Evaluation of the effect of different irrigation solutions on the microhardness of heat-treated nickel-titanium files: An in vitro study.

To evaluate the effect of different irrigation solutions on the bonding of self-adhesive composite cements to the root canal during fiber-post cementation. One hundred twenty single-rooted human teeth were endodontically treated. The post spaces were prepared and specimens were randomly divided into ten groups, according to the combination of the factors: post space irrigation (distilled water, 2.5% NaOCl, 17% EDTA, 26% polyacrylic acid, and 17% EDTA + 2.5% NaOCl) and self-adhesive composite cement (RelyX U200 [3M Oral Care] and Multilink Speed [Ivoclar Vivadent]). The proportion of open dentinal tubules was evaluated by SEM. After fiber post cementation, six slices were obtained from each root (coronal, middle, and apical thirds) for evaluation of push-out bond strength (BS), nanoleakage (NL), and Vickers microhardness (VHN) of the composite cement. Data from open dentinal tubules were submitted to Kruskal-Wallis and Student-Newman-Keuls tests (α = 0.05). Data from BS, NL, and VHN were evaluated by two-way ANOVA and Tukey's test (α = 0.05). Irrigation with EDTA, polyacrylic acid, and EDTA + NaOCl increased the proportion of open dentinal tubules. For RelyX U200, NaOCl, distilled water and EDTA resulted in the highest BS and VHN values, while for Multi- link Speed, these values were higher only for distilled water. Both composite cements presented lower BS and VHN with polyacrylic acid. NL did not differ between experimental groups (p > 0.05). For both composite cements tested, distilled water showed better results in push-out and microhardness tests.

Background: The coronal microleakage in the endodontically treated teeth causes recurrent caries and can be associated with the restoration and the root canal treatment failures. Intra orifice barrier is an efficient alternative method to decrease coronal leakage in endodotically treated teeth and one of the best barriers is glass ionomer. The current study propose that using different irrigation solutions in root canals effect on coronal microleakage.
 Purpose: This study aimed to compare the coronal microleakage in glass ionomer obturated root canals in endodontically treated teeth using different irrigation solutions.
 Methods: Sixty extracted human single-rooted teeth with single canals were collected and disinfected with 0.5 choloro amin. After root canal therapy and evacuation of 2 mm coronal gutta percha, the teeth were divided into 3 groups of each 20, based on irrigation solutions. Glass ionomer was used as the coronal barrier and the teeth were stored in distilled water. The irrigation solutions used were: 17% EDTA, Alcohol and normal saline. Then all the specimen were submerged in 2% methylene blue dye for 24 hours at room temperature and sectioned sagittally and the dye penetration was assessed by stereomicroscope.
 Results: There were not penetration of dye only in 3.3% of teeth and all of the teeth that irrigated with saline showed dye penetration. The dye penetration was seen in 95%, 95% and 100% of the EDTA, alcohol and saline groups, respectively. Dye penetration was higher in Saline group than other two groups but coronal microleakage has not shown statistically significant differences in different groups.
 Conclusion: The results of current study indicated that using different irrigation solutions may be associated with decrease in coronal microleakage. Although, based on our findings there are not any significant differences among different irrigation solutions but more studies may be needed to confirm this results.

Aim: The aim of this study was to compare the effect of three irrigating solutions on the apical sealing ability of three endodontic sealers when the continuous wave obturation technique was used.Materials and Methods: 100 maxillary central incisors were decoronated and roots were divided into three experimental groups (n=30 each) according to the type of irrigating solution, and two control groups (n=5 each). Each experimental group was divided equally into three subgroups according to the type of obturation system. All canals were instrumented using ProTaper Universal rotary system and irrigated with 3% sodium hypochlorite (Group 1), 2% chlorohexidine (Group 2), and 3% hydrogen peroxide (Group 3), followed by 17% EDTA and distilled water. Continuous wave technique was used to obturate root canals with the following combinations: MTA Fillapex/Gutta-percha (Subgroup A), AH Plus/Gutta-percha (Subgroup B) and Realseal SE/Realseal (Subgroup C). The apical microleakage was assessed using linear dye penetration method and the data were statistically analyzed. Results: Significant differences were found between all groups (P<0.05). All root canal sealers after irrigation with 3% hydrogen peroxide showed the lowest amounts of apical leakage. Samples irrigated with 3% sodium hypochlorite or 2% chlorohexidine showed the highest amounts of apical leakage. Conclusions: The type of irrigating solution could affect the apical sealing ability of experimental sealers when used with the continuous wave obturation technique. Root canal irrigation with 3% hydrogen peroxide + 17% EDTA increased the sealing ability of all root canal sealers. Root canal irrigation with 3% sodium hypochlorite 2% chlorohexidine + 17% EDTA decreased the sealing ability of all root canal sealers.

Antimicrobial efficacy of endodontic irrigation solutions against planktonic microorganisms and dual-species biofilm

IIrrigation solutions used and time of use has a definite effect on the micro hardness &amp; other physical properties of dentin which in turn have direct consequence on the longevity functional performance of root canal treated teeth. To evaluate the effect of different irrigation solutions on micro hardness of root dentin.Forty extracted single rooted lower premolars were used. After instrumentation all the root halves were randomly assigned into 4groups (n=10) and brought in contact with one of the following irrigants for 5 minutes. Group I: 10 ml of 5% Sodium Hypochlorite (NaOCl).Group II: 10 ml of 17% ethylene diamine tetra-acetic acid (EDTA) followed by 10 ml of 5% NaOCl.Group III: 10 ml of 5% NaOCl followed by 10 ml of 2% chlorhexidine digluconate (CHX).Group IV: 10 ml of 5% NaOCL followed by flush of 10 ml distilled water then by 10ml of 2% CHX. Dentin micro hardness was measured at baseline and after treatment to determine the change in micro hardness, using Vickers tester.Data was analyzed using following parametric tests t-test, ANOVA test and Post Hoc test. Group II ie final irrigation with EDTA showed the highest percentage decrease in micro hardness values, followed by group III, then group IV and the lowest was group I. All groups showed a significant difference between each other (P &amp;#60; 0.05), except group III and IV. The coronal third showed the highest percentage decrease with significant difference between apical and middle thirds (P &amp;#60; 0.05).EDTA with NaOCl causes greatest changes in dentine micro hardness, an intermediate flush with normal saline should be given for prevention of precipitation with NaOCl &amp; CHX.

During endodontic therapy, irrigation solutions applied in the root canal may affect the physicochemical properties of the dentinal wall, thereby changing its microhardness. This may adversely affect the sealing ability and adhesion of dental materials. Therefore, many studies have focused on the search for an ideal root canal irrigant that has a minimal effect on dentinal microhardness. This in vitro study was conducted to determine the changes in dentin microhardness after root canal irrigation with different endodontic irrigants. Ninety-five freshly extracted maxillary central incisor teeth with straight single canals were selected. These teeth were sectioned transversely at the level of the cementoenamel junction. The working length of each tooth was determined, and canal space was prepared by the HyFlex CM rotary file system. During instrumentation, normal saline was used for irrigation. Then, teeth were split longitudinally into two segments. According to the irrigating solution employed, samples were divided into five groups (n=19): normal saline (Group A), 3% sodium hypochlorite (Group B), 2% chlorhexidine (Group C), 5% calcium hypochlorite (Group D), and 0.2% nanochitosan (Group E).3 mL of the corresponding irrigating solution was administered for total15 minutes in each prepared sample. The Vickers micro-hardness tester was then used to assess micro-hardness. The data was analyzed using one-way analysis of variance (ANOVA). All tested irrigating solutions decreased the dentinal microhardness. Samples irrigated with 5% calcium hypochlorite demonstrated dentinal microhardness of 42.43±1.62, which is the lowest among all the tested groups, followed by nano chitosan, sodium hypochlorite, and chlorhexidine. Samples treated with control group (saline) demonstrated the maximum microhardness of dentin in the present study. Within the limitations of this research, it can be concluded that the tested novel irrigating solutions, 5% calcium hypochlorite and 0.2% nanochitosan, were more detrimental to radicular dentin microhardness when compared with conventional endodontic irrigants.

Objectives: The objective of this study was to compare the dissolution effects of different chemical solutions, which are commonly used as root canal irrigants, on partially or fully set mineral trioxide aggregate (MTA). Furthermore, the impact of these solutions on dentin microhardness was also assessed. Methods: In this study, a total of 80 extracted single-rooted human teeth were utilized. The roots of the teeth were bisected transversely into slices of 6 mm in length. MTA (NeoPUTTY, Avalon Biomed, USA) was applied in layers of 4 mm in thickness within the cavities, sealed with moist cotton, and stored at 37°C under 100% humidity for 24 hours and 21 days. Forty samples were tested at the 24-hour mark, and the remaining 40 samples were tested at the 21-day mark. The samples were randomly allocated to one of five experimental groups: 17% EDTA, 5.25% NaOCl, 2% CHX, 40% citric acid, and saline (control). The Vickers microhardness test was employed to ascertain the hardness values of the MTA and dentin surfaces that had been exposed to the chemical solutions for a period of 10 minutes. Statistical analyses were performed using MedCalc® v19.7.2 (MedCalc Software Ltd, Belgium), with a significance level set at 0.05. Results: It was observed that the application of EDTA, NaOCl, CHX, and citric acid solutions resulted in statistically significant reductions in the microhardness of both NeoPUTTY MTA (respectively p= .012; p= .012, p= .010; p= .012) and dentin (respectively p= .011; p= .012; p= .012; p= .012). The citric acid group exhibited the most pronounced reduction of MTA (respectively 52.2±1.6; -39±0.9). In contrast, no statistically significant change in microhardness was observed in the control group treated with saline (for dentin p= .311; for MTA p= .415). The impact of the solutions on MTA at 21 days was found to be less pronounced than that observed at 1 day (p= .012). Conclusion: The results of this study indicate that the application of citric acid solutions to MTA results in a statistically significant reduction in microhardness. The highest concentration of citric acid was observed to be more effective than the other solutions in the dissolution of MTA. However, these solutions were also found to significantly reduce the microhardness of dentin. It would be advisable to select solutions that facilitate the removal of MTA without damaging the dentin tissue.

Although the sodium hypochlorite (NaOCl) solution has been part of the endodontic arsenal for more than one century, current investigations have been unable to determine which NaOCl volume and concentration or which time of application are able to dissolve organic matter without weakening the dental structure during the phase of biomechanical preparation of the root canal. Thus, the objective of the present study was to conduct a systematic literature review with no restriction of publication year or language in order to resolve these questions. The search strategy included the following databases: PubMed, LILACS, Web of Science and ClinicalTrials.gov, and only in vivo human clinical trials were included in the final review. After the removal of duplicates, the systematic literature review yielded 3,717 articles. Of these, 3,685 were excluded after applying the exclusion criteria (ex vivo studies, animal studies, cell-culture studies, narrative review, and studies with no available full texts). A total of 32 full-text articles were assessed for eligibility. After evaluating the full text, all articles were excluded for different reasons. No studies fulfilled our inclusion criteria. This review was unable to answer what time of irrigation, concentration or volume of NaOCl solution can be of maximum effectiveness in endodontic treatment without producing significant changes in the mechanical properties of dentin. Thus, future human clinical studies are needed in order to resolve these questions.Descriptors: Endodontics; Sodium Hypochlorite; Review.ReferênciasSiqueira JF Jr, Guimarães-Pinto T, Rôças IN. Effects of chemomechanical preparation with 2.5% sodium hypochlorite and intracanal medication with calcium hydroxide on cultivable bacteria in infected root canals. 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Comparison of 2% chlorhexidine and 5.25% sodium hypochlorite irrigating solutions on postoperative pain: a randomized clinical trial. Indian J Dent Res.2010;21(4):523-27.Haapasalo M, Shen Y, Qian W, Gao Y. Irrigation in endodontics. Dent Clin North Am. 2010;54(2):291-312.Huffaker SK, Safavi K, Spangberg LS, Kaufman B. Influence of a passive sonic irrigation system on the elimination of bacteria from root canal systems: a clinical study. J Endod. 2010;36(8):1315-18.Kandaswamy D, Venkateshbabu N. Root canal irrigants. J cons dent.2010;13(4),256-64.Kaya S, Yiğit-Özer S, Adigüzel O. Evaluation of radicular dentin erosion and smear layer removal capacity of self-adjusting file using different concentrations of sodium hypochlorite as an initial irrigant. Oral Surg Oral Med Oral Pathol Oral Radiol and Endod.2011;112(4):524-30.Paudel KR, Jaiswal A, Parajuli U, Bajracharya M. Different pharmacological solutions in intracanal irrigation. 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The effects of sodium hypochlorite and chlorhexidine irrigants on the antibacterial activities of alkaline media against Enterococcus faecalis. Arch Oral Biol.2015;60(7):1075-81.Podar R, Kulkarni GP, Dadu SS, Singh S, Singh SH. In vivo antimicrobial efficacy of 6% Morinda citrifolia, Azadirachta indica, and 3% sodium hypochlorite as root canal irrigants. Eur J Dent.2015;9(4):529-34.Arias-Moliz MT, Morago A, Ordinola-Zapata R, Ferrer-Luque CM, Ruiz-Linares M, Baca P. Effects of dentin debris on the antimicrobial properties of sodium hypochlorite and etidronic acid. J Endod. 2016;42(2):771-75.Rôças IN, Provenzano JC, Neves MA, Siqueira JF Jr. Disinfecting effects of rotary instrumentation with either 2.5% sodium hypochlorite or 2% chlorhexidine as the main irrigant: a randomized clinical study. J Endod. 2016;42(6):943–47.Kist S, Kollmuss M, Jung J, Schubert S, Hickel R, Huth KC. 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The objective of this research was to assess the effects of several irrigation solutions (ISOLs) on two major (P and Ca) and some minor (Fe, Zn, and Sr) elements of multi-root canals of radicular dentin in upper premolar teeth using X-ray fluorescence analysis (XRF). Powder of fifty radicular dentin specimens were prepared and divided into five groups based on treatments with different single and combined ISOLs. These groups were: G1-distilled water (control); G2- sodium hypochlorite (NaOCl, 5.25%); G3- sodium hypochlorite (NaOCl, 5.25%) and ethylendiaminetetraacetic acid (EDTA, 17%); G4- distilled water and a mixture of tetracycline, an acid, and a detergent (MTAD); and G5- sodium hypochlorite (NaOCl, 1.3%) and MTAD. The XRF results confirmed that the ISOL G5 (Ca/P=1.6254) was the most effective one. The ratio-to-ratio correlations revealed the common origins of Fe, Zn, and Sr in root canals of radicular dentin, which was highly interacted with the major elements of P and Ca each. These interactions were insignificantly affected by the used ISOLs. Finally, XRF is highly recommended as a safe, fast, nondestructive, and relatively not expensive technique to analyze the endodontic therapy of teeth.

Objectives: To examine the success rate of root canal treatment in primary molars with the use two different root canal instrumentation ways, irrigation solutions and root canal sealers. Materials and Methods: Root canal treatment was applied to 120 second primary molars of 69 children between 5-8 years old. The teeth were divided in 8 groups randomly according to instrumentation ways [conventional stainless-steel hand files / Nickel-titanium (Ni-Ti) rotary files], irrigation solutions [0.5% sodium hypochlorite (NaOCl) and 0.9% saline solution combination / 0.4% chlorhehexidine (CHX)] and root canal sealers [Zinc oxide eugenol cement (ZOE) and Apexit Plus (AP)]. All teeth were restored with stainless steel crowns. The teeth were followed 12 months both clinically and radiographically. All data was analyzed statistically by χ 2 and Wilcoxon test. Results: Statistical significance were found according to “age” and “root canal sealers” factors on success rate of root canal treatment (p 0.05). The clinically and radiographically success rate of ZOE and AP were 98.3% and 68.3%, respectively. Conclusions: Root canal treatment is a successful treatment in primary molars. Ni-Ti rotary files and CHX can be a good alternative for root canal treatment in primary molars. The most effective factor to obtain clinical success of root canal treatment is properties of using root canal sealer.

ObjectiveTo study effect of root canal irrigant solutions on the bond strength of cemented fiber posts, and resin cement-tags in root canal dentin.Materials and methodsFifty-two human single-rooted anterior teeth were selected and stored in 1% sodium azide. Crowns were sectioned 2 mm incisal to the cemento enamel junction with diamond bur at high speed under water-cooling. After standard root canal treatment to tested teeth, they were randomly assigned into four groups (n=13) corresponding to the endodontic irrigant solution that was used during post space preparation. The treatment groups were: Group 1: 6.15% sodium hypochlorite; Group 2: 17% EDTA; Group 3: 6.15% NaOCl +17% EDTA; Group 4: 6.15% NaOCl +0.12% chlorhexidine solution. Parallel-sided fiber posts were used for all specimens. Samples were embedded in a cylindrical PVC mounting jig to facilitate perpendicular sectioning. With low speed diamond saw, cervical and apical specimens from each tooth were obtained and subjected to push-out test using universal testing machine. SEM was used to examine the root-canal dentin surface.ResultsStatistical analysis revealed significant difference among the groups at P<0.05. Group 2 treated with EDTA, had the highest bond strength; 18.63±2.85 MPa in cervical specimens and 13.49±3.67 MPa in apical specimens. The cervical specimens of Groups 2 and 3 were significantly different than the apical specimens in the same group. Adhesive failure between cement and dentin was the main failure mode observed in all groups. Groups irrigated with EDTA showed cleaner dentin surface and better resin tag formation, while groups treated with NaOCl showed less resin tag formation and insufficient smear layer removal.ConclusionNaOCl had adverse effect on bond strength of self-adhesive resin cement to radicular dentin. EDTA irrigant solution produced higher bond strength and was more effective in removing smear layer than NaOCl.

Introduction: Modifications in the mechanical properties of dentin may reduce the fracture resistance of tooth, especially after endodontic treatment. The aim of present study was to evaluate the effect of the irrigation with different root canal irrigants on the microhardness of root dentin. Methods: The coronal portion of 60 single-rooted bovine incisors was sectioned and the pulpal tissue removed using endodontic K-files. The roots were cut transversely to obtain 2 fragments, which were embedded in acrylic resin and randomly distributed into six groups (n=20) according to the irrigation protocol: distilled water (DW) (control); 2% chlorhexidine solution (CHX); 6% sodium hypochlorite (NaOCl); 6% calcium hypochlorite (Ca[OCl]2); QMix; and 6.5% grape seed extract solution (GSE). The solutions were kept in contact with the root dentin specimens for 30 min. After that, irrigation with 5 mL of DW was performed. The Vickers microhardness was determined by performing three indentations in all specimens, using 300-g load and 20-second dwell time. The first indentation was made 1.000 µm from the root canal entrance, and two other indentations were made at a distance of 200 µm from each other. The microhardness value for each specimen was obtained as the average of the results for the three indentations. Data were statistically analyzed using one-way ANOVA with 5% significance level. Results: All the tested irrigant solutions maintained the same microhardness level of the root dentin when compared to the control group, with no statistically significant differences between them (p&lt;0.05) Conclusion: The tested irrigant solutions did not present ability to modify the microhardness of root dentin.

The purpose of this study was to evaluate the efficiencies of different irrigation protocols in the removal of triple antibiotic paste (TAP) from root canals. A total of 127 extracted human maxillary incisor teeth were prepared. Then, root-end resection of 3 mm was accomplished to simulate immature apex model. The root canals were filled with TAP, after 21 days, randomly divided into nine groups according to irrigation systems and solutions (n = 13). Conventional irrigation (CI) groups - Group 1: Root canal irrigation was performed with CI by Peracetic acid (PAA) solution, Group 2: Root canal irrigation was performed with CI by etidronic acid 1-hydroxyethylidene-1, 1-bisphosphonate (HEBP) + sodium hypochlorite (NaOCl) solution, Group 3: Root canal irrigation was performed with CI by ethylenediaminetetraacetic acid (EDTA)/NaOCl solutions. Vibringe system groups - Group 4: Root canal irrigation was performed with Vibringe system by PAA solution, Group 5: Root canal irrigation was performed with Vibringe system by HEBP + NaOCl solution, Group 6: Root canal irrigation was performed with Vibringe system by EDTA/NaOCl solution. EndoVac system groups - Group 7: Root canal irrigation was performed with EndoVac system by PAA solution, Group 8: Root canal irrigation was performed with EndoVac system by HEBP + NaOCl solution, Group 9: Root canal irrigation was performed with EndoVac system by EDTA/NaOCl solution. Control Group: (n = 0). Samples were sectioned vertically, and the amount of remaining medicament was scored for each root half and data were statistically analyzed. Among the irrigation systems, CI groups showed the highest scores at both apical and coronal parts (P < 0.05). In comparisons among the solutions, at the apical part, PAA groups showed the highest scores (P < 0.05). At the coronal part, EDTA + NaOCl groups showed the lowest score values (P < 0.05). The use of irrigation systems improved the removal of TAP from the simulated immature root canals. Also, as an irrigation solution EDTA gives more promising results than PAA and HEBP solutions.

Introduction: Success in endodontic therapy largely depends on mechanical and chemical debridement of the root canals by using instruments and effective irrigating solutions which are not only important for cleaning and disinfecting the root canals, but also, are capable of altering the chemical and structural properties of dentin. As the microhardness test is sensitive to surface changes of tooth structure, it is useful in making a correlation between irrigating solutions and root dentin microhardness. Aim: To evaluate the effect of different standard irrigating solutions at standard concentrations and Stevia leaf extract (2.5%) on the microhardness of root canal dentin. Materials and Methods: This is an in-vitro comparative study where forty intact single rooted teeth were selected and decoronated to get an apico-coronal length of 10 mm and were randomly divided into four groups as per the irrigant used; Group 1 (control): Irrigation with Normal saline, Group 2: Irrigation with 2.5% Sodium Hypochloride (NaOCl) followed by 17% EDTA, Group 3: Irrigation with 2.5% Stevia extract solution, Group 4: Irrigation with SmearClear solution. They were prepared using ProTaper Universal Rotary Files with intermittent irrigation with the respective irrigating solution. The teeth were then embedded in acrylic resin and subjected to Vicker’s Hardness test and the data obtained were analysed using one way ANOVA test. p&lt;0.05 was taken to be statistically significant. Results: At 500 microns, Vickers Hardness Number (VHN) value was less than at 1000 micron, but was not statistically significant, (p&gt;0.05). Between the groups, the control group showed the highest microhardness at 500 and 1000 microns, namely, 51.27±4.36 VHN and 53.60±5.12 VHN, respectively. Group 3 and 4 showed a comparable reduction in microhardness with Group 3 showing slightly better results (47.98±4.34 VHN and 48.89±5.26 VHN, respectively) as compared to Group 4 (47.36±5.50 VHN and 48.62±5.84 VHN, respectively). Group 2 showed the least value (36.60±5.71 VHN and 37.11±5.82 VHN, respectively). Conclusion: Within the limitations of this study, teeth irrigated with normal saline showed least reduction in microhardness followed by irrigation with Stevia leaf extract solution, SmearClear and Hypochlorite followed by EDTA.

To evaluate the effect of biomechanical preparation with different irrigating solutions and calcium hydroxide dressing in dog root canals containing bacterial endotoxin (lipopolysaccharides; LPS). One hundred and forty premolar roots from seven dogs were filled with Escherichia coli LPS for 10 days (three roots were lost during histological processing). The following irrigating solutions were used for biomechanical preparation: 1% (group I, n = 20), 2.5% (group II, n = 19) and 5% sodium hypochlorite (group III, n = 19), 2% chlorhexidine digluconate (group IV, n = 20) and physiological saline solution (group V, n = 19). In group VI (n = 20), the LPS solution was maintained in the root canal during the entire experiment and in group VII (n = 20), after biomechanical preparation with saline solution, the root canals were filled with a calcium hydroxide dressing (Calen; control). After 60 days, the animals were sacrificed and the following parameters of periapical disease were evaluated: (a) inflammatory infiltrate, (b) periodontal ligament thickness, (c) cementum resorption and (d) bone resorption. Scores were given and data were analysed statistically with the Kruskal-Wallis and Dunn tests (P < 0.05). Histopathological evaluation showed that groups I-VI had more inflammatory infiltrate, greater periodontal ligament thickening and greater cementum and bone resorption (P < 0.05) compared to group VII, which received the calcium hydroxide intracanal dressing. Biomechanical preparation with the irrigating solutions did not inactivate the effects of the endotoxin but the calcium hydroxide intracanal dressing did appear to inactivate the effects induced by the endotoxin in vivo.