable needle obturation.

Cytotoxicity evaluation of fungal-derived silver nanoparticles on human gingival fibroblast cell line: An in vitro study

Background:

Biosynthesized silver nanoparticles (AgNPs) have been proposed as effective antimicrobial agents against endo–perio pathogens. Determination of cytotoxicity is important for effective clinical use.

Aim:

The aim is to determine the cytotoxicity of fungal-derived AgNPs on human gingival fibroblast (HGF) cell line using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay.

Materials and Methods:

HGF cell cultures were trypsinized and adjusted to 5 × 10³ cells/ml and 100-μl cell suspension (50,000 cells/well) and were added to 96-well plate. After 24 h, 100 μl of AgNPs (8–512-μg/ml concentrations) was added and incubated at 37°C for 24 h in 5% CO₂ atmosphere. Controls were used without AgNPs. MTT (1 mg/ml) was added and incubated for 4 h at 37°C in 5% CO₂ atmosphere. Microscopic examination was done, and absorbance was measured using a microplate reader at a wavelength of 540 nm. Percentage growth inhibition was calculated, and the concentration of AgNPs needed to inhibit cell growth by 50% (CTC₅₀) was generated.

Results:

CTC₅₀ was found at a concentration of 260 μg/ml. AgNPs exerted less cytotoxicity against HGF cell line and increased with increase in the concentration of AgNPs.

Conclusion:

Fungal-derived AgNPs are safe to healthy cells at a concentration <260 μg/ml. Therefore, they can be effectively used for the treatment of endo–perio lesions.

Molecular insight to size and dose-dependent cellular toxicity exhibited by a green synthesized bioceramic nanohybrid with macrophages for dental applications

Improvising bioceramics for enhancing their biocompatibility and physical properties has been a focus area for the dental industry. To further explore this area, this study reports a novel green synthesis and molecular in vitro biocompatibility of calcium aluminosilicate-chitosan nanohybrid (CAS-CH). The nanohybrids were synthesized by using a high energy ball milling (HEBM) technique and then characterized for their physiochemical properties using standard techniques including scanning electron microscopy (SEM) and dynamic light scattering (DLS). In vitro cytotoxicity evaluation of a synthesized nanohybrid was made with a RAW264.7 cell line using cell viability assays, such as, MTT, cellular morphology analysis, induction of oxidative stress, and apoptosis. CAS-CH nanohybrids were synthesized at three milling time points: 1H, 2H, and 3H. With increasing milling time, we found a reduction in sizes of particles and increased zeta potential. Viability of cells was found to be decreased with an increase in concentration. Moreover, toxic effects like ROS generation and apoptosis were reduced with increasing milling time. Computational and experimental analysis elucidated the mechanism of toxicity as a consequence of influential functionality of Sod1 and p53 proteins due to interaction and internalization of the nanohybrids with amino acid residues via hydrogen bonds and hydrophobic interactions. The detailed study depicted a novel way of synthesizing biocompatible bioceramic nanohybrids with a mechanistic insight of its cytotoxicity profile.

Effect of Irrigation Time of Antiseptic Solutions on Bone Cell Viability and Growth Factor Release

Antiseptic solutions are commonly utilized to treat local infection in the oral and maxillofacial region. However, surrounding vital bone is also exposed to antiseptic agents during irrigation and may have a potential negative impact on bone survival. The aim of the present study was therefore to investigate the effect of rinsing time with various antiseptic solutions on bone cell viability, as well as their subsequent release of growth factors important for bone regeneration. The bone samples collected from porcine mandible were rinsed in the following commonly utilized antiseptic solutions; povidone-iodine (0.5%), chlorhexidine digluconate (CHX, 0.2%), hydrogen peroxide (1%), and sodium hypochlorite (0.25%) for 1, 5, 10, 20, 30, or 60 minutes and assessed for cell viability and release of growth factors including vascular endothelial growth factor, transforming growth factor beta 1, bone morphogenetic protein 2, receptor activator of nuclear factor kappa-B ligand, and interleukin-1 beta by enzyme-linked immunosorbent assay. It was found in all the tested groups that the long exposure of any of the tested antiseptic solutions drastically promoted higher cell death. Sodium hypochlorite demonstrated the significantly highest cell death and at all time points. Interestingly, bone cell viability was highest in the CHX group post short-term rinsing of 1, 5, or 10 minutes when compared with the other 4 tested groups. A similar trend was also observed in subsequent growth factor release. The present study demonstrated that of the 4 tested antiseptic solutions, short-term CHX rinsing (ideally within 1 minute) favored bone cell viability and growth factor release. Clinical protocols should be adapted accordingly.

Factors affecting the periapical healing process of endodontically treated teeth

Tissue repair is an essential process that reestablishes tissue integrity and regular function. Nevertheless, different therapeutic factors and clinical conditions may interfere in this process of periapical healing. This review aims to discuss the important therapeutic factors associated with the clinical protocol used during root canal treatment and to highlight the systemic conditions associated with the periapical healing process of endodontically treated teeth. The antibacterial strategies indicated in the conventional treatment of an inflamed and infected pulp and the modulation of the host's immune response may assist in tissue repair, if wound healing has been hindered by infection. Systemic conditions, such as diabetes mellitus and hypertension, can also inhibit wound healing. The success of root canal treatment is affected by the correct choice of clinical protocol. These factors are dependent on the sanitization process (instrumentation, irrigant solution, irrigating strategies, and intracanal dressing), the apical limit of the root canal preparation and obturation, and the quality of the sealer. The challenges affecting the healing process of endodontically treated teeth include control of the inflammation of pulp or infectious processes and simultaneous neutralization of unpredictable provocations to the periapical tissue. Along with these factors, one must understand the local and general clinical conditions (systemic health of the patient) that affect the outcome of root canal treatment prediction.

Initial cytotoxicity assays of media for sulfate-reducing bacteria: An endodontic biopharmaceutical product under development

This study assessed the cell viability of the inoculation vehicle of BACCOR (a combination of sulfate-reducing bacteria plus a culture media for bacteria), a biopharmaceutical product under development for dental use as aid in fractured endodontic file removal from the root canal. Different culture media for bacteria were evaluated: modified Postgate E (MCP-E mod), Modified Postgate E without Agar-agar (MCP-E w/Ag), Postgate C with Agar-agar (MCP-C Ag) and Postgate C without Agar-agar (MCP-C w/Ag). Cytotoxicity was quantified by the MTT test, exposing L929 and Vero cell lines to the vehicles over 24 h. The exposure of L929 cell line to MCP-E w/Ag resulted in biocompatibility (52% cell viability), while the exposure of the Vero kidney line revealed only MCP-E mod as cytotoxic. When diluted, all the vehicles showed biocompatibility with both cell lines. MCP-E w/Ag was the vehicle chosen for BACCOR, because of its biocompatibility with the cells used.

Influência da solução irrigadora na formação de defeitos dentinários após preparo com Sistema Reciproc®

Resumo Introdução Diferentes concentrações de hipoclorito de sódio (NaOCl) estão disponíveis para serem utilizadas durante o preparo biomecânico dos canais radiculares pelos instrumentos reciprocantes. Devido à rapidez com que o canal é instrumentado nessa nova cinemática reciprocante, concentrações mais elevadas de NaOCl são recomendadas. Assim, torna-se oportuna uma investigação para avaliar se a solução irrigadora NaOCl potencializa a possibilidade de formação de defeitos dentinários provocados pelo sistema Reciproc. Objetivo Analisar a influência da solução irrigadora hipoclorito de sódio na formação de defeitos dentinários provocados pelo sistema de instrumentação Reciproc®. Material e método Foram utilizados 60 primeiros pré-molares superiores extraídos, sendo estes distribuídos em dois grupos: (G1) NaOCl 5,25% (n=30) e (G2-controle) água destilada (n=30), nos quais somente o conduto vestibular foi instrumentado com o Sistema Reciproc® e irrigado com as soluções citadas. Todas as coroas dos dentes foram cortadas perpendicularmente ao seu longo eixo e as raízes foram incluídas em alvéolo e ligamento periodontal simulados. Os condutos palatinos não foram instrumentados nem irrigados, pois estes serviram como controle para o próprio espécime. Ao término da instrumentação, as raízes foram seccionadas em 2, 4, 6 e 8 mm a partir do forame apical, e levadas ao microscópio estereoscópico para se avaliar e registrar a formação de defeitos dentinários. Resultado Foram encontrados defeitos dentinários no Grupo controle (G2) e no grupo hipoclorito de sódio 5,25% (G1), porém não houve diferença estatisticamente significante entre esses grupos (p>0,05). Conclusão O hipoclorito de sódio não desencadeou alterações de defeitos dentinários quando utilizado em associação com a instrumentação pelo Sistema Reciproc®.

Biocompatibility of a calcium hydroxide-propolis experimental paste in rat subcutaneous tissue

Intracanal medications are fundamental for disinfection of the root canal system and participate in periapical repair, so their biocompatibility is of utmost importance to avoid tissue damage. This study evaluated the biocompatibility of a experimental paste of calcium hydroxide and propolis in the subcutaneous tissue of rats. The study was conducted on 15 male Wistar rats. Two incisions were made on the dorsal region of each animal for introduction of 4 tubes: one tube was empty; one contained zinc oxide-eugenol cement, and the two other tubes were filled with experimental paste. After 7, 14 and 30 days, the animals were euthanized and the specimens were subjected to histotechnical preparation. The hematoxylin and eosin-stained histological sections were analyzed by light microscopy. Scores were established according to the inflammatory process and statistically compared by the Tukey test (α = 5%). The analysis of histological sections showed non-significant or mild inflammatory reaction in the connective tissue in contact with the empty tubes in all study periods while the contact of subcutaneous tissue with zinc oxide-eugenol elicited moderate or severe inflammation similarly without significant difference among the study periods. The connective tissue was moderately inflamed at 7 days when contacting the experimental paste, but the inflammatory process was non-significant or mild at 14 and 30 days. The experimental paste was biocompatible with the tissues after 14 days of subcutaneous implantation.

Assessment of the biocompatibility of mineral trioxide aggregate, bioaggregate, and biodentine in the subcutaneous tissue of rats

OBJECTIVE

The objective of this study was to evaluate the tissue inflammation caused by three endodontic repair materials.

MATERIALS AND METHODS

The materials included micro mega-mineral trioxide aggregate (MM-MTA), bioaggregate (BA), and biodentine (BD), which were implanted into the subcutaneous tissue of rats. The tissue samples for histological examination were prepared. The infiltration of lymphocytes and macrophages into the tissue was examined to assess the inflammatory response.

RESULTS

Lymphocyte infiltration: A significant increase was detected in the MM-MTA and BA groups on the 7th and 14th days as compared with the control (7th day P=0.0001, 14th day P=0.0176). There was no difference between the groups on the 45th day (P=0.1730). Lymphocyte infiltration had decreased over time in all groups. Macrophage infiltration: There was a significant increase by the 7th day in the test groups as compared to the control group (P=0.007). However, there was no difference between the experimental groups on the 14th (P=0.2708) and 45th (P=0.1291) days.

CONCLUSION

While MM-MTA and BA showed a similar biocompatibility, BD was more biocompatible than MM-MTA and BA in the 1 st week of the experiment. However, there was no difference between the materials at the end of the 45th day. MM-MTA, BA, and BD can be considered suitable endodontic repair materials.

Human Pulp Response to Direct Pulp Capping and Miniature Pulpotomy with MTA after Application of Topical Dexamethasone: A Randomized Clinical Trial

Introduction:

The aim of this randomized clinical trial was to compare the histologic pulp tissue response to one-step direct pulp capping (DPC) and miniature pulpotomy (MP) with mineral trioxide aggregate (MTA) after application of dexamethasone in healthy human premolars.

Methods and Materials:

Forty intact premolars from 10 orthodontic patients, were randomly chosen for DPC (n=20) or MP (n=20). In 10 teeth from each group, after exposure of the buccal pulp horn, topical dexamethasone was applied over the pulp. In all teeth the exposed/miniaturely resected pulp tissue was covered with MTA and cavities were restored with glass ionomer. Teeth vitality was evaluated during the next 7, 21, 42, and 60 days. Signs and/or symptoms of irreversible pulpitis or pulp necrosis were considered as failure. According to the orthodontic schedule, after 60 days the teeth were extracted and submitted for histological examination. The Kruskal-Wallis and Fisher’s exact tests were used for statistical analysis of the data (P=0.05).

Results:

Although dexamethasone specimens showed less inflammation, calcified bridge, pulpal blood vasculature, collagen fibers and granulation tissue formation were not significantly different between the groups (P>0.05).

Conclusion:

Topical dexamethasone did not hindered pulp healing but reduced the amount of underlying pulpal tissue inflammation after DPC and MP in healthy human premolars.

Histological analysis of the biocompatibility of calcium hydroxide associated with a new vehicle

BACKGROUND

Several substances have been researched to act as vehicles associated with calcium hydroxide. The specific type of vehicle is directly related to the effectiveness of the ionic dissociation, antimicrobial action, and biocompatibility of this medication.

AIM

To make a histological evaluation of the biocompatibility of calcium hydroxide associated with a new vehicle (triethanolamine), compared with polyethylene glycol, saline solution, and olive oil.

MATERIALS AND METHODS

Fifty mice of guinea pig species were randomly divided into five groups (n = 10) according to each vehicle used--Group 1: calcium hydroxide, Group 2: triethanolamine, Group 3: polyethylene glycol, Group 4: saline solution, and Group 5: olive oil--and further divided into subgroups according to the two analysis periods--(a) 30 and (b) 90 days. Teflon carriers filled with the evaluated substances were placed in standardized bone cavities in the anterior mandible region. The animals were euthanized to perform a histological analysis after the time periods analyzed.

RESULTS

In 30 days, specimens from Groups 1, 3, and 5 showed a very pronounced inflammatory response. Specimens from Group 2 showed an inflammatory reaction ranging from mild to severe, with rapid resorption of the material and progressive advancement of osteoid tissue into the teflon carriers. Specimens from Group 4 showed a moderate inflammatory reaction. In 90 days, specimens from Group 1 showed a very pronounced fibrous replacement. In regard to Group 2 specimens, the tested material was solubilized and replaced by newly formed bone tissue. For Groups 3 and 5 specimens, the inflammatory reaction went from acute to moderate. In relation to Group 4 specimens, an organized bone formation process was observed.

CONCLUSIONS

Specimens from Group 2 showed higher biocompatibility, especially as compared with the specimens from Groups 3 and 5.

To evaluate the biocompatibility of the Indian Portland cement with potential for use in dentistry: An animal study

Aims:

This study evaluated the biocompatibility of the Indian Portland cement with potential for use in dentistry.

Materials and Methods:

This study was performed in Swiss albino mice, by implanting the Indian Portland cement pellets subcutaneously. After 1, 3, and 6 weeks the tissue specimens were prepared for histological examination.

Results:

The histological analysis showed moderate to severe inflammation at 1 week. The inflammation gradually decreased by 6 weeks, with most of the specimens showing the absence of inflammatory reaction.

Conclusions:

According to these experimental conditions, the tested Indian Portland cement was biocompatible.

Biocompatibility of a new epoxy resin-based root canal sealer in subcutaneous tissue of rat

Objective:

The objective was to evaluate the subcutaneous biocompatibility of two root canal sealers.

Materials and Methods:

Thirty female rats were distributed into two groups of 15 animals. Each received subcutaneous dorsal implants: Silicone tubes filled with AH Plus or Obtuseal. After the 11^th, 14^th, and 45^th days, tissues were collected for biopsy and fixed and processed for histologic evaluation. Observations of the cellular inflammatory components, such as lymphocytes and macrophages, were made. The data were analyzed using Kruskal–Wallis and Connover tests (P < 0.05).

Results:

By the 7^th day, lymphocyte infiltration increased in both groups (P = 0.0104). However, macrophage infiltration increased only in the AH Plus group (P = 0.0011). By the 14^th and 45^th days, lymphocyte and macrophage infiltrations were reduced. At the end of the experimental period, no statistically significant differences were found between the AH Plus group and the Obtuseal group (P > 0.05).

Conclusion:

After 45 days, Obtuseal yielded a satisfactory tissue reaction; it was biocompatible when tested in subcutaneous rat tissue. On the basis of the obtained results, it was concluded that Obtuseal root canal sealer caused a satisfactory tissue reaction as AH plus, because it was biocompatible when tested in the subcutaneous tissue of rats.

Comparison of cytotoxicity of various concentrations origanum extract solution with 2% chlorhexidine gluconate and 5.25% sodium hypochlorite

Objective:

The purpose of this in vitro study was to compare the cytotoxicity of 0.5–4.5 origanum extract solution (OES), 2% chlorhexidine gluconate (CHX) and 5.25% sodium hypochlorite (NaOCl) with WST-1 test on human periodontal ligament (hPDL) fibroblasts.

Materials and Methods:

About 0.5–4.5% OES, 2% CHX and 5.25% NaOCl solutions cytotoxicity was evaluated with cell culture test using PDL fibroblasts. Viability of hPDL cells was evaluated with WST-1 (Cell Proliferation Reagent WST-1 Roche) test at 1, 24 and 72^nd h. hPDL cells were plated at 20 × 10³ cells per well in 96-well plates. Absorbance values were read in optical density 480 nm by ELISA plate reader spectrophotometer. The statistical differences between various groups were evaluated using one-way ANOVA, post-hoc Duncan's Multiple Range test using SAS software. Statistically, a significant difference was considered at P < 0.001.

Results:

According to the 1-h cytotoxicity results, 0.5% OES showed the least cytotoxic effect in test groups. There were not found any statistical significance between 1% OES and 2% CHX. About 5.25% NaOCl showed more cytotoxic effect than 1% OES and 2% CHX. In 24 and 72 h, different concentrations of OES, 5.25% NaOCl, 2% CHX solutions showed similar cytotoxic effect.

Conclusions:

Based on these results, 1% OES and 2% CHX showed similar results and less cytotoxic effect than 5.25% NaOCl. It could be considered as a favorable solution concentration when OES was used as root canal irrigation solution.

Antimicrobial activity of different filling pastes for deciduous tooth treatment

Guedes-Pinto paste is the filling material most employed in Brazil for endodontic treatment of deciduous teeth; however, the Rifocort® ointment has been removed. Thus, the aim of this study was to investigate the antimicrobial potential of filling pastes, by proposing three new pharmacological associations to replace Rifocort® ointment with drugs of already established antimicrobial power: Nebacetin® ointment, 2% Chlorhexidine Gluconate gel, and Maxitrol® ointment. A paste composed of Iodoform, Rifocort® ointment and Camphorated Paramonochlorophenol (CPC) was employed as the gold standard (G1). The other associations were: Iodoform, Nebacetin® ointment and CPC (G2); Iodoform, 2% Chlorhexidine Digluconate gel and CPC (G3); Iodoform, Maxitrol® ointment and CPC (G4). The associations were tested for Staphylococcus aureus (S. aureus), Streptococcus mutans (S. mutans), Streptococcus oralis (S. oralis), Enterococcus faecalis (E. faecalis), Escherichia coli (E. coli), and Bacillus subtilis (B. subtilis), using the methods of dilution on solid medium - orifice agar - and broth dilution. The results were tested using statistical analysis ANOVA and Kruskal-Wallis. They showed that all the pastes had a bacteriostatic effect on all the microorganisms, without any statistically significant difference, compared with G1. S. aureus was statistically significant (multiple comparison test of Tukey), insofar as G2 and G3 presented the worst and the best performance, respectively. All associations were bactericidal for E. coli, S. aureus, S. mutans and S. oralis. Only G3 and G4 were bactericidal for E. faecalis, whereas no product was bactericidal for B. subtilis. Thus, the tested pastes have antimicrobial potential and have proved acceptable for endodontic treatment of primary teeth.