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Aim: The purpose of this in vitro study was to evaluate the antimicrobial activity of 2% chlorhexidine gel (CHX) as auxiliary chemical substance and intracanal medications on Candida albicans, Enterococcus faecalis, Escherichia coli, and their endotoxins in the root canals., Materials and Methods: The study was conducted on 48 single-rooted human teeth divided into four groups (n = 12), according to intracanal medications used: (1) Calcium hydroxide + apyrogenic saline solution (Ca(OH)2 + SS), (2) 20% ginger glycolic extract (GEN), (3) calcium hydroxide + 20% ginger glycolic extract (Ca(OH)2 + GEN), (4) apyrogenic SS (control). Collections were made from the root canal content before preparation (baseline-S1), immediately after instrumentation (S2), 7 days after instrumentation (S3), after 14 days the action of intracanal medication (S4), and 7 days after removal of the intracanal medication (S5). The antimicrobial activity and endotoxin content were analyzed for all collections. The results were statistically analyzed by the Kruskal-Wallis and Dunn tests at a significance level of 5%., Results: After instrumentation with CHX, there was complete elimination of E. coli and C. albicans, except for E. faecalis, which was significantly reduced and then completely eliminated after intracanal medication. There was significant reduction of endotoxin after instrumentation. Comparison of collection after instrumentation and intracanal medication revealed reduction of endotoxins in all groups; this reduction was greater in group Ca(OH)2 followed by the group GEN., Conclusion: It was concluded that the instrumentation using CHX and intracanal medication used were able to eliminate the microorganisms from the root canal; the endotoxins were reduced, yet not completely eliminated., Clinical Significance: This study is important and relevant for searching alternatives during endodontic therapy, since it aims to study the effect of Zingiber officinale on microorganisms and endotoxins present in root canals.

Introduction: This clinical study aimed to determine the microbiological profile resistant to different intracanal medications in primary endodontic infections by using both microbiological culture and the checkerboard DNA-DNA hybridization technique., Methods: Twenty primarily infected root canals were selected and then instrumented before being randomly divided into 2 groups according to the intracanal medications: calcium hydroxide (Ca[OH]2) or Ca(OH)2 + chlorhexidine (CHX). Samples were collected before and after root canal procedures, which consisted in submitting them to microbiological culture and processing them for checkerboard DNA-DNA hybridization., Results: No differences were found between the Ca(OH)2 (99.98%) and Ca(OH)2 + CHX groups (99.76%) regarding the median percentage values for the reduction of cultivable bacteria. The most frequently detected species were Capnocytophaga ochracea (70%) and Fusobacterium nucleatum ssp. vincentii (70%) in the initial samples. After instrumentation, the most frequently detected species were E. faecium (60%). After root canal treatments using either Ca(OH)2 or Ca(OH)2 + CHX as intracanal medications, the most frequently detected species were F. nucleatum ssp. vincentii (90%) and Enterococcus faecium (40%), respectively. Both treatments significantly decreased the number of bacterial species compared with the initial sample. However, this reduction was significantly greater in the Ca(OH)2 + CHX group (P < .05). This difference was also observed when evaluating the total bacterial load (P < .05)., Conclusions: The use of Ca(OH)2 associated with CHX as an intracanal medication showed better results by acting on gram-positive and gram-negative microorganisms although such an action to eradicate enterococci should also be sought., (Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

Introduction: This study compared the influence of different irrigants with and without ultrasound or laser irradiation on the bond strength of glass fiber posts using a self-etching adhesive in a supplementary dentin pretreatment., Methods: Ninety bovine incisor roots were divided into 3 groups according to the irrigant tested: 2% chlorhexidine (CHX) (n = 30); 2.5% sodium hypochlorite (NaOCl) (n = 30), and saline solution (control) (n = 30). Each group was randomly divided into 3 subgroups according to the supplementary dentin pretreatment: ultrasound, Nd:YAG laser, and nonsupplemented (control). A self-etching adhesive system (Futurabond DC; VOCO GmbH, Cuxhaven, Germany) was used, and the glass fiber posts were cemented with dual-cure epoxy-based luting agent (Bifix QM, VOCO GmbH). All roots were sectioned transversely, and the push-out test was performed. Failure mode analysis was also evaluated., Results: Bond strength decreased significantly after the use of 2.5% NaOCl in all root thirds (P < .05). CHX showed no difference in the mean bond strength value compared with saline solution (P > .05). The supplementary dentin pretreatment using the Nd:YAG laser or ultrasound did not improve the bond strength values for both NaOCl and CHX (P > .05). Moreover, the apical third exhibited the lowest mean bond strength values (P < .05). Analysis indicated that the predominant failure mode was the mixed type., Conclusions: Regardless of the irrigant used, the supplementary dentin pretreatment with ultrasound or laser irradiation showed no improvement in bond strength. Also, the use of NaOCl decreased the bond strength of glass fiber posts using a self-etching adhesive system, whereas CHX preserved it., (Copyright © 2015 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

Objective: This study was conducted in vitro to compare the effectiveness of Zingiber Officinale as an auxiliary chemical substance followed by placement of different intra-canal medication in removing endotoxins and cultivable micro-organisms from infected root canals., Materials and Methods: Seventy-two root canals were contaminated with Enterococcus faecalis, Candida albicans and Escherichia coli for 28 days. After, the teeth were instrumented using Zingiber Officinale and divided into six groups according to the intra-canal medication: chlorhexidine gel; calcium hydroxide + chlorhexidine gel; glycolic ginger extract; calcium hydroxide + glycolic ginger extract; calcium hydroxide + saline solution and saline solution (control). Sample collections were performed after root canal contamination (Baseline; S1), after instrumentation (S2), 7 days after instrumentation (S3), after 14 days with intra-canal medication (S4) and 7 days after removal of intra-canal medication (S5). The results were analyzed by the Kruskal-Wallis and Dunn tests., Results: It was observed that in S2 and S3 there was significant reduction of the micro-organisms and the quantity of endotoxins after instrumentation. In samples S4 and S5 there was complete elimination of micro-organisms and significant reduction of endotoxins., Conclusion: It was concluded that Zingiber Officinale as an auxiliary chemical substance was effective on the micro-organisms tested, yet was unable to eliminate the endotoxins. Similarly, the intra-canal medication were effective on micro-organisms, yet did not completely eliminate the endotoxins.

Introduction: This clinical study was conducted to compare the effectiveness of 1-visit versus 2-visit root canal treatment in removing endotoxins and cultivable bacteria from primarily infected root canals., Methods: Forty-eight primarily infected root canals were selected and randomly divided into 4 groups: G1, 1% NaOCl; G2, 2% chlorhexidine (CHX) gel; G3, 1% NaOCl + Ca(OH)2; and G4, 2% CHX gel + Ca(OH)2 (all, n = 12). G1 and G2 involved 1-visit treatment, whereas G3 and G4 involved 2-visit treatment with the placement of Ca(OH)2 medication for 14 days. Samples were collected before and after root canal procedures. A chromogenic LAL assay test was used to quantify endotoxins. Culture techniques were used to determine bacterial counts., Results: Endotoxins and cultivable bacteria were detected in 100% of the initial samples. All treatment protocols were effective in reducing bacterial load from infected root canals: G1 (1% NaOCl, 99.97%), G2 (2% CHX gel, 99.75%), G3 (1% NaOCl + Ca(OH)2, 99.90%), and G4 (2% CHX gel + Ca(OH)2, 96.81%), respectively (P < .05). No differences were found in bacterial load reduction when comparing 1-visit and 2-visit treatment groups, irrespective of the irrigant tested (P > .05). Higher median percentage values of endotoxin reduction were achieved in the 2-visit treatment groups (G3, 98.01% and G4, 96.81%) compared with 1-visit treatment groups (G1, 86.33% and G2, 84.77%) (all P < .05)., Conclusions: Both 1-visit and 2-visit root canal treatment protocols were effective in reducing bacteria and endotoxins, but they were not able to eliminate them in all root canals analyzed. Furthermore, 2-visit root canal treatment protocols were more effective in reducing endotoxins than 1-visit root canal treatment protocols., (Copyright © 2013 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

Objective: The aim of this study was to evaluate the antimicrobial activity of auxiliary chemical substances and natural extracts on Candida albicans and Enterococcus faecalis inoculated in root canals., Material and Methods: Seventy-two human tooth roots were contaminated with C. albicans and E. faecalis for 21 days. The groups were divided according to the auxiliary chemical substance into: G1) 2.5% sodium hypochlorite (NaOCl), G2) 2% chlorhexidine gel (CHX), G3) castor oil, G4) glycolic Aloe vera extract, G5) glycolic ginger extract, and G6) sterile saline (control). The samples of the root canal were collected at different intervals: confirmation collection, at 21 days after contamination; 1st collection, after instrumentation; and 2nd collection, seven days after instrumentation. Microbiological samples were grown in culture medium and incubated at 37°C for 48 hours., Results: The results were submitted to the Kruskal-Wallis and Dunn (5%) statistical tests. NaOCl and CHX completely eliminated the microorganisms of the root canals. Castor oil and ginger significantly reduced the number of CFU of the tested bacteria. Reduction of CFU/mL at the 1st and 2nd collections for groups G1, G2, G3 and G4 was greater in comparison to groups G5 and G6., Conclusion: It was concluded that 2.5% sodium hypochlorite and 2% chlorhexidine gel were more effective in eliminating C. albicans and E. faecalis, followed by the castor oil and glycolic ginger extract. The Aloe vera extract showed no antimicrobial activity.

Introduction: Endotoxins are one of the etiologic agents involved in the pathogenesis of apical periodontitis. The objectives of this clinical study were to investigate the effects of endodontic treatment by using different irrigants on endotoxins in root canals with pulp necrosis and apical periodontitis and to evaluate the cytotoxic effects., Methods: Thirty-six root canals were selected. Samples were collected before (S1) and after instrumentation (S2). The root canals were divided into 3 groups (n = 12) according to the irrigant combination used: CLX + LW, 2% chlorhexidine gel + calcium hydroxide (0.14%, limewater); CLX + PmB, chlorhexidine + polymyxin B; CLX (control), chlorhexidine + saline. The third sampling (S3) was performed after ethylenediaminetetraacetic acid and S4 after intracanal medication (CLX + calcium hydroxide for 14 days). Endotoxins were quantified by the chromogenic Limulus amebocyte lysate assay, and cytotoxic effects were evaluated by the production of cytokines (interleukin-1ß, tumor necrosis factor α) in macrophages (RAW 264.7) stimulated with the root canal content., Results: Endotoxins were detected in all root canals before instrumentation (S1). Group CLX + LW presented the greatest endotoxin reduction after instrumentation (99.18%), which was similar to group CLX + PmB (96.42%, P > .05) and different from group CLX (90.78%, P < .05). The intracanal medication promoted important endotoxin neutralization, with a reduction of 99.2% to 100%. The root canal content induced a higher production of tumor necrosis factor α and interleukin-1β in S1 samples compared with samples obtained after treatment., Conclusions: The combination of CLX and limewater as irrigant was the most effective in reducing endotoxins in root canals, and intracanal medication was important to neutralize the cytotoxic effects., (Copyright © 2012 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

Objective: The purpose of this study was to evaluate the efficacy of auxiliary chemical substances and intracanal medications on Escherichia coli and its endotoxin in root canals., Material and Methods: Teeth were contaminated with a suspension of E. coli for 14 days and divided into 3 groups according to the auxiliary chemical substance used: G1) 2.5% sodium hypochlorite (NaOCl); G2) 2% chlorhexidine gel (CLX); G3) pyrogen-free solution. After, these groups were subdivided according to the intracanal medication (ICM): A) Calcium hydroxide paste (Calen®), B) polymyxin B, and C) Calcium hydroxide paste+2% CLX gel. For the control group (G4), pyrogen-free saline solution was used without application of intracanal medication. Samples of the root canal content were collected immediately after biomechanical preparation (BMP), at 7 days after BMP, after 14 days of intracanal medication activity, and 7 days after removal of intracanal medication. The following aspects were evaluated for all collections: a) antimicrobial activity; b) quantification of endotoxin by the Limulus Amebocyte Lysate test (LAL). Results were analyzed by the Kruskal-Wallis and Dunn's tests at 5% significance level., Results: The 2.5% NaOCl and CLX were able to eliminate E. coli from root canal lumen and reduced the amount of endotoxin compared to saline., Conclusions: It was concluded that 2.5% NaOCl and CLX were effective in eliminating E. coli. Only the studied intracanal medications were to reduce the amount of endotoxin present in the root canals, regardless of the irrigant used.

Objective: The aim of this study was to evaluate, by scanning electronic microscopy (SEM), the cleaning of the root canal walls after instrumentation and irrigation with 2.5% sodium hypochlorite (NaOCl) associated with 2% chlorhexidine (CHX) gel or liquid, combined or not with 17% ethylenediamine tetra-acetic acid (EDTA)., Study Design: Sixty single-root human teeth were subjected to standardized root canal instrumentation with different irrigants (n = 10): G1) NaOCl + CHX liquid; G2) NaOCl + CHX liquid + EDTA + saline solution; G3) NaOCl + CHX gel; G4) NaOCl + CHX gel + EDTA + saline solution; G5) saline solution; G6) saline solution + EDTA. After instrumentation, the teeth were prepared for SEM analysis (×500 and ×2,000) to evaluate the cleaning of the cervical, middle, and apical thirds. The area analyzed was quantified according to the percentage of open and closed tubules, and data were statistically analyzed by analysis of variance and Tukey tests (P = .05)., Results: The number of open tubules was highest in G4 in all root thirds, showing statistically significant difference from G1, G2, and G5 (P < .05). G1 presented higher quantity of closed tubules significant than G2., Conclusion: Irrigation with NaOCl and CHX gel followed by EDTA and saline solution produced greater cleaning of the root canal walls., (Copyright © 2010 Mosby, Inc. All rights reserved.)

This study evaluated the action of propolis and intracanal medications against Escherichia coli and endotoxin. Forty-eight dental roots were contaminated with E. coli. The root canals were instrumented with propolis and divided into groups according to the type of intracanal medication: Ca(OH)(2), polymyxin B, or Ca(OH)(2) + 2% chlorhexidine gel. In the control group, saline solution was used without application of intracanal medication. Counts of colony-forming units were carried out and the endotoxin was quantified by the chromogenic Limulus amobocyte lysate assay. The results were evaluated by analysis of variance and the Dunn test (5%). Root canal irrigation with propolis was effective to completely eliminate E. coli and reduce the amount of endotoxins. All intracanal medications contributed to the significant decrease in endotoxins. Only intracanal medications may reduce the amount of endotoxins in the root canals. The greatest efficacy was observed for medications containing Ca(OH)(2)., (Copyright © 2010. Published by Mosby, Inc.)

Objective: The purpose of this study was to evaluate the action of sodium hypochlorite (NaOCl) associated with an intracanal medication against Candida albicans and Enterococcus faecalis inoculated in root canals., Material and Methods: Thirty-six human single-rooted teeth with single root canals were used. The canals were contaminated with C. albicans and E. faecalis for 21 days and were then instrumented with 1% NaOCl. The roots were divided into 3 groups (n=12) according to the intracanal medication applied: calcium hydroxide paste, 2% chlorhexidine (CHX) gel, and 2% CHX gel associated with calcium hydroxide. The following collections were made from the root canals: a) initial sample (IS): 21 days after contamination (control), b) S1: after instrumentation, c) S2: 14 days after intracanal medication placement; S3: 7 days after intracanal medication removal. The results were analyzed statistically by the Kruskal-Wallis test at 5% significance level., Results and Conclusions: Both 1% NaOCl irrigation and the intracanal medications were effective in eliminating E. faecalis and C. albicans inoculated in root canals.

This study compared the effect of two drills and five cleaning regimens on post space debridement. One hundred extracted premolars were instrumented and obturated with warm vertical compaction of gutta percha. The teeth were divided into two groups according to the drill used to remove gutta percha/sealer and for post space preparation: a Largo drill (Largo; Dentsply, St Quentin en Yvelines, France) or a MTwo-PF drill (Sweden&Martina, Due Carrare, Padova, Italy). The following cleaning regimens were used: EDTA, ultrasonics, ultrasonics + EDTA, phosphoric acid, and distilled water. Scanning electron microscopic images of the post spaces were taken, and the presence of debris and of open dentin tubules were evaluated. The ultrasonics + EDTA, phosphoric acid, and EDTA groups were comparable in open tubules scores for both drills and in debris scores after the use of MTwo-PF (p > 0.05). The ultrasonics and control groups performed significantly worse (p < 0.05). The MTwo-PF drill resulted as effective as the Largo drill in obtaining a good post space cleaning, especially when followed by ultrasonics + EDTA irrigant regimen.

Objective: The purpose of this study was to evaluate the effects of endodontic irrigants on the microhardness of root canal dentin., Study Design: Thirty extracted single-rooted human teeth were used. The crowns were sectioned at the cementoenamel junction. Each root was transversely sectioned into cervical, middle, and apical segments, resulting in 90 specimens. The 3 sections of each root were separately mounted in an individual silicon device with acrylic resin. The specimens were randomly divided into the following 3 groups (n = 30), according to the irrigant solution used: (1) group 1, control (saline solution); (2) group 2, 2% chlorhexidine gluconate solution; and (3) group 3, 1% sodium hypochlorite (NaOCl). After 15 minutes of irrigation, dentin microhardness was measured on each section at 500 microm and 1000 microm from the pulp-dentin interface with a Vickers diamond microhardness tester in Vickers hardness number (VHN)., Results: Data obtained were analyzed using analysis of variance and the Tukey test (5%). Specimens irrigated with 2% chlorhexidine (group 2) or 1% NaOCl (group 3) presented lower values of dentin microhardness, with significant difference in relation to the control group (P < .05)., Conclusion: It could be concluded that chlorhexidine and NaOCl solutions significantly reduced the microhardness of root canal dentin at 500 microm and 1000 microm from the pulp-dentin interface.

Objective: The objective of this study was to evaluate the effects of endodontic irrigants on endotoxins in root canals., Study Design: Ninety-eight single-root human teeth were used. Escherichia coli endotoxin was inoculated into 84 root canals. All root canals were enlarged and assigned to 7 groups (n = 14), according to solution used. Group 1 (G1): 2.5% NaOCl; G2: 5.25% NaOCl; G3: 2% chlorhexidine; G4: 0.14% calcium hydroxide; G5: polymyxin B; G6: positive control, saline solution; G7: negative control (no endotoxin). Two samplings of root canal were accomplished: immediate and after 7 days. Detoxification of endotoxin was evaluated by Limulus assay and antibody production in B-lymphocyte culture. Results were analyzed by Kruskal-Wallis/Dunn and ANOVA/Tukey., Results: At the immediate and second samplings, groups G4, G5, and G7 presented the best results, significantly different from groups G1, G2, G3, and G6 (P < .05)., Conclusions: Calcium hydroxide and polymyxin B detoxified endotoxin in root canals and altered properties of LPS to stimulate the antibody production by B-lymphocytes. Sodium hypochlorite and chlorhexidine did not detoxify endotoxin.

Objectives: To evaluate the effects of intracanal medicaments on endotoxins in root canals., Methods: Seventy-five freshly extracted maxillary incisors were used in this study. The crowns of teeth were sectioned near the CEJ in order to standardize the root length to 14 mm. The root canals were instrumented to an apical size #50 file and irrigated with 1% sodium hypochlorite solution and sterilized with 60Co gamma irradiation. Standardized suspension containing Escherichia coli endotoxin was inoculated into the 60 root canals. The specimens were randomly assigned to 5 groups (n=15), according to the intracanal medicament used: (G1) calcium hydroxide; (G2) polymyxin B; (G3) combination neomycin-polymyxin B-hydrocortisone; (G4) positive control (no intracanal medicament); (G5) negative control (no endotoxin and no intracanal medicament). After 7 days, the detoxification of endotoxin was evaluated by Limulus lysate assay and antibody production in B-lymphocytes culture., Results: Groups 1, 2 and 5 presented the best results by Limulus lysate and were significantly different to groups 3 and 4 (p<0.05). Stimulation of antibodies production in cell culture by groups 1 and 6 was smaller and statistically different than groups 2, 3, 4 and 5 (p<0.05). Groups 2 and 5 induced a small increase in the antibodies production in relation to the groups 1 and 6. Groups 3 and 4 induced a significant increase of antibodies production (p<0.05)., Conclusions: The calcium hydroxide and polymyxin B intracanal medicaments detoxified endotoxin in root canals and altered the properties of LPS to stimulate the antibody production by B-lymphocytes. The combination neomycin-polymyxin B-hydrocortisone did not detoxified endotoxin.