Postoperative pain following the use of two different intracanal medications

This study evaluated the incidence of postoperative pain after intracanal dressings with either 0.12% chlorhexidine digluconate gel (CHX) or a calcium hydroxide/camphorated paramonochlorophenol/glycerin paste (CH/CPMC). Overall, 138 asymptomatic teeth had their canals instrumented under irrigation with 2.5% NaOCl and then dressed with either CH/CPMC or CHX. The incidence of different intensity levels of postoperative pain was registered for the period between appointments. Data revealed that 84% of the total number of cases treated with either medicament showed absence of any level of pain. No case medicated with CH/CPMC and four cases (5.8%) medicated with CHX were categorized as flare-ups. There were no statistically significant differences between all possible comparisons involving the two medicaments in treatment/retreatment cases and teeth with/without apical periodontitis lesions. The low incidence of postoperative pain after the use of both medications, coupled to their antimicrobial effectiveness, gives support to using one or the other in routine treatment/retreatment.     

ANTIMICROBIAL ACTIVITY OF SODIUM HYPOCHLORITE ASSOCIATED WITH INTRACANAL MEDICATION FOR Candida albicans AND Enterococcus faecalis INOCULATED IN ROOT CANALS

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.     

Antimicrobial potential of medicaments used in healing process in dogs' teeth with apical periodontitis

The objective of this study was to evaluate the influence of irrigants on the antimicrobial potential of calcium hydroxide paste in dogs' teeth with apical periodontitis. Forty-eight premolar teeth of adult mongrel dogs had their root canals opened to the oral environment for 6 months. The root canals were prepared and treated with different irrigating solutions and intracanal medicaments, according to the following groups: 1) 2.5% sodium hypochlorite (NaOCl) + calcium hydroxide paste (CHP); 2) 2% chlorhexidine (CHX) + CHP; 3) vinegar + CHP; 4) vinegar + vinegar. In group 4, both the irrigating solution and intracanal medicament were vinegar, which was renewed every 7 days. Each sample was collected by using two paper points maintained in position for 1 min, and individually transported and immersed in 7 mL of Letheen broth (LB), followed by incubation at 37 masculineC for 48 h. Microbial growth was analyzed by two methods: turbidity of the culture medium and subculture on a specific nutrient broth (brain heart infusion). After 21 days, all experimental groups had microbial growth, however, in different percentages: group 1 - 30%; group 2 - 30%; group 3 - 40%; group 4 - 60%. All materials tested had antimicrobial potential; however, the influence of calcium hydroxide paste on the control of microorganisms must be remembered.     

Antimicrobial Effect of Conventional Root Canal Medicaments vs Propolis against Enterococcus faecalis, Staphylococcus aureus and Candida albicans

Aim: To evaluate and compare antimicrobial effect of various root canal medicaments against Enterococcus faecalis, Staphylococcus aureus and Candida albicans. Materials and methods: Six root canal medicaments: 2% sodium hypochlorite (NaOCl), 2% chlorhexidine (CHX) Calcium hydroxide (Ca(OH)2), EDTA, MTAD and propolis and three microorganisms: Staphylococcus aureus, Enterococcus faecalis and Candida albicans were used. These strains were inoculated in brain heart infusion (BHI) and incubated at 37 degrees C for 24 hours. For the agar diffusion test (ADT), 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. Paper disks were immersed in the experimental solutions for 1 minute. Subsequently, four papers disks containing one of the substances were placed on the BHI agar surface in each agar plate. The plates were incubated at 37°C for 48 hours. The diameter of microbial inhibition was measured around the papers disks containing the substances. One way ANOVA followed by Tukey's post-hoc test were used. p-value >0.05 was considered statistically significant. Results: Propolis and other irrigants were found to be effective on C. albicans, S. aureus and E. faecalis. CHX and MTAD were found to be most effective amongst all the materials tested followed by propolis. Conclusion: Propolis showed antimicrobial activity against E. faecalis, S. aureus, C. albicans. It appears that propolis is an effective intracanal irrigant in eradicating E. faecalis and C. albicans. Clinical significance: Propolis is an effective intracanal irrigant in eradicating E. faecalis and C. albicans. It could be used as an alternative intracanal medicament. Keywords: Root canal medicaments, Enterococcus faecalis, Staphylococcus aureus, Candida albicans, Propolis. How to cite this article: Mattigatti S, Jain D, Ratnakar P, Moturi S, Varma S, Rairam S. Antimicrobial Effect of Conventional Root Canal Medicaments vs Propolis Against Enterococcus faecalis, Staphylococcus aureus and Candida albicans. J Contemp Dent Pract 2012;13(3):305-309. Source of support: Nil Conflict of interest: None declared.     

Antimicrobial substantivity of chlorhexidine-treated bovine root dentin

Previous studies have demonstrated antimicrobial substantivity in root canal dentin up to 7 days after treatment with chlorhexidine. This in vitro study assessed the antimicrobial substantivity of chlorhexidine-treated bovine root dentin over a period of 21 days. Sixty standardized bovine root sections were randomly divided into three equal groups, and their canals immersed in one of the following solutions: (i) sterile saline; (ii) 2.5% NaOCl; or (iii) 0.2% chlorhexidine (CHX). Half the specimens in each group were treated with the solution for 5 min and the other half for 7 days. After solutions were removed, the specimens were incubated at 37 degrees C in Brain Heart Infusion broth containing Enterococcus faecalis (ATCC 29212). A fresh inoculum was added to the broth every other day over a 21-day period. The canals were then enlarged with sterile burs, and the dentin shavings collected and cultured for the presence of cultivable bacteria in the dentinal tubules. Specimens treated with CHX for 7 days demonstrated significantly less dentin colonization by E. faecalis than the other specimens. CHX has potential as an intracanal medicament, if it can be applied for a period of at least 7 days.     

Evaluation of Morinda citrifolia as an endodontic irrigant

The purpose of this study was to compare the in vitro effectiveness of Morinda citrifolia juice (MCJ) with sodium hypochlorite (NaOCl) and chlorhexidine gluconate (CHX) to remove the smear layer from the canal walls of endodontically instrumented teeth. Sixty extracted, single-rooted, mature, permanent, human premolar teeth with a single canal were inoculated with Enterococcus faecalis at 37 degrees C in a CO2 atmosphere for 30 days. The teeth were randomly allocated to 6 treatment groups; the pulp chamber was accessed, cleaned, and shaped by using ProTaper and ProFile rotary instrumentation to a size 35. During instrumentation the irrigation was provided by MCJ, NaOCl, CHX, MCJ/CHX, followed by a final flush of 17% ethylenediaminetetraacetic acid (EDTA). MCJ irrigation was also followed by a final flush of saline, and saline irrigation was also used as a negative control. The teeth were then processed for scanning electron microscopy, and the removal of smear layer was examined. Data were analyzed by chi2 statistical tests (P values) at a significance of 95%. The most effective removal of smear layer occurred with MCJ and NaOCl, both with a rinse of 17% EDTA. Both MCJ and NaOCl treatments were similarly effective with a rinse of 17% EDTA (P < .2471) to completely remove up to 80% of the smear layer from some aspects of the root canal. MCJ was more effective than CHX for removing smear layer (P < .0085) and saline as the negative control (P < .0001). The efficacy of MJC was similar to NaOCl in conjunction with EDTA as an intracanal irrigant. MJC appears to be the first fruit juice to be identified as a possible alternative to the use of NaOCl as an intracanal irrigant.     

Effect of sodium hypochlorite and five intracanal medications on Candida albicans in root canals

The aim of this study was to evaluate the effect of 1% sodium hypochlorite and five intracanals medications on Candida albicans harvested inside root canals. The contaminated canals were irrigated with sterile saline solution and then treated as follows: (i) filled with Calen paste (calcium hydroxide/ glycol polyethylene paste); (ii) filled with camphorated paramonochloro phenol (CPMC); (iii) filled with 2% iodine-iodate solution; (iv) filled with tricresol formalin; (v) filled with Calen and CPMC pastes; (vi) irrigation with 1% sodium hypochlorite and filled with no intracanal medication; and (vii) no intracanal medication was used. Canal access and the apical foramen were then sealed with Cavit and the roots were stored in a humid chamber at 37 +/- 1 degree C for 14 days. The canals were reinstrumented and irrigated with sterile saline solution. Sterile paper points were used to transfer the root canal contents to test tubes containing sterile saline solution. Part of the suspension was harvested in Sabouraud dextrose agar with chloramphenicol and incubated at 37 +/- 1 degree C for 48 h. CPMC was effective in 100% of the samples followed in decreasing order of effectiveness by calcium hydroxide with CPMC (70% effective), 1% sodium hypochlorite (70% effective) (p < 0.05), tricresol formalin (60% effective), 2% iodine-iodate solution (50% effective), calcium hydroxide paste (30% effective), and saline + no intracanal medication.     

Bacterial reduction in infected root canals treated with 2.5% NaOCl as an irrigant and calcium hydroxide/camphorated paramonochlorophenol paste as an intracanal dressing

This clinical study investigated the bacterial reduction after instrumentation using 2.5% sodium hypochlorite (NaOCl) as an irrigant and further interappointment dressing with a calcium hydroxide (Ca(OH)(2))/camphorated paramonochlorophenol (CPMC) paste. Eleven teeth with primary intraradicular infections and chronic apical periodontitis selected according to stringent inclusion/exclusion criteria followed in the study. Bacterial samples were taken before treatment (S1), after chemomechanical preparation using hand NiTi files and 2.5% NaOCl (S2), and following a 7-day medication with a Ca(OH)(2) paste in CPMC (S3). Cultivable bacteria recovered from infected root canals at the three stages were counted and identified by means of 16S rRNA gene sequencing analysis. At S1, all cases harbored bacteria, with a mean number of 2.8 taxa per canal (range, 1-6). At S2, 6 of 11 (54.5%) of the cases yielded positive cultures, with one to three species per canal. At S3, only one case (9.1%) was positive for the presence of bacteria, with Propionibacterium acnes as the only taxon isolated. A significantly high reduction in bacterial counts was observed between S1 and S2, and S1 and S3. Significant differences were also observed for comparisons involving S2 and S3 samples with regard to both quantitative bacterial reduction (p = 0.029) and number of culture-negative cases (p = 0.03). It was concluded that chemomechanical preparation with 2.5% NaOCl as an irrigant significantly reduced the number of bacteria in the canal but failed to render the canal free of cultivable bacteria in more than one-half of the cases. A 7-day intracanal dressing with Ca(OH)(2)/CPMC paste further significantly increased the number of culture-negative cases.     

Antimicrobial action of calcium hydroxide, chlorhexidine and their combination on endodontic pathogens

BACKGROUND: The common recovery of Candida albicans and Enterococcus faecalis from failed root canals of teeth in which previous treatment has failed is notable. These organisms have been shown to be resistant to antimicrobial action of calcium hydroxide but are sensitive to chlorhexidine gluconate. The aim of the present in vitro study was to investigate the antimicrobial efficacy of calcium hydroxide paste, 2% chlorhexidine gel and their combination against Candida albicans and Enterococcus faecalis. METHODS: Inoculae of these organisms were used to make lawn cultures on Sabouraud's dextrose agar and blood agar plates. Wells were prepared with these lawn cultures and filled with calcium hydroxide paste, 2% chlorhexidine gel and their combination. The agar plates were kept overnight for incubation at 37 degrees C and the zone of inhibition was examined after 24 and 72 hours. RESULTS: The results suggest that 2% chlorhexidine gel alone is more effective at 72 hours than calcium hydroxide paste alone or in combination with 2% chlorhexidine gel against both the organisms, even though calcium hydroxide showed better antifungal efficacy against Candida albicans at 24 hours. CONCLUSION: In failed root canal treatments, 2% chlorhexidine gel may be a more effective intracanal medicament than calcium hydroxide paste or their combination against Candida albicans and Enterococcus faecalis.     

Antimicrobial efficacy of a polymeric chlorhexidine release device using in vitro model of Enterococcus faecalis dentinal tubule infection

This study aimed to assess the antimicrobial efficacy of a novel polymeric chlorhexidine-controlled release device as an intracanal medicament. One hundred cylindrical dentin blocks prepared from human single-rooted teeth were inoculated with Enterococcus faecalis for 3 weeks. The intracanal medicaments tested were calcium hydroxide, a polymeric chlorhexidine-controlled release device (PCRD), a polymeric controlled release device without chlorhexidine (CHx), 0.2% CHx solution, and sterile saline. Dentin samples (at 200-mum and 400-mum depths) were collected from the medicated canal lumens after 1 week of medication with sterile LightSpeed files and placed in growth medium. Bacterial growth was assessed spectrophotometrically by analysis of optical density (OD) after 24 hours of incubation. The OD values at both depths were significantly lower in the PCRD group than in the other experimental groups (P < .001). These results indicate that a PCRD can be an effective intracanal medicament against E. faecalis.     

Effectiveness of propolis and calcium hydroxide as a short‐term intracanal medicament against Enterococcus faecalis: A laboratory study

The aim of this study was to investigate the antimicrobial activity of propolis‐based intracanal medicament against Enterococcus faecalis using infected dentine models, and to compare its antimicrobial efficacy with that of the non‐setting calcium hydroxide paste when used as a short‐term medication for 1 and 2 days. A total of 50 dentine discs of 7‐mm length was obtained from extracted human teeth. Five dentine discs were kept sterile to serve as a negative control. The remaining 45 were contaminated with E. faecalis and divided into two groups (n = 20) in addition to five discs that served as a positive control. The discs were treated as follow: 20 discs were filled with propolis, while the other 20 discs were filled with non‐setting calcium hydroxide. Microbiological sampling was performed utilising sterile paper point, headstrom file and disc immersion. Results showed that propolis was significantly more effective than non‐setting calcium hydroxide against E. faecalis after short‐term application, which made comparison from this prospect unlevelled. The most effective microbiological sampling technique was abrading the lumen with headstrom file. Propolis is very effective as intracanal medicament in rapidly eliminating E. faecalis ex vivo.     

Antimicrobial efficacy of chlorhexidine and two calcium hydroxide formulations against Enterococcus faecalis

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.     

Evaluation of the antimicrobial effect of Er:YAG laser irradiation versus 1% sodium hypochlorite irrigation for root canal disinfection

This laboratory study evaluated Er:YAG laser antibacterial action in infected root canals. Forty-eight maxillary central incisors were used. After canal preparation, the teeth were autoclaved and divided into four groups: (1) non-treated teeth (control group); (2) teeth treated with NaOCl; (3) teeth irradiated with Er:YAG laser (7 Hz, 100 mJ, 80 pulses/canal, 11 sec) to the working length; (4) teeth irradiated similarly to, but 3 mm short, of the apex. The root canals from Groups 2, 3 and 4 were inoculated with 4 bacteria: Bacillus subtillus, Enterococcus faecalis, Pseudomonas aeruginosa, and Staphylococcus aureus, together with Candida albicans, and maintained for 24 h at 37 degrees C. All suspensions were adjusted to tube 2 of the MacFarland scale. The intracanal material was then collected with sterile paper points, which were placed in the canals for 5 min and then immersed in 5 ml of BHI medium. This was then seeded onto agar and stained by Gram's method. The NaOCl solutions and the Er:YAG laser irradiation to working length were effective against all five micro-organisms; however, 70% of the specimens irradiated 3 mm short of the apex remained infected.     

Additive effect of a diode laser on the antibacterial activity of 2.5% NaOCl, 2% CHX and MTAD against Enterococcus faecalis contaminating root canals: an in vitro study

This in vitro study was performed to evaluate the effect of a diode laser and common disinfectants used in combination on mono-infected dental canals. One hundred and six single-rooted human premolars were prepared and contaminated with Enterococcus faecalis. After two weeks of incubation, samples were divided into two experimental groups (n = 48) and two control groups (n = 5). In the first group, the teeth were rinsed for 5 min with either sterile saline, 2.5% NaOCl, or MTAD, or for 1 min with 2% chlorhexidine gluconate (CHX). In the other group, samples were additionally irradiated with a 810-nm diode laser at 2 W output for 5 × 5 s. Intracanal bacterial sampling was done, and the samples were plated to determine the CFU count. In the first group, 2.5% NaOCl was as effective as 2% CHX and significantly more effective than MTAD (P < 0.008). In the second group, either MTAD, 2% CHX or 2.5% NaOCl in combination with laser treatment had a similar effect. Absence of growth was seen only for MTAD plus laser treatment. Complete elimination of E. faecalis was seen only for the combination of MTAD with diode laser irradiation. Combination therapy with MTAD irrigation and diode laser irradiation, within the parameters used in this study, can be recommended as an effective treatment option for complete elimination of E. faecalis from the root canal system.     

Microbial analysis of endodontic infections in teeth with post-treatment apical periodontitis before and after medication

This study aimed to determine the intraradicular microbiota of previously root canal-treated teeth with apical periodontitis and to investigate the antibacterial effectiveness of different intracanal medicaments. Sixteen patients with post-treatment apical periodontitis were allocated into two groups according to the intracanal medicament used: calcium hydroxide (CH) and 2% chlorhexidine gluconate gel (CHX) group. Total bacterial loads, as well as the amount of Enterococcus faecalis (E. faecalis) were determined before (S1) and after (S2) chemomechanical preparation and finally, after intracanal medication (S3) by means of ddPCR. The unpaired t test was used to compare parametric. S3-total bacteria copy number of the CH group was lower than the CHX group (p < 0.05). There was no statistical difference between the CHX- and the CH groups in terms of E.faecalis copy number (p > 0.05). But in terms of total bacteria, CH is better than CHX. Consequently, CH can be used to optimise the antibacterial efficiency of chemomechanical preparation in previously root canal-treated teeth with apical periodontitis.     

In vitro evaluation of the action of irrigating solutions associated with intracanal medications on Escherichia coli and its endotoxin in root canals

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.     

In vitro antifungal efficacy of four irrigants as a final rinse

The purpose of this study was to compare the antifungal efficacy of 6% sodium hypochlorite (NaOCl), 2% chlorhexidine gluconate (CHX), 17% ethylene-diaminetetraacetic acid (EDTA), and BioPure MTAD as a final rinse on Candida albicans in vitro. Forty-eight, single rooted teeth were randomly divided into four groups each with a positive and a negative control. After root canal preparation, experimental teeth were inoculated with Candida albicans (ATCC 60193) and incubated for 72 hours. The groups were rinsed as follows: 1 ml of 6% NaOCl, 0.2 ml of 2% CHX, 1 ml of 17% EDTA, and 5 ml of BioPure MTAD. Aliquots from the experimental teeth were plated on Sabouraud 4% dextrose agar plates and colony-forming units were counted as a measure of antifungal activity. The results showed that 6% NaOCl and 2% CHX were equally effective and statistically significantly superior to BioPure MTAD and 17% EDTA (p < 0.05) in antifungal activity.     

Clinical and laboratory assessments of camphorated monochlorophenol in endodontic therapy

The purpose of this study was to evaluate the effect of camphorated monochlorophenol (CMCP) on bacterial status of root canals of nonvital teeth during treatments. The presence of bacteria in 15 single-rooted teeth with periapical lesions was studied throughout a whole period of treatment. Patients were randomly divided into three groups. In group 1, a control group, the intracanal medication was omitted. The teeth were enlarged under aseptic conditions in combination with the use of 3% H2O2 and 5.25% NaOCl as irrigants. In group 2, after chemomechanical preparation, the root canals were dressed with 2 microliter of 40% CMCP. The medicament was replaced on days 3 and 7. In group 3, root canals were treated in a manner similar to those in group 2, except that the medicament was renewed on days 1 and 7. The loss of CMCP was determined in groups 2 and 3. The results showed that chemomechanical preparation could reduce bacteria in root canals to an uncultivable number. Approximately 62.5% of the original concentration of CMCP was lost after placement in root canals for 1 day. Intracanal dressing with CMCP between appointments induced a rapid decrease in number of bacteria in root canals within the first 1 to 3 days. However, compared to chemomechanical preparation, the antimicrobial effect of CMCP was not clinically impressive because negative cultures also could be observed despite the absence of intracanal medications.     

Proportion of Healed Teeth With Apical Periodontitis Medicated With Two Percent Chlorhexidine Gluconate Liquid: A Case-Series Study

IntroductionChlorhexidine gluconate (CHX) is a potential intracanal medicament, but data on healing after its use are lacking. Previously we reported on bacterial sampling in 22 teeth with apical periodontitis medicated with CHX. This study assessed healing in those teeth.MethodsCanals were instrumented and medicated with 2% CHX liquid for 7–15 days and subsequently irrigated and filled. Bacterial samples were taken before and after instrumentation, after medication and before root filling, and enumerated by culture and vital microscopy. After 2–4 years, subjects were examined clinically and radiographically by assigning Periapical Index scores by independent calibrated examiners. Outcome was dichotomized as healed or disease.ResultsWith 2 teeth extracted, 1 deceased subject, and 2 nonrespondents, 16 of 17 examined teeth (94%) were healed without association with bacterial sampling results. The proportion of healed teeth in this study did not differ significantly (Fisher exact test; P = .20) from that in a historical control (90%).ConclusionsThe results suggested a comparable outcome after medication with 2% CHX liquid and calcium hydroxide.     

Monitoring the effectiveness of root canal procedures on endotoxin levels found in teeth with chronic apical periodontitis

Objective:

The aim of this study was to monitor the effectiveness of root canal procedures by using different irrigants and intracanal medication on endotoxin levels found in root canals of teeth with chronic apical periodontitis.

Material and Methods:

Thirty root canals of teeth with pulpal necrosis associated with periapical lesions were selected and randomly divided into groups according to the irrigants used: GI - 2.5% NaOCl, GII - 2% chlorhexidine (CHX) gel, and GIII - saline solution (SS) (all, n=10). Samples were collected with sterile/apyrogenic paper points before (S1) and after root canal instrumentation (S2), after use of 17% ethylenediaminetetraacetic acid (EDTA) (S3), and after 30 days of intracanal medication (Ca(OH)₂+SS) (S4). A turbidimetric kinetic Limulus Amebocyte Lysate assay was used for endotoxin measurement.

Results:

Endotoxins were detected in 100% of the root canals investigated (30/30), with a median value of 18.70 EU/mL. After S2, significant median percentage reduction was observed in all groups, irrespective of the irrigant tested: 2.5% NaOCl (99.65%) (GI), 2% CHX (94.27%) (GII), and SS (96.79%) (GIII) (all p<0.05). Root canal rinse with 17% EDTA (S3) for a 3-minute period failed to decrease endotoxin levels in GI and a slight decrease was observed in GII (59%) and GIII (61.1%) (all p>0.05). Intracanal medication for 30 days was able to significantly reduce residual endotoxins: 2.5% NaOCl (90%) (GI), 2% CHX (88.8%) (GII), and SS (85.7%) (GIII, p<0.05). No differences were found in the endotoxin reduction when comparing s2 and s4 treatment groups.

Conclusion:

Our findings demonstrated the effectiveness of the mechanical action of the instruments along with the flow and backflow of irrigant enduring root canal instrumentation for the endotoxin removal from root canals of teeth with chronic apical periodontitis. Moreover, the use of intracanal medication for 30 days contributed for an improvement of endotoxin reduction.