Nidambur Vasudev Ballal

Comparison of the Efficacy of Maleic Acid and Ethylenediaminetetraacetic Acid in Smear Layer Removal from Instrumented Human Root Canal: A Scanning Electron Microscopic Study

INTRODUCTION The aim of this study was to assess, by scanning electron microscopic (SEM) analysis, the ability of 17% EDTA and 7% maleic acid in the removal of the smear layer from the human root canal system. METHODS Eighty single-rooted human anterior teeth were subjected to standardized root canal instrumentation (step-back technique) and were irrigated with 2.5% NaOCl after each instrument. Based on the final irrigating solution used, samples were divided randomly into three groups: (1) the EDTA group: 17% EDTA+ 2.5% NaOCl (n = 30), (2) the maleic acid group: 7% maleic acid + 2.5% NaOCl (n = 30), and (3) the control group: 0.9% saline (n = 20). After final irrigation, teeth were prepared for SEM analysis to evaluate the cleaning of the coronal, middle, and apical thirds of radicular dentin by determining the presence or absence of smear layer. The data was statistically analyzed using the Kruskall-Wallis test. RESULTS At the coronal and middle thirds, there was no significant difference between EDTA and maleic acid. Both were equally efficient in the removal of smear layer. In the apical third, maleic acid showed significantly better smear layer removing ability than EDTA. CONCLUSION Final irrigation with 7% maleic acid is more efficient than 17%EDTA in the removal of smear layer from the apical third of the root canal system, which is a crucial area for disinfection.

Evaluation of the Effect of Maleic Acid and Ethylenediaminetetraacetic Acid on the Microhardness and Surface Roughness of Human Root Canal Dentin

INTRODUCTION The aim of this in vitro study was to evaluate the effect of 7% maleic acid and 17% EDTA solutions on the microhardness and the surface roughness of human root canal dentin. METHODS Forty-five extracted human maxillary central incisors were sectioned longitudinally into a total of 90 segments, were embedded in auto polymerizing acrylic resin, and were grounded flat with silicon carbide abrasive papers. Based on the test solutions used, samples were divided randomly into three groups: (1) the EDTA group, 1 mL of 17% EDTA for 1 minute (n = 30), (2) the maleic acid group, 1 mL of 7% maleic acid for 1 minute (n = 30), and (3) the control group, 1 mL of 0.9% saline for 1 minute (n = 30). Every group was then divided into two subgroups of 15 specimens each. In group 1a, 2a, and 3a, specimens were used to determine the microhardness of the root canal dentine in the coronal, middle, and apical third using Vickers hardness tester. In groups 1b, 2b, and 3b, specimens were used for the determination of surface roughness of the root canal dentine using a roughness tester (Surtronic, Leicester, England). The data were statistically analyzed using the Kruskall Wallis and Mann Whitney U tests. RESULTS There was no significant difference between EDTA and maleic acid in the reduction of microhardness. The increase in roughness was significantly greater with maleic acid when compared with EDTA. CONCLUSION Maleic acid reduced the microhardness of root dentin similar to EDTA but increased the surface roughness significantly more than EDTA.

In Vitro Sustained Release of Calcium Ions and pH Maintenance from Different Vehicles Containing Calcium Hydroxide

INTRODUCTION Calcium hydroxide is widely used as an intracanal medicament in endodontics. Its therapeutic effects depend on the dissociation of calcium hydroxide into calcium and hydroxyl ions, which, in turn, depends on the vehicle used. The purpose of this in vitro study was to evaluate the sustained release of calcium ions and the pH change of calcium hydroxide over a period of 30 days when formulated with propylene glycol, polyethylene glycol 6000, chitosan, and guar gum. METHODS Various formulations were prepared and placed inside the root canals of human teeth and were suspended in glass vials containing distilled water. At specific time intervals, the calcium ion concentration was analyzed using an ultraviolet spectrophotometer. pH changes of the medium were measured at various time intervals up to 30 days. RESULTS Results revealed that chitosan formulation showed the maximum sustained release of calcium ions compared with the other three formulations. All the formulations exhibited high alkaline pH upto 30 days. CONCLUSION From the results of this in vitro study, it can be concluded that chitosan can be used as a promising vehicle for for the sustained release of calcium ions from the calcium hydroxide in the root canal system.

Wettability of root canal sealers on intraradicular dentine treated with different irrigating solutions

OBJECTIVES The aim of this in vitro study was to evaluate the wettability of AH Plus and ThermaSeal Plus sealers on intraradicular dentine treated with different irrigating solutions. METHODS Fifty anterior teeth were decoronated and split longitudinally. Each root half was divided into 5 groups (n=10). Group I: 5mL of 2.5% NaOCl+QMix. Group II: 5mL of 2.5% NaOCl+17% EDTA. Group III: 5mL of 2.5% NaOCl+7% maleic acid. Group IV: 5mL of 2.5% NaOCl. Group V: 5mL of distilled water. Irrigation regimens were performed for 1min. Each specimen was placed inside a Dynamic Contact Angle Analyser. A controlled-volume droplet of sealer was placed on each specimen and the static contact angle was analysed. RESULTS The contact angle made by both sealers with EDTA-irrigated dentine was significantly larger when compared to the other irrigants (P<0.05). For ThermaSeal Plus, contact angles produced on maleic acid-, NaOCl- and distilled water-irrigated dentine were not significantly different, but were all significantly larger than the contact angle produced on QMix-irrigated dentine (P<0.05). For AH Plus, contact angles produced on NaOCl- and distilled water-irrigated dentine were not significantly different, but were significantly larger than those made by maleic acid and QMix. CONCLUSION When used as a final irrigant, QMix favours the wetting of root canal dentine by both AH Plus and ThermaSeal Plus sealers. Maleic acid shows a promising result when compared to EDTA and NaOCl. Wettability of both sealers is the worst on EDTA-irrigated dentine. CLINICAL SIGNIFICANCE The present study highlights the effect of newer endodontic irrigating solutions on the wettability of sealers on to the root canal dentine, which is required for obtaining good obturation seal.

Evaluation of Chemical Interactions of Maleic acid with Sodium Hypochlorite and Chlorhexidine gluconate

INTRODUCTION The elimination of microorganisms from the root canal system necessitates the use of combination of irrigating solutions to enhance their antimicrobial property. The combination of irrigants and their interaction sometimes could be detrimental to the outcome of the root canal therapy. The purposes of this study were (1) to evaluate the interaction between 7% maleic acid (MA) and 2% chlorhexidine gluconate solution (CHX) and to find out the availability of individual irrigant and (2) to determine the free available chlorine content when 7% MA was mixed with 2.5% sodium hypochlorite (NaOCl) solution. METHODS Interaction between MA and CHX was assessed by high-performance liquid chromatography. Available chlorine content in NaOCl was evaluated by the standard iodine/thiosulfate titration method. RESULTS It was observed that more than 90% free MA and CHX were available when MA was combined with CHX. It was also observed that there was no precipitate formation when 7% MA was mixed with 2% CHX. Available chlorine content decreased significantly in the MA/NaOCl mixture. CONCLUSIONS There were no adverse interactions or precipitate formation observed when MA was combined with CHX, but the available chlorine content was reduced when NaOCl was mixed with MA.

Evaluation of decalcifying effect of maleic acid and EDTA on root canal dentin using energy dispersive spectrometer

OBJECTIVE The aim of this study was to evaluate mineral contents of root canal dentin after treatment with 7% maleic acid (MA) or 17% EDTA. STUDY DESIGN Thirty pieces of teeth were divided into 3 groups: 1) 17% EDTA; 2) 7% MA; and 3) saline. All specimens were treated for 0, 1, 5, 10, 15 minutes. Levels of calcium, phosphorus, magnesium, sodium, sulfur, and oxygen were measured using energy dispersive spectrometer. Data were analyzed using 1-way analysis of variance. Tukey honest significant difference and Bonferroni test were used for comparison between the groups and time periods. RESULTS MA reduced maximum amount of calcium and phosphorus at all time intervals, but was significant only up to 5 minutes (P < .001). Oxygen, sulfur, and magnesium were decreased more with saline and least with MA (P < .001). Sodium was decreased more with MA and least with EDTA (P < .001). CONCLUSIONS MA decalcifies the root dentin, with most calcium and phosphorus extracted during the first 5 minutes, compared with EDTA.

Comparative Evaluation of Accuracy of 2 Electronic Apex Locators with Conventional Radiography: An Ex vivo Study

INTRODUCTION The aim of this ex vivo study was to evaluate the accuracy of the Raypex 5 (VDW, Munich, Germany) and Apex NRG XFR (Medic NRG Ltd, Tel Aviv, Israel) electronic apex locators (EALs) in determining the working length when compared with radiographs. METHODS Twenty-five human single-rooted teeth were selected, and the access cavity was prepared. The working length (WL) was determined radiographically and electronically by using 2 EALs. The files were fixed at the WL, and the teeth were extracted. The apical 4 mm of each canal was trimmed to expose the file tip, and the samples were observed under a stereomicroscope. The distance from the file tip to the point 0.5 mm coronal to the anatomic apex was measured. The data were analyzed by using 1-way analysis of variance and the Tukey Honestly Significant Difference test. RESULTS There was no significant difference between the Raypex 5 and the Apex NRG XFR devices with respect to their accuracy in determining the final WL. When compared with radiography, both the EALs had no significant difference. When comparing EALs and radiographic measurements with control measurements, accuracy results were found to be 20%, 36%, and 52% for the Raypex 5, Apex NRG XFR, and radiography, respectively. Overestimations of WL determination by the Raypex 5, Apex NRG XFR, and radiography were 4%, 0%, and 40%, respectively. Underestimations of WL determination by the Raypex 5, Apex NRG XFR, and radiography were 76%, 64%, and 8%, respectively. CONCLUSIONS Both the EALs had the same accuracy in determining the WL when compared with radiography.

A comparative evaluation of postobturation apical seal following intracanal irrigation with maleic acid and EDTA: a dye leakage under vacuum study.

OBJECTIVE The aim of the study was to evaluate the postobturation apical seal following irrigation with 7% maleic acid (MA) or 17% EDTA using dye leakage under vacuum method. STUDY DESIGN Seventy single-rooted human anterior teeth were subjected to root canal instrumentation. Based on the final irrigating solution used, samples were divided into 3 groups: (1) 17% EDTA + 2.5% NaOCl, (2) 7% MA + 2.5% NaOCl, (3) 0.9% saline. Then samples were obturated and placed in 2% rhodamine B dye solution under vacuum pressure for 30 minutes and allowed to remain in the dye for 7 days. Samples were then longitudinally split and examined for dye leakage under stereomicroscope. Data were analyzed using the Kruskal-Wallis test. RESULTS MA showed the least apical leakage compared with EDTA and saline. Saline showed maximum leakage. CONCLUSION Final irrigation with 7% MA improved the postobturation apical seal compared with 17% EDTA.

In vitro antimicrobial activity of maleic acid and ethylenediaminetetraacetic acid on endodontic pathogens

OBJECTIVE The aim of this study was to evaluate the antimicrobial efficacy of 7% maleic acid (MA) and 17% ethylenediaminetetraacetic acid (EDTA) in elimination of Enterococcus faecalis, Candida albicans, and Staphylococcus aureus at different time intervals. STUDY DESIGN Transfer culture of microbial strains were used for inoculum preparation and determination of time-kill assay. The viability counts of 7% MA and 17% EDTA suspensions were performed at 0, 2, 4, 6, 12, and 24 hours. Assay results were analyzed by determining number of strains that yielded log(10) CFU/mL of -1 compared with counts at 0 hours, for test medicaments at time intervals. Medicaments were considered to be microbicidal at a minimum inhibitory concentration that reduced original inoculum by >3 log(10) CFU/mL (99.9%) and microbiostatic if inoculum was reduced by <3 log(10) CFU/mL. Statistical analysis was performed using chi-square and Fisher exact tests as well as Friedman test for comparison of the time interval within the MA and EDTA groups. RESULTS At all time intervals, there was no significant difference between MA and EDTA for all of the organisms (P > .05). However, within the MA and EDTA groups at various time intervals, there were significant differences (P < .001). CONCLUSIONS Equivalent antimicrobial activity was observed by MA and EDTA against all of the organisms tested at various periods.

Effect of maleic acid and ethylenediaminetetraacetic acid on the dissolution of human pulp tissue--an in vitro study.

AIM To compare in vitro, the tissue-dissolution capacity of 7% maleic acid (MA), 17% ethylenediaminetetraacetic acid (EDTA), 2.5% sodium hypochlorite (NaOCl) (positive control) and 0.9% saline (NaCl) (negative control) on human pulp tissue. METHODOLOGY Forty pieces of human pulp tissue, each weighing 0.026 g, were divided randomly into four groups (n = 10): (i) 7% MA solution, (ii) 17% EDTA solution, (iii) 2.5% NaOCl solution and (iv) 0.9% NaCl solution. The pulp tissue was placed in beakers containing the test solutions and then placed on a vibrator. Pulp tissue from the four experimental solutions was blotted dry and weighed after 30, 60, 90 and 120 min. The percentage of weight loss was calculated, and the data were statistically analysed using Kruskal-Wallis and Mann-Whitney U-test. RESULTS At all time intervals, 2.5% NaOCl dissolved pulp tissue significantly more than the other solutions (P < 0.001). There was no significant difference in the pulp-dissolution capacity between 7% MA and 17% EDTA at any of the time intervals. NaCl (0.9%) did not have any effect on pulp tissue. CONCLUSION Seven percentage of MA and 17% EDTA had minimal tissue-dissolution capacity when compared to NaOCl.