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Yang SE, Cha JH, Kim ES, Kum KY, Lee CY, Jung IY. Effect of smear layer and chlorhexidine treatment on the adhesion of Enterococcus faecalis to bovine dentin. J Endod 2006; 32:663-7. [PMID: 16793476 DOI: 10.1016/j.joen.2005.12.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2005] [Revised: 11/22/2005] [Accepted: 12/01/2005] [Indexed: 11/19/2022]
Abstract
The aim of this in vitro study was to determine the effects of a smear layer and chlorhexidine (CHX) treatment on the adhesion of Enterococcus faecalis to bovine dentin. Forty dentin blocks from bovine incisors were prepared and randomly divided into four groups of 10 each. The blocks in group 1 were placed in sterile saline for 5 minutes, while those in group 2 were treated with 17% EDTA for 5 minutes. The blocks in group 3 were placed in 2% CHX for 7 days. The blocks in group 4 were treated with 17% EDTA for 5 minutes, and then placed in 2% CHX for 7 days. All the blocks were immersed in a suspension of E. faecalis for 3 hours. The bacteria adhering to the dentin surface were counted by examination using a scanning electron microscope. The most significant amount of bacteria was retained on the samples from group 1 (p < 0.05) and the smallest amount of bacteria adhered to the samples from group 4. These results suggest that a smear layer enhances the adherence of E. faecalis to the dentin, and CHX is effective in reducing the adherence of microorganisms.
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Affiliation(s)
- Seung-Eun Yang
- Department of Conservative Dentistry, College of Dentistry, Yonsei University, Seodaemun-gu, Seoul, Republic of Korea
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102
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Vezzani MS, Pietro R, Silva-Sousa YT, Brugnera-Junior A, Sousa-Neto MD. Disinfection of Root Canals Using Er:YAG Laser at Different Frequencies. Photomed Laser Surg 2006; 24:499-502. [PMID: 16942431 DOI: 10.1089/pho.2006.24.499] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
OBJECTIVE This study evaluated, in vitro, the degree of disinfection of the Er:YAG laser in root canals contaminated with Bacillus subtilis, Staphylococcus aureus, Enterococcus faecalis, Pseudomonas aeruginosa, and Candida albicans, for 28 days. METHODS Forty-six single-rooted human teeth were divided into five groups of eight teeth each; three teeth were used as negative controls and three as positive controls. After contamination, the root canals were prepared mechanically. Three groups were irradiated with Er:YAG laser at 100 mJ, varying the frequency (7, 10, and 16 Hz). Two groups were irrigated with 1.0% and 2.5% NaOCl solution. After treatment, two sterilized paper cones were placed in the root canals for 5 min. One cone was transferred to 2.0 mL of Letheen broth culture medium, incubated at 37 degrees C for 48 h, and then 0.1 mL of that solution was placed in 2.0 mL of brain heart infusion for 48 h to determine microbial growth. The other cone was transferred to a test pipette with peptone and water for serial dilution and spread in Müeller Hinton medium. After 24 h of incubation, the colony-forming units (CFUs) were counted. RESULTS There was a microbial reduction of 85.33% for the group irradiated with Er:YAG laser at 100 mJ/7 Hz, 74.58% at 100 mJ/10 Hz, and 89.50% at 100 mJ/16 Hz. For the groups irrigated with 1.0% and 2.5% NaOCl solution, 83.15% and 84.46% values of microbial reduction were obtained respectively. CONCLUSION All the groups showed statistically similar results (p > 0.05%). No method totally eliminated microorganisms.
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103
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Bonsor SJ, Nichol R, Reid TMS, Pearson GJ. An alternative regimen for root canal disinfection. Br Dent J 2006; 201:101-5; discussion 98; quiz 120. [PMID: 16865142 DOI: 10.1038/sj.bdj.4813819] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/14/2005] [Indexed: 11/09/2022]
Abstract
OBJECTIVE To compare the effect of a combination of 20% citric acid solution and photo-activated disinfection with the use of 20% citric acid and 2.25% sodium hypochlorite solutions on bacterial load on the dentine walls in prepared canals in vivo. SUBJECTS AND METHODS Sixty-four randomly selected cases were evaluated and allocated to one of two groups. In Group 1, after gaining access to the root canal, bacterial load on the canal walls was sampled using endodontic files. A further sample was taken after apex location and initial widening of the canal had been completed and the photo-activated disinfection process carried out. A final sample was taken after completion of the canal preparation using citric acid and sodium hypochlorite solutions. In Group 2, the initial sample was taken as described previously. A second sample was taken after conventional preparation using 20% citric acid and sodium hypochlorite solutions as co-irrigants. A final sample was then taken after a subsequent PAD treatment. All samples were cultured for facultative anaerobic bacteria. RESULTS Of the canals treated in Group 1 only two of the 23 canals infected showed culturable bacteria after the use of citric acid and photo-activated disinfection. Of these two canals, one was free of culturable bacteria on completion of conventional treatment but the other still contained culturable bacteria. In Group 2, four canals of the 23 infected initially, remained contaminated after conventional treatment. After subsequent photo-activated disinfection three of these four canals were free of culturable bacteria. CONCLUSION Results indicate that the use of a chelating agent acting as a cleaner and disrupter of the biofilm and photo-activated disinfection to kill bacteria is an effective alternative to the use of hypochlorite as a root canal cleaning system.
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Affiliation(s)
- S J Bonsor
- The Dental Practice, 21 Rubislaw Terrace, Aberdeen AB10 1XE, and Department of biomaterials in Relation to Dentistry, Barts and London School of Medicine and Dentistry, Queen Mary University of London, UK.
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104
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Williams JA, Pearson GJ, Colles MJ. Antibacterial action of photoactivated disinfection {PAD} used on endodontic bacteria in planktonic suspension and in artificial and human root canals. J Dent 2006; 34:363-71. [PMID: 16239058 DOI: 10.1016/j.jdent.2005.08.002] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2005] [Revised: 08/25/2005] [Accepted: 08/26/2005] [Indexed: 10/25/2022] Open
Abstract
OBJECTIVES To measure antibacterial action of photoactivated disinfection (PAD) on endodontic bacteria in planktonic suspension and root canals. METHODS Four bacteria, Fusobacterium nucleatum,Peptostreptococcus micros, Prevotella intermedia and Streptococcus intermedius, were tested in suspension. After mixing equal volumes of Tolonium chloride and bacterial suspension for 60s, each 200 microL of concentration (>10(6)cfu mL(-1)) was irradiated with light at 633+/-2 nm. Each energy dose/Tolonium chloride concentration combination was tested eight times, with controls. Prepared root canals in Training Blocs and extracted human teeth were inoculated with S. intermedius followed by 10 mg L(-1) Tolonium chloride or saline. Bacteria in canals were sampled before and after light irradiation. Student t-test assessed significance of changes in viable bacteria produced by treatment of either light or Tolonium chloride alone and light/Tolonium chloride combinations. RESULTS In suspension, reductions in bacteria were highly significant (P<0.01) for light/Tolonium chloride combinations compared to light or Tolonium chloride alone. Maximum mean log reductions of 1.14 (P. intermedia), 2.48 (P. micros), 2.81 (F. nucleatum) and 6.73 (S. intermedius) were at 4.8 J/20 mg L(-1). Antibacterial action was increased by energy dose increase (not always significantly), but not by Tolonium chloride concentration. In control canals mean log reductions of 0.42 (Blocs) and 0.38 (teeth) from initial levels were not significant. PAD mean log reductions of 2.40 (Blocs) and 2.01 (teeth) were highly significant. Changes for PAD/energy dose combinations were not significant. CONCLUSION PAD killed endodontic bacteria at statistically significant levels compared to controls. Kills varied with bacterial species.
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Affiliation(s)
- Jill A Williams
- Department of Biomaterials in Relation to Dentistry, Medical Science Building, Queen Mary University of London, Mile End Road, London E1 4NS, UK.
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105
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Khademi A, Yazdizadeh M, Feizianfard M. Determination of the Minimum Instrumentation Size for Penetration of Irrigants to the Apical Third of Root Canal Systems. J Endod 2006; 32:417-20. [PMID: 16631839 DOI: 10.1016/j.joen.2005.11.008] [Citation(s) in RCA: 117] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2005] [Revised: 11/06/2005] [Accepted: 11/09/2005] [Indexed: 11/22/2022]
Abstract
The purpose of this study was to determine the minimum instrumentation size required for the effective penetration of irrigants and elimination of debris and smear layer from the apical third of the root canals. The mesiobuccal canals of 40 freshly extracted human mandibular first molar teeth were instrumented using the crown-down technique. The teeth were divided into four test groups according to the size of their Master Apical File (#20, #25, #30, #35), and two control groups. After final irrigation, the removal of debris and smear layer from the apical third of root canals was determined under a scanning electron microscope. The data was analyzed using Kruskal-Wallis and Mann-Whitney tests. Based on the results, it appears that the minimum instrumentation size needed for penetration of irrigants to the apical third of the root canal is a #30 file.
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Affiliation(s)
- Abbasali Khademi
- Department of Endodontics, School of Dentistry, Isfahan Medical University, Iran.
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106
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Soares JA, Pires Júnior DR. Influence of sodium hypochlorite-based irrigants on the susceptibility of intracanal microbiota to biomechanical preparation. Braz Dent J 2006; 17:310-6. [PMID: 17262145 DOI: 10.1590/s0103-64402006000400009] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2006] [Accepted: 08/29/2006] [Indexed: 11/21/2022] Open
Abstract
This study evaluated the microbiological conditions of root canals, using smears and culture from anterior teeth and premolars with necrotic pulps associated with chronic periapical pathologies, before and after biomechanical preparation (BMP). During double-flared instrumentation, 1, 2.5 and 5% sodium hypochlorite (NaOCl)-based irrigants were used in 3 groups: GI (n=39), GII (n=36) and GIII (n=36), respectively. Before BMP, all cultures were positive and the smears showed microbiologically diverse morphotypes, including fusiforms, pleomorphic, rods, cocci and filaments. Quantitetively, 20, 20 and 23 morphotypes were identified in GI, GII and GIII, respectively). After BMP, the percentages of negative cultures in GI, GII and GIII were 74.2%, 86.3% and 93.4% (p>0.05) and the number of morphotypes decreased to 14, 15 and 5, respectively. All teeth with 2 root canals and/or associated fistulas were microbiologically negative after BMP, regardless of irrigant concentration. Gram-negative morphotypes were more susceptible to the action of irrigants. After irrigation with 5% NaOCl, only structural arrangements consisting of Gram-positive cocci and bacilli persisted. Thus, BMP plus 5% NaOCl offered the best antiseptic potential because in the few positive cultures a significant reduction in the number of microbiological morphotypes was also shown (p<0.05).
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Affiliation(s)
- Janir Alves Soares
- Department of Dentistry, Federal University of Vales do Jequitinhonha e Mucuri, Rua da Glória 187, 39100-00 Diamantina, MG, Brazil.
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107
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Abstract
This in vivo study evaluated, through the physicochemical assay method for quantification of enhanced vascular permeability, the irritating potential of EDTA, EGTA, citric acid and saline. Thirty-two male Wister rats were anesthetized and four experimental sites were demarcated on their backs. Injections of 2% Evans blue (20 mg/kg) were administered intravenously into the lateral caudal vein. The test solutions were immediately injected intradermally (0.01 mL) into the experimental sites. The animals were killed 30 min, 1, 3 and 6 h after injection of the solutions and each piece of skin was submerged in formamide and incubated at 45 masculineC for 72 h. After filtration, the optical density was measured in a spectrophotometer and the total amount of dye extracted from the samples was calculated by means of a standard calibration curve. Data were analyzed statistically by two-way ANOVA and Tukey's HSD test. Compared to control, EDTA had the greatest volume of dye followed by EGTA and citric acid, for all time periods. There were statistically significant differences between all solutions (p<0.01). Considering the periods assessed, a significant difference was observed between the 3- and 6-h groups (p<0.05), but not between the 30-min and 1-h groups. Among the organic acids evaluated in this study, citric acid yielded the lowest amount of extracted dye. This indicates that the citric acid was the least irritating solution.
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108
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Carson KR, Goodell GG, McClanahan SB. Comparison of the antimicrobial activity of six irrigants on primary endodontic pathogens. J Endod 2005; 31:471-3. [PMID: 15917691 DOI: 10.1097/01.don.0000148868.72833.62] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The purpose of this study was to compare the antimicrobial activities of 6% and 3% sodium hypochlorite (NaOCl), 2% and 0.12% chlorhexidine gluconate (CHX), and 0.01% and 0.005% doxycycline (Doxy) on four microorganisms associated with primary endodontic infections. The agar diffusion test was used to measure antimicrobial activities of these agents against Peptostreptococcus micros, Prevotella intermedia, Streptococcus sanguis, and Lactobacillus acidophilus. Minimum inhibitory concentration analysis was performed using the macrodilution method. For three of the four microorganisms, the general order of antimicrobial effectiveness was 0.01% Doxy >0.005% Doxy >6% NaOCl >3% NaOCl >2% CHX > 0.12% CHX. For L. acidophilus, the order of effectiveness was 6% NaOCl >3% NaOCl >2% CHX > 0.01% Doxy >0.005% Doxy >0.12% CHX. The 6% NaOCl showed significantly greater zones of inhibition than 3% NaOCl for all endopathogens tested.
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109
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Siqueira JF. Reaction of periradicular tissues to root canal treatment: benefits and drawbacks. ACTA ACUST UNITED AC 2005. [DOI: 10.1111/j.1601-1546.2005.00134.x] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
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110
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Abstract
The influence of dentin on the effectiveness of three antibacterial agents (triclosan, glutaraldehyde, NaOCl) on Streptococcus mutans, S. sobrinus, and Lactobacillus acidophilus was tested using the agar diffusion method with and without bovine dentin discs (200 mum and 500 mum thickness) placed between bacteria and test substances. The effect of 0.3% triclosan on all tester strains (100%) was reduced after passage through 500 mum dentin discs to 0% (L. acidophilus) and to 22% and 28% (S. mutans and S. sobrinus). Seal&Protect (Dentsply, Konstanz, Germany), a triclosan containing dental bonding agent, produced inhibition zones only against S. mutans, but no zone when applied on 200 mum dentin discs. The inhibition zones for 1% NaOCl and 5% glutaraldehyde against all tester strains were significantly increased up to 230% (glutaraldehyde) and 236% (NaOCl) when applied on dentin discs, compared to direct application (100%). Dentin may either decrease or increase the inhibitory effect of antibacterial agents.
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Affiliation(s)
- Zeynep Ergücü
- Department of Operative Dentistry and Periodontology, University of Regensburg, Regensburg, Germany
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111
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Schäfer E, Bössmann K. Antimicrobial Efficacy of Chlorhexidine and Two Calcium Hydroxide Formulations Against Enterococcus faecalis. J Endod 2005; 31:53-6. [PMID: 15614008 DOI: 10.1097/01.don.0000134209.28874.1c] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The purpose of this study was to investigate the efficacy of chlorhexidine (CHX) and calcium hydroxide (Ca(OH2) against Enterococcus faecalis in vitro. Extracted single-rooted human teeth were instrumented up to size 40. After removal of the smear layer, an inoculum of E. faecalis was inserted into the root canals. After incubation, the inoculum was removed and the root canals were filled with one of three different disinfectants: Ca(OH2 paste, CHX 2%, and a mixture of CHX and Ca(OH2 paste (n = 10 in each group). Control teeth were filled with water of standardized hardness (n = 10). The teeth were then incubated for 3 days. After incubation, each root canal was instrumented, and the removed dentin was examined microbiologically. CHX was significantly more effective against E. faecalis than was Ca(OH2 paste or a mixture of CHX with Ca(OH2 paste (p < 0.05). There was no increase in the efficiency of Ca(OH2 paste when CHX was added (p > 0.05). The results suggest that CHX is effective in the elimination of E. faecalis from dentinal tubules under the conditions of this study.
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Affiliation(s)
- Edgar Schäfer
- Poliklinik für Zahnerhaltung, University School of Dentistry, Münster, Germany.
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112
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Basrani B, Ghanem A, Tjäderhane L. Physical and chemical properties of chlorhexidine and calcium hydroxide-containing medications. J Endod 2004; 30:413-7. [PMID: 15167469 DOI: 10.1097/00004770-200406000-00009] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
This study was performed to evaluate the physicochemical properties (pH, contact angle, working time, radio-opacity, and viscosity) of chlorhexidine (CHX) and calcium hydroxide-containing medications in gel form in different concentrations. The pH value was assessed with a pH meter. The contact angle was measured with a goniometer. The radio-opacity and working time measurements were taken in accordance with the standards of the International Organization for Standardization. The viscosity was evaluated using a Brookfield RVDV viscometer. The results showed that CHX did not affect the pH, radio-opacity, and working time of the calcium hydroxide-containing medications (p < 0.05). However, adding CHX lowered the contact angle and increased the viscosity of calcium hydroxide significantly. This research showed that CHX in different concentrations and in combination with calcium hydroxide has satisfactory physicochemical properties to be used as an intracanal medication.
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Affiliation(s)
- Bettina Basrani
- Division of Endodontics, Department of Dental Clinical Sciences, Dalhousie University, 5981 University Avenue #5176, Halifax, Nova Scotia, Canada B3H 3J5.
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113
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Radcliffe CE, Potouridou L, Qureshi R, Habahbeh N, Qualtrough A, Worthington H, Drucker DB. Antimicrobial activity of varying concentrations of sodium hypochlorite on the endodontic microorganisms Actinomyces israelii, A. naeslundii, Candida albicans and Enterococcus faecalis. Int Endod J 2004; 37:438-46. [PMID: 15189432 DOI: 10.1111/j.1365-2591.2004.00752.x] [Citation(s) in RCA: 142] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
AIM To determine the resistance of microorganisms associated with refractory endodontic infections to sodium hypochlorite used as a root canal irrigant. METHODOLOGY Two strains each of Actinomyces naeslundii, Candida albicans and Enterococcus faecalis were tested as late logarithmic phase inocula, against sodium hypochlorite adjusted to 0.5, 1.0, 2.5 and 5.25% w/v. Contact times used were 0, 10, 20, 30, 60 and 120 s. In the case of E. faecalis, additional experiments used contact times of 1.0, 2.0, 5.0, 10.0 and 30.0 min. Anti-microbial action was halted by sodium thiosulphate addition. Survivors were measured primarily using viable counts on drop plates. Additionally, pour plates were used to count low colony-forming units (cfu) and dilutions to 10(-6) were used to count high cfu. RESULTS All concentrations of NaOCl lowered cfu below the limit of detection after 10 s in the case of A. naeslundii and C. albicans. However, E. faecalis proved to be more resistant to NaOCl. Using 0.5% NaOCl for 30 min reduced cfu to zero for both strains tested. This compares with 10 min for 1.0%, 5 min for 2.5% and 2 min for 5.25% (P < 0.001). Regression analysis for the dependent variable log(e)(count + 1) with log(e)(time + 1) and concentration as explanatory variables gave rise to a significant interaction between time and concentration (P < 0.001). CONCLUSION The published association of E. faecalis with refractory endodontic infection may result, at least partially, from high resistance of this species to NaOCl. This does not appear to be the case with A. naeslundii or C. albicans.
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Affiliation(s)
- C E Radcliffe
- Oral Microbiology Laboratory, University Dental Hospital of Manchester, Manchester, UK
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114
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Barroso LDS, Habitante SM, Jorge AOC, Faria IDS. Microorganisms growth in endodontic citric-acid solutions with and without microbiological stabilizer. J Endod 2004; 30:42-4. [PMID: 14760907 DOI: 10.1097/00004770-200401000-00009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The purpose of this study was to determine if citric-acid solutions for endodontic use can become contaminated and if the addition of a microbiological stabilizer to the acid would modify this situation. Five types of microorganisms were inoculated in tubes containing 10% citric-acid solutions, pH 1.8 (group A1), and 10% solution, pH 1.8, combined with 0.1% sodium benzoate (group A2). The results demonstrated that solutions of group A1 were contaminated with Candida albicans in 100% of the tubes, Escherichia coli in 80%, and Enterococcus faecalis in 50%. When stabilizer was added (group A2), C. albicans grew in only 30% of tubes and all bacterial species were neutralized.
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115
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Basrani B, Tjäderhane L, Santos JM, Pascon E, Grad H, Lawrence HP, Friedman S. Efficacy of chlorhexidine- and calcium hydroxide-containing medicaments against Enterococcus faecalis in vitro. ACTA ACUST UNITED AC 2004; 96:618-24. [PMID: 14600699 DOI: 10.1016/s1079-2104(03)00166-5] [Citation(s) in RCA: 88] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
OBJECTIVE We sought to assess the efficacy of chlorhexidine (CHX) and calcium hydroxide, Ca(OH)(2), against Enterococcus faecalis in vitro. STUDY DESIGN The effect of CHX (0.2% and 2% in gel or solution) and Ca(OH)(2) (alone or with 0.2% CHX gel) was evaluated by using the agar diffusion test and an in vitro human root inoculation method, to measure zone of inhibition or bacterial growth with optical density analysis, respectively. For optical density analysis, samples from infected root canals were collected after 7 days of medication and were cultured for 24 hours in brain-heart infusion to detect viable bacteria. RESULTS In the agar diffusion test, CHX was effective against E faecalis in a concentration-dependent fashion, but Ca(OH)(2) alone had no effect. In the root canal inoculation test, CHX was significantly more effective against E faecalis than Ca(OH)(2) was (P < .05), but there were no significant differences between the modes of medication or concentrations of CHX. CONCLUSIONS CHX is effective against E faecalis in vitro. Further in vivo studies are needed to confirm the value of CHX in clinical treatment.
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Affiliation(s)
- Bettina Basrani
- Dalhousie University, Endodonic Division, Department of Dental Clinical Sciences, Halifax, Nova Scotia, Canada.
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116
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Vianna ME, Gomes BPFA, Berber VB, Zaia AA, Ferraz CCR, de Souza-Filho FJ. In vitro evaluation of the antimicrobial activity of chlorhexidine and sodium hypochlorite. ACTA ACUST UNITED AC 2004; 97:79-84. [PMID: 14716261 DOI: 10.1016/s1079-2104(03)00360-3] [Citation(s) in RCA: 190] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The aim of this study was to investigate in vitro the antimicrobial activity of 0.2%, 1%, and 2% chlorhexidine gluconate (CHX gel and CHX liquid), against endodontic pathogens and compare the results with the ones achieved by 0.5%, 1%, 2.5%, 4%, and 5.25% sodium hypochlorite (NaOCl). A broth dilution test was performed, and the timing for irrigants to kill microbial cells was recorded and statistically analyzed. Both 2.0% gel and liquid formulations eliminated Staphylococcus aureus and Candida albicans in 15 seconds, whereas the gel formulation killed Enterococcus faecalis in 1 minute. All tested irrigants eliminated Porphyromonas endodontalis, Porphyromonas gingivalis, and Prevotella intermedia in 15 seconds. The timing required for 1.0% and 2.0% CHX liquid to eliminate all microorganisms was the same required for 5.25% NaOCl. The antimicrobial action is related to type, concentration, and presentation form of the irrigants as well as the microbial susceptibility.
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Affiliation(s)
- Morgana Eli Vianna
- Department of Restorative Dentistry, Piracicaba Dental School, State University of Campinas, SP, Brazil
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117
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Sassone LM, Fidel R, Fidel S, Vieira M, Hirata R. The influence of organic load on the antimicrobial activity of different concentrations of NaOCl and chlorhexidine in vitro. Int Endod J 2003; 36:848-52. [PMID: 14641423 DOI: 10.1111/j.1365-2591.2003.00724.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
AIM To evaluate bacterial growth after contact with sodium hypochlorite (NaOCl; 1 and 5%) and chlorhexidine (CHX; 0.12, 0.5 and 1%) in vitro with or without the addition of organic material (bovine serum albumin (BSA) 0.5%). METHODOLOGY Bacterial samples (American Type Culture Collection (ATCC)) of Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Porphyromonas gingivalis and Fusobacterium nucleatum were kept in contact with each irrigating solution for varying intervals of time: immediately (t0), 5 min (t5), 15 min (t15) and 30 min (t30). Each test was repeated 10 times. In half of the specimens, 0.5% BSA was added as organic material in an attempt to simulate the organic tissue present in the root canal system. Bacterial growth under appropriate condition of incubation was evaluated and compared for each microorganism at all time intervals. RESULTS A 0.12% CHX solution did not eliminate E. faecalis at any time interval. One percent CHX eliminated all strains, as did both NaOCl concentrations. BSA did not interfere substantially with the antimicrobial activity of any of the irrigating solutions. CONCLUSIONS Under the condition of this study, a 0.12% CHX solution was ineffective at killing E. faecalis.
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Affiliation(s)
- L M Sassone
- Proclin Department, School of Dentistry, Rio de Janeiro State University, Rio de Janeiro, Brazil.
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118
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Sassone LM, Fidel RAS, Fidel SR, Dias M, Hirata RJ. Antimicrobial activity of different concentrations of NaOCl and chlorhexidine using a contact test. Braz Dent J 2003; 14:99-102. [PMID: 12964652 DOI: 10.1590/s0103-64402003000200005] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The purpose of this study was to analyze the in vitro antimicrobial activity of sodium hypochlorite (1% and 5%) and chlorhexidine (0.12%, 0.5% and 1%). Bacterial samples (ATCC) of Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Porphyromonas gingivalis and Fusobacterium nucleatum were submitted to a contact test. Solutions were evaluated at different time intervals: immediately, 5 min, 15 min, and 30 min after contact and repeated 10 times. The results of the contact test showed that 0.12% chlorhexidine did not eliminate E. faecalis at any time interval, while 0.5% and 1% chlorhexidine and 1% and 5% sodium hypochlorite did. These results permit us to conclude that to obtain better antimicrobial activity, chlorhexidine in a concentration greater than 0.12% should be used.
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Affiliation(s)
- Luciana Moura Sassone
- Faculty of Dentistry, State University of Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
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119
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Siqueira JF, Rôças IN, Lopes HP, Magalhães FAC, de Uzeda M. Elimination of Candida albicans infection of the radicular dentin by intracanal medications. J Endod 2003; 29:501-4. [PMID: 12929695 DOI: 10.1097/00004770-200308000-00003] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Fungi have been associated with cases of secondary or persistent root canal infections. The purpose of this study was to evaluate the effectiveness of four intracanal medications in disinfecting the root dentin of bovine teeth experimentally infected with Candida albicans. Infected dentin cylinders were exposed to four different medications: calcium hydroxide/glycerin; calcium hydroxide/0.12% chlorhexidine digluconate; calcium hydroxide/camphorated paramonochlorophenol/glycerin; and 0.12% chlorhexidine digluconate/zinc oxide. Specimens were in contact with the medications for 1 h, 2 days, and 7 days. The viability of C. albicans after exposure was evaluated by specimen incubation in culture medium to compare the effectiveness of the medications in disinfecting dentin. Results showed that the specimens treated with calcium hydroxide/camphorated paramonochlorophenol/ glycerin paste or with chlorhexidine/zinc oxide paste were completely disinfected after 1 h of exposure. Calcium hydroxide/glycerin paste only consistently eliminated C. albicans infection after 7 days of exposure. Calcium hydroxide mixed with chlorhexidine was ineffective in disinfecting dentin even after 1 week of medication exposure. Among the medications tested, the calcium hydroxide/camphorated paramonochlorophenol/glycerin paste and chlorhexidine digluconate mixed with zinc oxide were the most effective in eliminating C. albicans cells from dentinal specimens.
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Affiliation(s)
- José F Siqueira
- Department of Endodontics, Estácio de Sá University, Rio de Janeiro, RJ, Brazil
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120
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Abstract
The purpose of this paper is to provide useful information that will enable dentists to predictably shape root canals for three-dimensional obturation of the root canal system. The information is intended to help clinicians better understand when and how to safely use Nickel-Titanium (NiTi) rotary shaping instruments. This article is intended to enhance clinical performance for all dentists who perform root canal preparation procedures regardless of which instruments are chosen and the techniques employed during their utilisation. The guidelines for successful access and the concepts and strategies for canal preparation are discussed. Additionally, the advantages of negotiating and then pre-enlarging the coronal two-thirds of the canal before negotiating and finishing the apical one-third are emphasised. Although a set of endodontic instruments can shape a root canal, this article will also review the importance of irrigants and their role in cleaning the root canal system.
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121
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Estrela C, Ribeiro RG, Estrela CRA, Pécora JD, Sousa-Neto MD. Antimicrobial effect of 2% sodium hypochlorite and 2% chlorhexidine tested by different methods. Braz Dent J 2003; 14:58-62. [PMID: 12656467 DOI: 10.1590/s0103-64402003000100011] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The objective of this study was to analyze the antimicrobial effect of 2% sodium hypochlorite (NaOCl) and 2% chlorhexidine (CHX) by agar diffusion test and by direct exposure test. Five microorganisms: Staphylococcus aureus, Enterococcus faecalis, Pseudomonas aernginosa, Bacillus subtilis, Candida albicans, and one mixture of these were used. These strains were inoculated in brain heart infusion (BHI) and incubated at 37 degrees C for 24 h. For the agar diffusion test (ADT), 18 Petri plates with 20 ml of BHI agar were inoculated with 0.1 ml of the microbial suspensions, using sterile swabs that were spread on the medium, obtaining growth injunction. Fifty-four paper disks (9 mm in diameter) were immersed in the experimental solutions for 1 min. Subsequently, three papers disks containing one of the substances were placed on the BHI agar surface in each agar plate. The plates were maintained for 1 h at room temperature, and then incubated at 37 degrees C for 48 h. The diameter of microbial inhibition was measured around the papers disks containing the substances. For the direct exposure test, 162#50 sterile absorbent paper points were immersed in the experimental suspensions for 5 min, and were then placed on Petri plates and covered with one of the irrigant solutions, or with sterile distilled water (control group). After intervals of 5, 1 0 and 30 min, the paper points were removed from contact with the solutions and individually immersed in 7 ml of Letheen Broth, followed by incubation at 37 degrees C for 48 h. Microbial growth was evaluated by turbidity of the culture medium. A 0.1 ml inoculum obtained from the Letheen Broth was transferred to 7 ml of BHI, and incubated at 37 degrees C for 48 h. Bacterial growth was again evaluated by turbidity of the culture medium. Gram stain of BHI cultures was used for verification of contamination and growth was determined by macroscopic and microscopic examination. The best performance of antimicrobial effectiveness of NaOCI was observed in the direct exposure test, and of CHX was observed in the agar diffusion test. The magnitude of antimicrobial effect was influenced by the experimental methods, biological indicators and exposure time.
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Affiliation(s)
- Carlos Estrela
- Faculty of Dentistry, Federal University of Goiás, Goiânia, GO, Brazil.
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122
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Grawehr M, Sener B, Waltimo T, Zehnder M. Interactions of ethylenediamine tetraacetic acid with sodium hypochlorite in aqueous solutions. Int Endod J 2003; 36:411-7. [PMID: 12801288 DOI: 10.1046/j.1365-2591.2003.00670.x] [Citation(s) in RCA: 114] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
AIM To evaluate interactions of ethylenediamine tetraacetic acid (EDTA) with sodium hypochlorite (NaOCl). METHODOLOGY Solutions consisting of 8.5% EDTA and 0.5% NaOCl were compared to a 1 : 1 (w/w) mixture of 17% EDTA and 1% NaOCl for their calcium-chelating, tissue-dissolving, and antimicrobial properties. Amounts of available chlorine were determined in the EDTA/NaOCl solutions with an iodine/thiosulphate titration method. Calcium chelation capacity was titrated with a pure calcium solution using a murexide indicator. Weight loss of porcine palatal mucosal specimens incubated in the test solutions was measured over time. Antimicrobial potential of pure solutions and the combination was recorded using an agar diffusion test in plates incubated with Enterococcus faecalis or Candida albicans. RESULTS The presence of hypochlorite had little effect on the calcium-chelating ability or on the antimicrobial potential of EDTA. Available chlorine content decreased to 0.06% in the combined EDTA-NaOCl solution compared to 0.50% in an equivalent NaOCl mixture with deionized water. The EDTA-NaOCl solution did not dissolve more tissue than an equivalent pure EDTA solution at any time (anova, P > 0.05). CONCLUSIONS Ethylenediamine tetraacetic acid retained its calcium-complexing ability when mixed with NaOCl, but EDTA caused NaOCl to lose its tissue-dissolving capacity and virtually no free chlorine was detected in the combinations. Clinically, this suggests that EDTA and NaOCl should be used separately. In an alternating irrigating regimen, copious amounts of NaOCl should be administered to wash out remnants of the EDTA.
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Affiliation(s)
- M Grawehr
- Department of Preventive Dentistry, Cariology, and Periodontology, University of Zürich Center for Dental Medicine, Zürich, Switzerland
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123
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Marchesan MA, Arruda MPD, Silva-Sousa YTC, Saquy PC, Pecora JD, Sousa-Neto MD. Morphometrical analysis of cleaning capacity using nickel-titanium rotary instrumentation associated with irrigating solutions in mesio-distal flattened root canals. J Appl Oral Sci 2003; 11:55-9. [DOI: 10.1590/s1678-77572003000100010] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Variations in the internal anatomy of root canals may interfere with the success of root canal because tissue remnants may remain in the isthmus, re-entrances and ramifications of flattened root canals making instrumentation more difficult. Successful root canal treatment depends fundamentally on shaping, cleaning, disinfection and obturation. This study verified the quality of cleaning of ProFile .04 rotary technique associated with different irrigating solutions: 0.5% sodium hypochlorite, calcium hydroxide + Tergentol and 2% chlorhexidine in canals with mesio-distal flattening. Twelve human mandibular central incisors were randomly divided into 3 groups and instrumented up to ProFile 0.4 #35 file after cervical preparation, and processed histologically. After optical microscopic evaluation, statistical analysis showed that the percentage of cleaning of the three irrigating solutions was statistically different. Two-by-two comparisons classified the irrigating solutions in increasing order of cleaning: calcium hydroxide + Tergentol < chlorhexidine < 0.5% sodium hypochlorite.
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124
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Estrela CRA, Estrela C, Reis C, Bammann LL, Pécora JD. Control of microorganisms in vitro by endodontic irrigants. Braz Dent J 2003; 14:187-92. [PMID: 15057395 DOI: 10.1590/s0103-64402003000300009] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The aim of this study was to determine the minimum inhibitory concentration (MIC) and antimicrobial effectiveness by the direct exposure test of 4 endodontic irrigants [1% sodium hypochlorite (NaOCl), 2% chlorhexidine (CHX), 1% calcium hydroxide (Ca(OH)2; prepared with 1 g of Ca(OH)2 and 100 mL of sterile distilled water), a solution of Ca(OH)2 + detergent (HCT20)] for S. aureus, E. faecalis, P. aeruginosa, B. subtilis, C. albicans and a mixed culture. Microbial growth was analyzed by two methods: turbidity of the culture medium that was confirmed by Gram stain and subculture in a specific nutrient broth. In the dilution test, NaOCl solution showed MIC equal to 0.1% for S. aureus, E. faecalis, P. aeruginosa and C. albicans and equal to 1% for B. subtilis and the mixed culture. CHX (2%) presented MIC equal to 0.000002% for S. aureus, 0.02% for E. faecalis, B. subtilis, C. albicans and the mixed culture and 0.002% for P. aeruginosa. Ca(OH)2 solution (1%) showed MIC greater than 1% for all the microorganisms except P. aeruginosa for which it was equal to 1%. Calcium hydroxide solution + detergent showed MIC equal to 4.5 mL for S. aureus, P. aeruginosa, B. subtilis, C. albicans and the mixed culture and greater than 4.5 mL for E. faecalis. In the direct exposure test, NaOCl had better antimicrobial effectiveness for all microorganisms at all times. CHX (2%) was effective for S. aureus, E. faecalis and C. albicans at all times, and ineffective for P. aeruginosa, B. subtilis and the mixed culture. The other solutions showed the worst results.
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125
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Basrani B, Santos JM, Tjäderhane L, Grad H, Gorduysus O, Huang J, Lawrence HP, Friedman S. Substantive antimicrobial activity in chlorhexidine-treated human root dentin. ORAL SURGERY, ORAL MEDICINE, ORAL PATHOLOGY, ORAL RADIOLOGY, AND ENDODONTICS 2002; 94:240-5. [PMID: 12221393 DOI: 10.1067/moe.2002.124002] [Citation(s) in RCA: 117] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
OBJECTIVE The aim of this in vitro study was to assess the substantive antimicrobial activity of different medicaments in human root dentin. STUDY DESIGN Canals of 98 roots were enlarged to standard size and medicated for 7 days with the following: (1) 2% chlorhexidine (CHX) gel, (2) 0.2% CHX gel, (3) 2% CHX solution, (4) Ca(OH)(2), (5) Ca(OH)(2)+ 0.2% CHX gel, (6) 2% CHX solution + a 25% CHX-containing controlled-release device, (7) saline, and (8) gel vehicle. After medication, canals were inoculated with Enterococcus faecalis for 21 days. Dentin samples were collected with Gates-Glidden burs into brain heart infusion broth, and bacterial growth was assessed with spectrophotometric analysis of optical density after 72 hours of incubation. RESULTS Mean optical densities were significantly lower for groups with 2% CHX (1, 3, and 6) when compared with those of the controls (P < .05, analysis of variance with the Tukey test). Other groups did not differ significantly from the controls. CONCLUSIONS Canal dressing for 1 week with 2% CHX may provide residual antimicrobial activity against E faecalis.
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Affiliation(s)
- Bettina Basrani
- Department of Endodontics, Faculty of Dentistry, University of Toronto, Ontario, Canada.
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126
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Siqueira JF, Rôças IN, Santos SRLD, Lima KC, Magalhães FAC, de Uzeda M. Efficacy of instrumentation techniques and irrigation regimens in reducing the bacterial population within root canals. J Endod 2002; 28:181-4. [PMID: 12017176 DOI: 10.1097/00004770-200203000-00009] [Citation(s) in RCA: 114] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
The purpose of this study was to compare the in vitro intracanal bacterial reduction produced by using two instrumentation techniques and different irrigation methods. Root canals inoculated with Enterococcus faecalis were prepared by using the following techniques and irrigants: alternated rotary motions (ARM) technique, hand nickel-titanium files and 2.5% sodium hypochlorite (NaOCl) as irrigant; ARM technique and combined irrigation with 2.5% NaOCl and citric acid; ARM technique and combined irrigation with 2.5% NaOCl and 2% chlorhexidine gluconate; and Greater Taper rotary files, using 2.5% NaOCl as irrigant. Controls were instrumented by using the ARM technique and irrigated with sterile saline. Canals were sampled before and after preparation. After serial dilution, samples were plated onto Mitis-Salivarius agar, and the colony forming units that were grown were counted. All test techniques and solutions significantly reduced the number of bacterial cells within the root canal (p < 0.05). There was no significant difference between the experimental groups (p > 0.05). Nonetheless, all of them were significantly more effective than the control group (p < 0.05). These findings support the importance of using antimicrobial irrigants during the chemomechanical preparation, regardless of the solutions or instrumentation techniques used.
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Affiliation(s)
- José F Siqueira
- Oral Microbiology Laboratory, Institute of Microbiology, Federal University of Rio de Janeiro, RJ, Brazil
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127
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Lima KC, Fava LR, Siqueira JF. Susceptibilities of Enterococcus faecalis biofilms to some antimicrobial medications. J Endod 2001; 27:616-9. [PMID: 11592490 DOI: 10.1097/00004770-200110000-00004] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Enterococcus faecalis has been suggested to be an important etiological agent in endodontic failures. The purpose of this study was to evaluate the effectiveness of chlorhexidine- or antibiotics-based medications in eliminating E. faecalis biofilms. One-day and three-day biofilms of E. faecalis were induced on cellulose nitrate membrane filters. Each biofilm-containing membrane was thoroughly covered with 1 ml of the test medications and incubated for 1 day at 37 degrees C. Treated biofilms were then aseptically transferred to vials containing a neutralizing agent in saline solution and vortexed. Suspensions were 10-fold diluted, seeded onto Mitis salivarius agar plates, and the colony-forming units counted after 48 h of incubation. There were significant differences between the formulations tested. The association of clindamycin with metronidazole significantly reduced the number of cells in 1-day biofilms. However of all medications tested, only 2% chlorhexidine-containing medications were able to thoroughly eliminate most of both 1-day and 3-day E. faecalis biofilms.
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Affiliation(s)
- K C Lima
- Department of Preventive and Social Dentistry, Faculty of Dentistry, Federal University of Rio Grande do Norte, Natal, Brazil
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128
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Gomes BP, Ferraz CC, Vianna ME, Berber VB, Teixeira FB, Souza-Filho FJ. In vitro antimicrobial activity of several concentrations of sodium hypochlorite and chlorhexidine gluconate in the elimination of Enterococcus faecalis. Int Endod J 2001; 34:424-8. [PMID: 11556507 DOI: 10.1046/j.1365-2591.2001.00410.x] [Citation(s) in RCA: 287] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
AIM The aim of this study was to assess, in vitro, the effectiveness of several concentrations of NaOCl (0.5%, 1%, 2.5%, 4% and 5.25%) and two forms of chlorhexidine gluconate (gel and liquid) in three concentrations (0.2%, 1% and 2%) in the elimination of E. faecalis. METHODOLOGY A broth dilution test using 24-well cell culture plates was performed and the time taken for the irrigants to kill bacterial cells was recorded. Isolated 24 h colonies of pure cultures of E. faecalis grown on 10% sheep blood plus Brain Heart Infusion (BHI) agar plates were suspended in sterile 0.85% NaCI solution. The cell suspension was adjusted spectrophotometrically to match the turbidity of a McFarland 0.5 scale. One mL of each tested substance was placed on the bottom of wells of 24-well cell culture plates (Corning, NY), including the control group (sterile saline). Six wells were used for each time period and irrigant concentration. Two mL of the bacterial suspension were ultrasonically mixed for 10 s with the irrigants and placed in contact with them for 10, 30, and 45 s; 1, 3, 5, 10, 20, and 30 min; and 1 and 2 h. After each period of time, 1 mL from each well was transferred to tubes containing 2 mL of freshly prepared BHI + neutralizers in order to prevent a residual action of the irrigants. All tubes were incubated at 37 degrees C for 7 days. The tubes considered to have positive growth were those which presented medium turbidity during the incubation period. Data were analysed statistically by the Kruskal-Wallis test. with the level of significance set at P < 0.05. RESULTS All irrigants were effective in killing E. faecalis. but at different times. Chlorhexidine in the liquid form at all concentrations tested (0.2%, 1% and 2%) and NaOCI (5.25%) were the most effective irrigants. However, the time required by 0.2% chlorhexidine liquid and 2% chlorhexidine gel to promote negative cultures was only 30 s and 1 min, respectively. CONCLUSIONS Even though all tested irrigants possessed antibacterial activity, the time required to eliminate E. faecalis depended on the concentration and type of irrigant used.
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Affiliation(s)
- B P Gomes
- Endodontic Unit, School of Dentistry of Piracicaba, State University of Campinas-UNICAMP, SP, Brazil.
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129
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Spratt DA, Pratten J, Wilson M, Gulabivala K. An in vitro evaluation of the antimicrobial efficacy of irrigants on biofilms of root canal isolates. Int Endod J 2001; 34:300-7. [PMID: 11482142 DOI: 10.1046/j.1365-2591.2001.00392.x] [Citation(s) in RCA: 129] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
AIM The bactericidal effect of four antimicrobial agents was investigated against single-species biofilms derived from a range of root canal isolates. METHODOLOGY Single-species biofilms of Prevotella intermedia, Peptostreptococcus micros, Streptococcus intermedius, Fusobacterium nucleatum and Enterococcus faecalis were generated on membrane filter discs and subjected to 15 min or 1 h incubation with 5 p.p.m. colloidal silver, 2.25% sodium hypochlorite (NaOCl), 0.2% chlorhexidine, 10% iodine or phosphate buffered saline (PBS) as a control. The antimicrobial activity of the agents was neutralized and the bacterial cells were harvested from the discs by vortexing, serially diluted in reduced transport fluid, plated on fastidious anaerobe agar containing 5% horse blood, incubated anaerobically and colony-forming units calculated. RESULTS Iodine and NaOCl were more effective than chlorhexidine except against P. micros and P. intermedia where they were all 100% effective. Iodine and NaOCl elicited a 100% kill after 1 h incubation for all strains used. However, after 15 min, they showed differing bactericidal effects depending on the strain. None of the agents were effective against F. nucleatum after 15 min but NaOCl, iodine and chlorhexidine were all effective after 1 h. Colloidal silver was generally ineffective. CONCLUSIONS The effectiveness of a particular agent was dependent on the nature of the organism in the biofilm and on the contact time. NaOCl was generally the most effective agent tested, followed by iodine. However the clinical efficacy of these agents must be considered in light of the complex root canal anatomy and polymicrobial nature of root canal infections.
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Affiliation(s)
- D A Spratt
- Department of Conservative Dentistry, Eastman Dental Institute for Oral Health Care Sciences, University College London, University of London, London, UK.
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130
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Abstract
The purpose of this study was to compare three methods of evaluation of the apical seal. Thirty-six teeth were prepared with a ProFile device and filled according to three filling methods: Thermafil (n = 12), warm vertical condensation (n = 12), and the single cone technique (n = 2). The apical seal was recorded with three methods, each successively used on the same teeth: a fluid filtration method, an electrochemical method, and a dye penetration study. The three methods of evaluation did not rank the apical leakage of the three filling techniques in the same order. The fluid filtration method showed that the vertical condensation was superior to Thermafil, which was in turn superior to the single cone technique (p = 0.04). The dye penetration study showed that the Thermafil was a better technique than the vertical condensation and the single cone technique (p = 0.005). The electrochemical method showed no statistical difference among the three filling techniques. No correlation was found among the results obtained with the three methods of evaluation. This study shows that several studies are necessary before comparing the apical seal obtained with various filling techniques.
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Affiliation(s)
- L Pommel
- Unité IMEB, Faculté d'Odontologie, Marseille, France
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131
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Heling I, Rotstein I, Dinur T, Szwec-Levine Y, Steinberg D. Bactericidal and cytotoxic effects of sodium hypochlorite and sodium dichloroisocyanurate solutions in vitro. J Endod 2001; 27:278-80. [PMID: 11485267 DOI: 10.1097/00004770-200104000-00009] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The antimicrobial and cytotoxic effects of sodium hypochlorite (NaOCl) and sodium dichloroisocyanurate (NaDCC) were evaluated and compared in vitro. The minimal inhibitory concentration and minimal bactericidal concentration of NaOCl and NaDCC were tested for Streptococcus sobrinus, Streptococcus salivarius, Enterococcus faecalis, and Streptococcus mutans. The cytotoxic effect was assessed by using human fibroblast tissue culture. Survival rate was assessed by a protein determination method. Results showed that the minimal inhibitory concentration and minimal bactericidal concentration values of NaOCl and NaDCC for the tested bacteria were in a similar range. NaDCC in concentrations higher than 0.02%, and NaOCl in concentrations higher than 0.01% were lethal to fibroblasts. In conclusion it seems that both agents were very effective in killing bacteria, and their cytotoxicity to fibroblasts in tissue culture was similar.
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Affiliation(s)
- I Heling
- Department of Endodontics, The Hebrew University-Hadassah, Faculty of Dental Medicine, Jerusalem, Israel
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132
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Abstract
AIM A new product, electro-chemically activated water, was compared to NaOCl for its cleaning effect on root canal walls. METHODOLOGY Root canal treatment was carried out on two groups of extracted teeth with one of the irrigants being used in each group. The control group received no treatment. All teeth were split and the canal walls viewed in a scanning electron microscope. RESULTS The canal walls of the control group were covered by debris and bacteria. Sodium hypochlorite produced clean surfaces with the dentinal tubules open in some areas and occluded by the smear layer in other areas; in some areas bacteria were visible inside or under the smear layer. Electro-chemically activated water produced markedly cleaner surfaces, removing the smear layer in large areas. CONCLUSIONS The cleaning efficacy of electro-chemically activated water in root canals was considered to be superior to NaOCl.
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Affiliation(s)
- J T Marais
- Department of Restorative Dentistry, Faculty of Dentistry, University of Pretoria, Pretoria, Republic of South Africa.
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133
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Abstract
The aims of this study were to find a dentin bonding system suitable for root canal treatment using a newly developed root canal resin sealer, and to examine its sealing ability. The sealer was composed of vinylidene fluoride/hexafluoropropylene copolymer, methyl methacrylate, zirconia, and tributylborane catalyst. The effects of dentin conditioners and primers on dentin bonding were studied by tensile bond strength testing and scanning electron microscopy. Apical and coronal leakage were evaluated at 1-, 4-, and 12-wk intervals by a dye penetration test using a methylene blue solution. Pulp Canal Sealer EWT and Sealapex were used as controls. Significantly high bond strength was obtained by treating dentin with EDTA, followed by application of a glutaraldehyde/2-hydroxyethyl methacrylate primer. The experimental resin sealer produced a significantly superior coronal seal at 12 wk when compared with the two control sealers (p < 0.05). Scanning electron microscopic examination revealed few gaps at the resin sealer-dentin interface.
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Affiliation(s)
- H Kataoka
- Department of Endodontics, Faculty of Dentistry, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo 113-8549, Japan
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