Microhardness Of Root Canal Dentin Research Articles

Effect of Various Acid Solutions as an Aid in Removing the OrthoMTA-Based Root Canal Filling

The objectives of this study were to compare the effects of various acid solutions combined with ultrasonics as an aid to remove mineral trioxide aggregate (MTA)-based root canal filling and to assess their effect on the surface topography and microhardness of root canal dentin. Materials and Method: Fifty human permanent single rooted and single canaled freshly extracted teeth were decoronated and sectioned apically to prepare the middle third of root sections of 5 mm length. The canals were prepared in a step-back manner. OrthoMTA was packed throughout the prepared canals. These root sections were incubated for one week and subsequently randomly allocated to five groups (n = 10) according to the OrthoMTA removal method: No treatment (NT); 5% glycolic acid + ultrasonics (5% GA+U); 10% glycolic acid + ultrasonics (10% GA+U); 10% citric acid + ultrasonics (10% CA+U); Distilled water + ultrasonics (DW+U). A 1 mm deep well was created within the coronal end of the set OrthoMTA. Wells were filled with each respective test solution and left for 5 min. Thereafter, further removal of OrthoMTA used a specific ultrasonic tip. Finally, the canals were flushed using 1 mL of the respective test solutions and activated with a Controlled Memory ultrasonic tip for two cycles of 20 s each followed by flushing with 1 mL of distilled water and paper point drying of the canals. Then, specimens were longitudinally split into two halves and examined under a scanning electron microscope (1000×) to assess the residual OrthoMTA and surface topography of root canal dentin. The Vickers surface microhardness of treated radicular dentin was measured using the HMV-2 microhardness tester. Result: Data were analysed using one-way ANOVA followed by Tukey’s post hoc test. Significant differences for residual OrthoMTA were observed between (10% GA+U) with (5% GA+U), (10% CA+U), (DW+U) and (NT) (p value < 0.01). In the context of microhardness, (5% GA+U) and (10% GA+U) showed statistically significant difference compared to (NT), (10% CA+U) and (DW+U) (p value < 0.01). Conclusion: 10% GA+U was superior to other tested groups in removing OrthoMTA, but it substantially reduced dentin microhardness.

Impact of Two Nano Irrigating Solutions on Microhardness of Root canal Dentin

Impact of Two Nano Irrigating Solutions on Microhardness of Root canal Dentin

A comparative evaluation of the effect of various chelating agents on the microhardness of root canal dentin: An in vitro study

A comparative evaluation of the effect of various chelating agents on the microhardness of root canal dentin: An in vitro study

The Effect of a Novel Silver-Citrate Root Canal Irrigation Solution (BioAkt), Ethylenediamine Tetraacetic Acid (EDTA), and Citric Acid on the Microhardness of Root Canal Dentin: A Comparative In Vitro Study.

Background and objective The use of a chelating agentas an adjunct to disinfectant irrigation is very necessary to remove the smear layer formed during root canal treatment. However, the decalcifying solutionshave a negative impact on dentin microhardness, which might affectthe result of endodontic therapy. The aim of this study is to evaluate the effect of 17% ethylenediamine tetraacetic acid (EDTA), a novel silver-citrate root canal irrigation solution (BioAkt), 10% citric acid, and 40% citric acid on the microhardness of root canal dentin. Materials and methods Forty-five single-root teeth were distributed equally into five groups A, B, C, D, and Etreated withdistilled water as a control, 17% EDTA, BioAkt, 10% citric acid, and 40% citric acid, respectively. The dentin microhardness was measured before and after the experiment, and the collected data were analyzed using paired sample T-test, One-way ANOVA test, and least significant difference (LSD) test (multiple comparisons), (P < 0.05). Result The results showed that the averages of dentin microhardness values before the experiment were 62.83 kg/mm², 65.34 kg/mm², 64.79 kg/mm², 62.95 kg/mm², and 56.47 kg/mm² for groups A, B, C, D, and E, respectively, while the averages after the experiment were 62.60 kg/mm², 54.92 kg/mm², 54.50 kg/mm², 51.31 kg/mm², and 49.37kg/mm² accordingly. Statistical analysis revealed that17% EDTA, BioAkt, 10% citric acid, and 40% citric acid decreased the dentin microhardness significantlycomparing with the negative control group, without statistical differences among them. Conclusion The chelating agents 17% EDTA, BioAkt, 10% citric acid, and 40% citric acid declined the microhardness of root canal dentin similarly, which might have possible effects on endodontic treatment and the properties of root canal filling materials as well.

Comparative Evaluation of the Effect of Different Endodontic Irrigation Protocols on the Microhardness of Root Canal Dentin: An In Vitro Study

Abstract Aim and Objective The present in vitro study was done to comparatively evaluate the effect of different endodontic irrigation protocols on the microhardness at coronal, middle, and apical levels of root canal dentin. Method The total sample size for the study was 100. Each sample consisted of a longitudinally sectioned half of a root of a single-rooted tooth, which was then embedded in acrylic resin. The prepared samples were divided randomly into five groups of twenty samples each. Each group was treated with its respective irrigant to be tested. Group I was the control—the specimens were treated with distilled water. The specimens in group II were treated with sodium hypochlorite (NaOCl), followed by ethylenediamine tetra-acetic acid (EDTA). Specimens in group III were treated with NaOCl, followed by CHX. Specimens in group IV were treated with NaOCl, followed by hydroxyethylidene bisphosphonate (HEBP), and specimens in group V were treated with NaOCl, followed by propolis. Following this, all the samples were placed on the Vickers microhardness tester, and the results were tabulated and statistically analyzed to determine the irrigant solutions' effect on the microhardness of root dentin at coronal, middle, and apical third. Results Intergroup comparison of various irrigants showed that 18% HEBP showed the least reduction in the microhardness values of root canal dentin, and 17% EDTA caused the maximum decrease in microhardness values with a significant difference. When the baseline values were compared with the values after the use of experimental solutions in all the groups, it was observed that the microhardness gradually decreased from coronal to apical third of root dentin. Conclusion On the basis of the results obtained, it can be concluded that weak chelators such as 18% HEBP do not affect the microhardness considerably, and that they can be used in future in place of strong chelators, that is, EDTA, which make root dentin weak by more microhardness reduction.

Comparative evaluation of Chloroquick with Triphala, Sodium hypochlorite, and EDTA on the microhardness of root canal dentin: an in vitro study

Comparative evaluation of Chloroquick with Triphala, Sodium hypochlorite, and EDTA on the microhardness of root canal dentin: an in vitro study

Influence of volume of endodontic irrigants used in different irrigation techniques on root canal dentin microhardness.

Overzealous application of endodontic irrigants affects the root canal dentin mechanical properties. The effect of volume of endodontic irrigants on the microhardness of root canal dentin has not been studied. This study assessed the effect of volume of endodontic irrigants used in different final irrigation activation techniques on root canal dentin microhardness (RCDM). Sixty human maxillary central incisors were embedded in acrylic resin in Kuttler's endodontic cube to the level of cementoenamel junction. The root samples were randomly divided into 4 experimental groups (n = 15): Group-NI-needle irrigation, Group-PUI-continuous passive ultrasonic irrigation, Group-EndoVac-apical negative pressure system, Group combination- EndoVac + PUI irrigation. Root canals were instrumented up to size 40 (F4). The resin mounted specimens were sectioned longitudinally into two halves and were reassembled in Kuttler's kube to carry out final irrigation activation. A predetermined standardized volume of irrigants was used in each group. The RCDM was measured after root canal instrumentation and after final irrigation using Vicker microhardness tester (coronal, middle, and apical third). The reduction in RCDM values (p < 0.0086) were analyzed using Kruskal Wallis and Mann Whitney-U tests. Reduction in RCDM was observed with all the endodontic irrigating techniques tested. EndoVac and combination irrigation techniques showed maximum reduction in RCDM in all thirds of root canal. It is concluded that the volume of irrigants and agitation plays a role in reducing RCDM. The overall volume of irrigants to cause maximum reduction was 25 ml, beyond which neither volume nor agitation affects RCDM.

Comparative evaluation of various chelating agents on the microhardness of root canal dentin: An in vitro study

Introduction: This study aims to compare and evaluate the effects of Irritrol and 17% ethylenediaminetetraacetic acid (EDTA) on the root dentin microhardness. Materials and Methods: A diamond disc was used to decoronate 15 human noncarious maxillary central incisors at the cemento‑enamel junction. Thirty root segments were set in an acrylic block with the dentinal surface exposed. All root segments were irrigated with sodium hypochlorite solution before treating with test solutions. Microhardness (Vickers hardness number [VHN]) values of each specimen were determined using Vickers indenter before and after treatment with test solutions (Irritrol and EDTA). The mean lengths of the two diagonals formed due to indentation were used to compute the microhardness value. VHNs were determined using these measurements. Mean differences between (Irritrol and EDTA) and within the (before and after) group were compared using Student’s t‑test. Intragroup comparison was done using F‑test (one‑way ANOVA) at different areas of radicular dentin. α =0.05 was the set level of significance. Results: Both the test solutions showed a reduction in microhardness in coronal and middle third of root canal dentin, but the reduction in apical third (P < 0.05) was significantly more with respect to EDTA when compared to Irritrol. Conclusion: Irrigation using 17% EDTA and Irritrol decreased the root dentin microhardness; however, in the apical third, there was a less decrease in microhardness by Irritrol when compared to EDTA.

Effect of different irrigation protocols and calcium hydroxide dressing on the microhardness of root canal dentin

Aim: This study aimed to evaluate the effect of different irrigation protocols and calcium hydroxide dressing on the microhardness of root canal dentin. Methodology: Thirty human teeth were decoronated and root segments were obtained from pre-established cuts made below the cemento-enamel junction. After specimen’s preparation, the initial dentin microhardness (H0) was measured with a Vickers indenter, on the coronal surface, at 150 µm and 500 µm from the root canal lumen. Next, the specimens were randomly distributed into three groups (n=10), according to the different irrigation protocols: 1% NaOCl; 1% NaOCl + 17% EDTA; and 5% NaOCl. After irrigation, the hardness measurement was repeated (H1), in another quadrant. Then, Ca(OH)2 dressing was applied and left for 30 days, until it was removed and a new microhardness measurement (H2) was made, in a third quadrant. The data were statistically analyzed using the three-way analysis of variance (ANOVA) and Tukey tests, set at α=0.05. Results: The factors analyzed (moment of VH, distance from the canal lumen and irrigation protocol) were statistically significant (p 0.05). The 5% NaOCl group shown the greatest difference between H0 and H1 measurements (p<0.05). Conclusions: All irrigation protocols promoted significant decrease of the dentin microhardness. The Ca(OH)2 dressing for 30 days did not significantly affect the microhardness of the root canal dentin.

Kitosan ve EDTA Solüsyonlarının Sonik ve Ultrasonik Sistemler ile Aktive Edilmesinin Dentin Mikrosertliğine Olan Etkisi

Objective: The aim of this in vitro study is to assess the effect of activation of EDTA and chitosan by different irrigation activation systems on the microhardness of root canal dentin. Material and Methods: A total of 60 single-rooted extracted mandibular premolars were prepared and randomly distributed into two groups (n=30) based on the final irrigant: Group 1, 0.2% chitosan; Group 2, 17% EDTA. Then, specimens of both groups were randomly divided into three subgroups (n=10) based on the irrigant activation; Subgroup A (Sonic), Subgroup B (Ultrasonic) and Subgroup C (Conventional irrigation, control group). The specimens (n=60) were embedded into resin blocks and sectioned horizontally 1 mm thick sections from 2,5 and 8 mm levels from the apex. All samples were used to determine the microhardness of dentin using a Vicker's microhardness tester. The data were analyzed using the three-way analysis of variance (ANOVA) and Tukey post-hoc tests to detect the effects of the independent variables (final irrigation solution, final irrigation techniques, and root canal thirds) on microhardness. Results: The three-way ANOVA indicated that chitosan exhibited a significantly lower microhardness value than EDTA (p<0.001). Also, regardless of the usage of final irrigation, both PUI and EA had significantly lower microhardness than CI (p<0.001). Conclusion: Chitosan as compared to EDTA (i), sonic (EA) and ultrasonic (PUI) final irrigation activation methods as compared to the traditional syringe method (CIS) (ii), apical and mid regions of the root as compared to its coronal region (iii), showed lower microhardness values.

Comparative Evaluation of Root Dentin Microhardness after using Different Standard Irrigating Solutions and Stevia Leaf Extract- An In vitro Study

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.

An in- vitro evaluation the effect of endodontic irrigation solutions on the microhardness of root canal dentin.

The aim of this study was to evaluate the effect of 5.25 sodium hypochlorite and17%EDTA on the microhardness of root canal dentin .Fifteen, maxillary incisor teeth extracted for periodontal reasons were used. Thecrowns of the teeth were removed at the CEJ. The roots were separated longitudinallyinto two segments, embedded in acrylic resin, and polished. A total of 30specimenswere divided into 3 groups of 10 teeth at random according to the irrigation solutionused: group 1: 5.25% NaOCl for 1min; group 2: 17% EDTA for 1 min; and group 3:distilled water (control). Each group was submitted to Vickers microhardnessindentation tests. The data were recorded as Vickers numbers and the results wereanalyzed statistically by using one-way ANOVA.The results showed that, irrigation with either sodium hypochlorite or EDTAdecreased the microhardness value of root dentin. Irrigation with EDTA gave morereduction of dentin compared to sodium hypochlorite. The reduction of VHN ofdentin following the irrigation treatment was statistically significant (p&lt; 0.05 ) .Both sodium hypochlorite and EDTA irrigation solution significantly reduced themicrohardness of root dentin..

EVALUATION OF THE MICROHARDNESS OF ROOT CANAL DENTIN AFTER DIFFERENT IRRIGATION PROTOCOLS (IN VITRO STUDY)

INTRODUCTION: Different irrigations solutions may cause alteration in the physicochemical properties of dentin structure thereby affecting the microhardness of root canal dentin. OBJECTIVES: to evaluate the effect of different irrigation protocols on microhardness of human root canal dentin. MATERIALS AND METHODS: Forty extracted single rooted lower premolars were used. All teeth were instrumented using manual stainless steel files and irrigated by 2ml distilled water between each file, then were sectioned by longitudinal splitting of each tooth. The root halves were randomly assigned into 4 parallel groups (n=10) and immersed for 5 minutes with one of the following irrigants: Group I: 10 ml of 2.5% Sodium Hypochlorite (NaOCL), Group II: 10 ml of 17% ethylene diamine tetra-acetic acid (EDTA) followed by 10 ml of 2.5% NaOCL, Group III: 10 ml of 2.5% NaOCL followed by 10 ml of 2% chlorhexidine digluconate (CHX), Group IV: 10 ml of 2.5% NaOCL followed by 10 ml distilled water then were followed by 10ml of 2% CHX. Ten root halves from each group were prepared to measure dentin microhardness at baseline measurement and after treatment to determine the change in microhardness, using Vickers tester. RESULTS: Data were analysed using t-test, ANOVA test and Post Hoc test.Group II showed the highest percentage decrease in microhardness values, followed by group III, then group IV and the lowest was group I. All groups showed a significant difference between each other (P < 0.05), except group III and IV. The coronal third showed the highest percentage decrease with significant difference between apical and middle thirds (P < 0.05), in which there was no significant difference between them. CONCLUSIONS: CHX is the best final irrigant if there is excellent intermediate flush for prevention of its precipitation with NaOCL.The coronal third needs conservative approach as it is the most affected third.

Effect of QMix 2 in 1, BioPure MTAD and 17% Ethylenediaminetetraacetic Acid on Microhardness of Root Canal Dentin: An in vitro Study

ABSTRACT Aim To compare the effect of QMix, a mixture of tetracycline, citric acid, and detergent (MTAD), and ethylenediaminetetracetic acid (EDTA) on the microhardness of the root canal dentin. Materials and methods A total of 30 single-rooted teeth were decoronated at 15 mm from the root apex. Root canal instrumen- tation using step back technique was done and the specimens were split into two halves using diamond disc. These were embedded in acrylic blocks and sent for testing by Vickers hard- ness test. The other half of the specimens was divided into four groups. Control group: In this, normal saline was used. Group I: MTAD was used. Group II: 17% EDTA was used. Group IV: QMix 2 in 1 (DENTSPLY) was used. The specimens were immersed in test irrigant for 5 minutes in closed glass plates. The tested specimens were sent for Vickers hardness test under 100 gm load for 15 seconds. The post Vickers hardness number readings were recorded and sent for statistical analysis. Results Data were analyzed using one-way analysis of variance and least significant difference post hoc test was applied for pairwise comparison. QMix showed significantly less reduction in microhardness than EDTA and QMix: Normal saline &gt; QMix&gt;EDTA&gt;MTAD. Conclusion QMix as a root canal irrigant is efficient as it caused least reduction of microhardness of dentin. It has antibacterial properties and is also efficient for smear layer removal. How to cite this article Gupta C, Singh G, Singh MP, Agarwal M, Singh KS, Mishra A. Effect of QMix 2 in 1, BioPure MTAD and 17% Ethylenediaminetetraacetic Acid on Microhardness of Root Canal Dentin: An in vitro Study. Int J Prosthodont Restor Dent 2017;7(1):17-20.

Effect of Herbal Alternative Irrigant (Green Tea Polyphenols) on the Microhardness of Root Canal Dentin after Instrumentation with Thermomechanically Treated NiTi Instruments: An in vitro Study

Effect of Herbal Alternative Irrigant (Green Tea Polyphenols) on the Microhardness of Root Canal Dentin after Instrumentation with Thermomechanically Treated NiTi Instruments: An in vitro Study

Effectiveness of Various Endodontic Irrigants on the Micro-Hardness of the Root Canal Dentin: An in vitro Study.

Irrigating solutions used for the elimination of micro-organisms during root canal preparation may affect the chemical and the physical properties of dentin thereby rendering the tooth more susceptible to fracture. Therefore careful and judicious selection of irrigant is required which have maximum benefits with minimum undesirable properties. The aim of the present study was to evaluate the effect of various endodontic irrigants on the micro-hardness of the root canal dentin. This in vitro study was carried out on eighty freshly extracted mandibular premolars with single canals. They were decoronated at the cemento-enamel junction. Roots were sectioned longitudinally into two halves. They were then polished and placed in autopolymerised resin moulds with the polished surface facing outside. The samples were divided into four groups based on the irrigants in which they were immersed i.e., 3% Sodium Hypochlorite (3% NaOCl), 17% Ethylene Dioxide Tetra Acetic Acid (17% EDTA), 0.2% Chitosan and 6% Morindacitrifolia Juice (MCJ) for 15 minutes each. All the specimens were then subjected to micro-hardness testing using a Vickers micro-hardness tester. Statistical analysis was done using one way Analysis of Variance (ANOVA), Post-Hoc Tukey test and Paired t-test to compare the pre and post immersion micro-hardness values of the selected samples. The results of the present study indicated that 17% EDTA and 0.2% Chitosan, significantly decreased the micro-hardness of root dentin whereas 6% MCJ and 3% NaOCl had no significant effect on the microhardness before and after immersing in the irrigants. A 6% MCJ and 3% NaOCl which have significant antibacterial, antifungal, anti-inflammatory and smear layer removing properties showed negligible effect on the micro-hardness of root canal dentin making them suitable endodontic irrigating solution.

EFFECT OF BIOPURE MTAD, SODIUM HYPOCHLORITE AND EDTA ON DENTIN MICROHARDNESS: IN VITRO STUDY

Objectives: The aim of this study was to evaluate the microhardness of root dentin wall before and after irrigation with BioPure MTAD, 17% Ethylenediamine tetra acetic acid (EDTA) and sodium hypochlorite (NaOCl).Study Design: Sixty-four freshly human extracted single-rooted teeth was used in this study. The teeth were divided into 4 groups, according to the irriganting solution used as final rinse: group (1) BioPure MTAD, group (2) 17% EDTA, group (3) 5.25% NaOCL and group (4) control group (distilled water). The teeth were sectioned longitudinally and prepared for evaluation of microhardness of root dentine before and after irrigation with each irrigants which the baseline microhardness testing was carried out using Vickers Microhardness Tester.Results: The results were statistically analyzed (p<0.05) showing significant difference between all the irriganting solutions in relation to the control group.Conclusion: The EDTA and BioPure MTAD drastically reduced the microhardness of root canal dentin followed by NaOCL.

Comparative Evaluation of Effect of Irrigation Solutions with Various Exposure Time on Microhardness of Root Canal Dentin (In Vitro Study)

Background: It is important to test the effect of the irrigating solutions on dentin, as they may come in contact during irrigation procedures. These irrigants cause alterations on dentin and enamel surfaces and affect their interactions with materials used for obturation and coronal restorations. The aim was to study the microhardness of root canal dentin after irrigation with different irrigant solutions for different periods. Materials and Methods: Twenty five newly extracted non carious human permanent incisors were sectioned at cementoenamel junction and splitted longitudinally then divided into five groups; Gr1 (control) distilled water, G2: 5.25% sodium hypochlorite (NaOCl) for (10 min) then 17% EDTA for (1 min), G3: 5.25% sodium hypochlorite (NaOCl) for (10 min) then 17% EDTA for (5 min), G4: 5.25% sodium hypochlorite(NaOCl) for (20 min) then 17% EDTA for (1 min) and G5: 5.25% sodium hypochlorite(NaOCl) for (20 min) then 17% EDTA for (5 min). Vickers microhardness was evaluated. Results: Data were analyzed using one-way ANOVA and paired t-test. The results indicated that all treatment time with 5.25% NaOCl and 17% EDTA decreased dentin microhardness significantly compared to distilled water (control). There were significant differences (P&lt;0.001) between the tested groups with increasing time of exposure of irrigation solutions. Treatment with distilled water (control) showed significantly the highest microhardness value, while 5.25% sodium hypochlorite for 20 minute followed by 5 minutes (G5) with 17% EDTA showed significantly the least microhardness value followed by G4, G3 and G2. Conclusions :Increasing irrigation time with both 5.25% sodium hypochlorite and 17% EDTA decreased dentin microhardness.

Impact of Chitosan as Chelating Agent on Microhardness and Mineral Content of Intraradicular Dentin

Aim: This study was designed to evaluate the effects of 0.2% chitosan, 2% chitosan and 17% EDTA chelating agents on the microhardness and mineral content of human root canal dentin. Materials and Methods: Sixty extracted single-rooted human teeth were longitudinally sectioned into 120 segments. The specimens were randomly divided into four groups according to the chelating agent used; G1: 0.2% chitosan, G2: 2% chitosan, G3: 17% EDTA and G4: saline (control group). Dentin microhardness was measured in a total of 80 specimens using Vickers diamond indenter with 300 g loadand a dwell time of 20 s. A total volume of 5 mL of each solution was used for 3min and then specimens finally flushed with 10 mL distilled water. In a total of 40 specimens, the level of three elements (calcium, phosphorus and magnesium) in each specimen was analyzed using inductively coupled plasma atomic emission spectrometry (ICPAES).Results: All tested chelating agents significantly decreased the microhardness of root canal dentin (P ≤ 0.05) and reduced the mineral content of dentin. Chitosan 2% and 17% EDTA had the statistically significant highest mean percentage reduction in microhardness compared to the control group (P ≤ 0.05) and showed the maximum loss of Ca ions from root canal dentin. Chitosan 0.2% showed less reduction in dentin microhardness and chelated Ca ions from root dentin. Conclusions: Chitosan 0.2% solution is equally effective to 17% EDTA in removing Ca ions from root canal dentin withoutmuch altering its microhardness. Accordingly, the natural product of 0.2% chitosan attracts its use as dentin chelating agent.

Effect of EDTA, Sodium Hypochlorite, and Chlorhexidine Gluconate with or without Surface Modifiers on Dentin Microhardness

IntroductionThis study aimed to evaluate the effects of root canal irrigants on the microhardness of root canal dentin in the presence and absence of surface-modifying agents. MethodsForty-eight root halves were prepared by longitudinal splitting of the distal roots of 24 freshly extracted mandibular human third molars and embedded in autopolymerizing acrylic resin, leaving the dentin surface exposed. After polishing, the microhardness values of the untreated dentin surfaces were recorded by using Vickers tester at the mid-root level. The root halves were randomly assigned to 6 groups composed of 8 samples each and treated for 5 minutes with one of the following irrigants: 17% EDTA, REDTA, 2% chlorhexidine gluconate (CHX), 2% CHX with surface modifiers (CHX-Plus), 6% NaOCl, or 6% NaOCl with surface modifiers (Chlor-XTRA). After surface treatment, dentin microhardness values were recorded at close proximity to the initial indentation areas. Experimental data were statistically analyzed by using the t test and one-way analysis of variance, followed by Tukey honestly significant difference test at α = 0.05. ResultsEDTA, REDTA, NaOCl, and Chlor-XTRA significantly decreased the microhardness of root dentin compared with intact controls (P < .05). ConclusionsThe addition of surface modifiers to the irrigants did not affect the microhardness of the samples.