Microhardness of root dentin depending on root canal treatment technique

To compare the effect of three different intracanal medicaments, namely, modified triple antibiotic paste (MTAP), calcium hydroxide (Ca(OH)2), and aloe vera, on the root dentine microhardness. A total of 50 extracted mandibular bicuspids were prepared using ProTaper Next rotary files. The roots of the bicuspids were alienated to three groups (n = 10 each) and one control group (untreated; n = 20). In three groups, the root canals were filled with MTAP, Ca(OH)2, and aloe vera medicaments. After 21 days, medicaments were removed by Endo activator. Mean Knoop hardness numbers were calculated after treatment and compared with the untreated control group. Data were evaluated using the Student's t test (paired), ANOVA (one-way) followed, and the post hoc test. All treated groups except the aloe vera group had shown significant reduction (p < 0.05) in microhardness of the root dentin as compared with the untreated control group. The aloe vera group showed least reduction of microhardness and was statistically insignificant (p > 0.05). Aloe vera shows promising results in terms of fewer effects on microhardness of the root dentin compared to MTAP and Ca(OH)2. Elimination of most of the bacterial infection from the root canal and very minimum to no effect on the microhardness of the dentin in the root part are the basics of success in any endodontic treatment. Further in vivo studies are required to compare the efficacy of these intracanal medicaments.

Aim: This in vitro study was carried out to compare of the effect of 17% ethylenediamine tetra-acetic acid (EDTA), 2% chlorhexidine (CHX), 18% etidronic acid (HEBP), and 4% propolis as an irrigant on the microhardness of root dentin. Materials and Methods: The sample size for the study was 100. Each specimen consisted of a longitudinally sectioned half of a root of a single-rooted tooth which was embedded in acrylic resin. The prepared specimens were divided randomly into five groups of twenty specimens each. Each group was treated with the irrigants 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 EDTA. Specimens in Group III were treated with NaOCl followed by CHX. Specimens in Group IV were treated with NaOCl followed by HEBP, and specimens in Group V were treated with NaOCl followed by propolis. Following this, all the specimens were placed on the Vickers hardness tester and three readings were taken for each specimen. An average reading was obtained for each group. The results were tabulated and statistically analyzed to determine which of the irrigant solutions had the least effect on the microhardness of root dentin. Results: Eighteen percent HEBP had the least effect on the root dentin microhardness, followed by 4% propolis and 2% CHX. Seventeen percent EDTA showed maximum effect on the microhardness of the dentin. Conclusion: Under the limitations of this study, 18% HEBP and 4% propolis show promise for use as irrigants because of less detrimental effect on the hardness of root dentin. More studies are needed on demineralization depth and the sealability of resin sealers in the radicular dentin after the use of propolis and HEBP.

ObjectivesTo evaluate the effects of three acids on the microhardness of set mineral trioxide aggregate (MTA) and root dentin, and cytotoxicity on murine macrophage.Materials and MethodsOrthoMTA (BioMTA) was mixed and packed into the human root dentin blocks of 1.5 mm diameter and 5 mm height. Four groups, each of ten roots, were exposed to 10% citric acid (CA), 5% glycolic acid (GA), 17% ethylenediaminetetraacetic acid (EDTA), and saline for five minutes after setting of the OrthoMTA. Vickers surface microhardness of set MTA and dentin was measured before and after exposure to solutions, and compared between groups using one-way ANOVA with Tukey test. The microhardness value of each group was analyzed using student t test. Acid-treated OrthoMTA and dentin was examined by scanning electron microscope (SEM). Cell viability of tested solutions was assessed using WST-8 assay and murine macrophage.ResultsThree test solutions reduced microhardness of dentin. 17% EDTA demonstrated severe dentinal erosion, significantly reduced the dentinal microhardness compared to 10% CA (p = 0.034) or 5% GA (p = 0.006). 10% CA or 5% GA significantly reduced the surface microhardness of set MTA compared to 17% EDTA and saline (p < 0.001). Acid-treated OrthoMTA demonstrated microporous structure with destruction of globular crystal. EDTA exhibited significantly more cellular toxicity than the other acidic solutions at diluted concentrations (0.2, 0.5, 1.0%).ConclusionsTested acidic solutions reduced microhardness of root dentin. Five minute's application of 10% CA and 5% GA significantly reduced the microhardness of set OrthoMTA with lower cellular cytotoxicity compared to 17% EDTA.

Purpose. To identify the stages of endodontic dental treatment that, according to a survey of dentists, can negativelyaffect the microhardness of root dentin.Material and methods. Seventy-seven dentists (24 men, 53 women) participated in the survey. Therapeuticmedical care was provided by 27 participants, mixed care – by 23 participants, therapeutic care with a predominanceof endodontic treatment – by 19 participants, pediatric consultations – by 8 participants. The average age of therespondents was 38 (24–70) years. The questionnaire was provided electronically via Google Forms. Statisticalanalysis of the contigency tables with Pearson’s chi-square test was carried out using the StatTech software (Russia).Results. Most respondents answered that mechanical root canal treatment impacts the microhardness of root dentinnegatively (88.7%). Younger dentists were significantly more likely to respond that activation of irrigation solutionnegatively affects the microhardness of root dentin compared with older physicians (p=0.008). Those specialistswho have encountered vertical crack of the root in lower premolars and in lower molars considered it necessary todevelop new approaches to endodontic treatment (p=0.036* for the lower premolars, р&lt;0.001* for the lower molars).Most dentists surveyed believe that temporary sealing pastes negatively affect the microhardness of root dentin,and it is necessary to develop new approaches to endodontic treatment, a smaller proportion did not consider thedevelopment of new approaches necessary and answered that temporary pastes affect microhardness (p=0.038).The opinion about the importance of maintaining the microhardness of root dentin to improve the prognosis duringrepeated endodontic treatment and the need to develop approaches for endodontic treatment was stated by asignificant number of respondents, compared with those who did not consider it important (p=0.007).Conclusions. The results of this survey showed a number of differences in the methods of endodontic treatmentused, opinions about the negative impact of certain treatment methods on the microhardness of root dentin, andthe importance of developing endodontic treatment approaches to preserve the microhardness of root dentin.Based on the survey results, reliable relationships between the stages and methods of work and their effect on themicrohardness of root dentin were revealed. Выявить этапы эндодонтического лечения зубов, которые по данным опроса врачей-стоматологов могут негативно влиять на микротвердость корневого дентина.Материал и методы. В опросе участвовали 77 врачей-стоматологов (24 мужчины, 53 женщины). Терапев-тический прием вели 27 человек, смешанный прием – 23 человека, терапевтический прием с преоблада-нием эндодонтического лечения – 19 человек, детский прием – 8 человек. Средний возраст респондентовсоставил 38 (24–70) лет. Анкету предоставляли в электронном виде Google Forms. Статистический анализтаблиц сопряженности проводили с помощью χ2-критерия Пирсона при помощи программы StatTech (Россия). Результаты. Данный опрос показал мнение респондентов: большинство опрошенных (88,7%) ответили, чтонегативный вклад в микротвердость корневого дентина вносит механическая обработка корневого канала.Врачи-стоматологи более молодого возраста достоверно отвечали, что активация ирригационного растворанегативно влияет на микротвердость корневого дентина, по сравнению с врачами более старшего возраста(p=0,008). Те врачи, которые сталкивались с вертикальной трещиной корня в нижних премолярах и в нижнихмолярах достоверно считают необходимым разрабатывать новые подходы к проведению эндодонтическоголечения (в нижних премолярах – p=0,036*, в нижних молярах – р&lt;0,001*). Большинство опрошенных врачей-стоматологов считают, что пасты для временного пломбирования негативно влияют на микротвердость корне-вого дентина и необходимо разрабатывать новые подходы к эндодонтическому лечению по сравнению с теми,кто не считает разработку новых подходов необходимым и что временные пасты влияют на микротвердость(p=0,038). Мнение о важности сохранения микротвердости корневого дентина для улучшения прогноза приповторном эндодонтическом лечении и необходимость разработки подходов к проведению эндодонтическоголечения выбрано большинством респондентов по сравнению с теми, кто не считает это важным (р=0,007). Заключение. Результаты данного анкетирования показали ряд различий в используемых методах эндо-донтического лечения, мнениях о негативном влиянии на микротвердость корневого дентина определенныхметодов лечения и важности разработки подходов к эндодонтическому лечению для сохранения микрот-вердости корневого дентина. На основании опроса были выявлены достоверные связи между этапами иметодами работы и их влияние на микротвердость корневого дентина.

Background The structural properties of dentin, including its microhardness, can be affected by exposure to endodontic irrigating solutions and ultrasonic activation. Aim The current study aimed to assess the effect of three different irrigation regimens, with and without ultrasonic activation, on the microhardness of the dentin. Methodology The research was conducted on 120 mandibular premolars randomly divided into four groups (n=30) based on the irrigation regimen, with each group further divided into two subgroups (n=15). Subgroups 'a" were subjected to respective irrigation regimens without ultrasonic activation. Subgroups 'b' were subjected to ultrasonic activation. The Vickers microhardness test was conducted on the samples, and the data underwent statistical analysis using the independent sample t-test, ANOVA, and the Tukey test. Results The observations of the study unveiled that the microhardness of the root dentin was decreased by all the irrigation regimens. Microhardness values of dentin showed higher reduction with ultrasonic activation than without ultrasonic for all groups. Conclusions The dentin microhardness was significantly reduced when 3% and 5% sodium hypochlorite were used with 17% ethylenediaminetetraacetic acid (EDTA) as irrigation solutions. Ultrasonic activation of the irrigants had an adverse effect on the microhardness of dentin.

Introduction:The use of bioactive glasses to re-establish or increase mechanical properties of the root dentin may be an interesting alternative. The aim of this study was to evaluate the effect of root repair materials and bioactive glasses on the microhardness of human root dentin. Methods and Materials:Sixty-four sectioned palatal roots of human molars were prepared and two slices were obtained of the middle third of each root (one corresponding to the control group, without treatment, and the other to the experimental group). The pairs of slices were randomly divided into four groups (n=16). The root canal of experimental slices were filled with one of the following materials: mineral trioxide aggregate (Angelus MTA, Angelus, Londrina, Paraná, Brazil), EndoSequence Root Repair Material (ERRM, Brassler, Savannah, GA, USA), Bioglass (45S5) and an experimental niobophosphate glass (NbG). The specimens were stored in an oven at 37ºC, in an environment with 100% humidity for 60 days. The specimens were subjected to a microhardness test. Four indentations were made at a distance of 20 µm from the root canal lumen. For microhardness analysis, comparing the experimental groups and their respective controls, the Student’s-t test was applied. For comparison of the percentage increase in microhardness between the groups, the data were statistically analyzed by using One-way ANOVA and Tukey’s test. The level of significance was set at 0.05. Results:All the materials significantly increased the dentin microhardness values (P<0.05). MTA showed a higher increase in microhardness (94.8±42.7%), similar to that of EndoSequence (62.3±39.9%). The 45S5 (46.5±30.0%) and NbG (53.8±31.3%) showed the lowest percentages of increase in microhardness, but were statistically similar to those of EndoSequence. Conclusion:All the materials tested were capable of increasing root dentin microhardness.

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.

Effect of endodontic irrigation solutions on microhardness of root canal dentine

Introduction: Disinfection of root canals can be done using intracanal irrigants. Sodium hypochlorite or NaOCL is amongst the most commonly used endodontic irrigants. Due to disadvantages of NaOCl, there is a need to identify a more biocompatible irrigant. Aim: To evaluate the antibacterial efficacy, depth of penetration into dentinal tubules and effect on microhardness of root dentin when NaOCl, Neem extract, Gau ark and Normal saline used as an irrigant against Enterococcus faecalis. Materials and Methods: Prepared Neem leaf extract, 3% NaOCl, Gau ark, Normal saline, Brain Heart Infusion (BHI) broth and BHI Agar were used in the present in-vitro study conducted from August-October 2019. Antimicrobial efficacy was measured by agar well diffusion method on 10 petriplates. After access opening and biomechanical preparation, each tooth sample was irrigated with 5 mL of irrigant. Samples were decoronated and roots were split along the longitudinal axis to check penetration depth of irrigants under stereomicroscope for 40 teeth samples. After preparation of 40 teeth sample, 2 mm dentin discs prepared were embedded in acrylic resin. Microhardness was checked under Vickers Microhardness (VHN) tester after samples were irrigated. Statistical Analysis of Variance and Tukey post-hoc test were used. Results: Zones of inhibition were highest with NaOCl (7.66 mm). Irrigants penetration depth into dentinal tubules was significant with NaOCl with average value 0.35 mm. Microhardness of root dentin of saline was 145.90 VHN, followed by Neem 136.59 VHN which was then followed by Gau ark 123.05 VHN hence, Neem has lesser effect on microhardness value as compared to NaOCl and Gau ark. There was statistically significant difference among four groups regarding antimicrobial efficacy, depth of penetration into dentinal tubules and microhardness of root dentin. Conclusion: Neem extract showed significant antimicrobial property as compared to Gau ark and normal saline, good penetration depth and less effect on microhardness of root dentin. Herbal irrigant like Neem extract can be used as a root canal irrigant.

Objective: To evaluate the chelating action of 17% EDTA and 10% citric acid on the root dentin microhardness. Method: Six human maxillary canines were used. The teeth were sectioned longitudinally and embedded in epoxy resin, thus providing 12 specimens that were divided in three groups: Group 1 – five specimens treated with 10% citric acid for 30 seconds; Group 2 – five specimens treated with 17% EDTA for 5 minutes; and Group 3 – control (no treatment with any chelating substance). Dentin microhardness was measured using a Vickers microhardness tester with load of 50 g for 15 seconds. Dentin microhardness was measured at the middle root third along the entire canal lumen extension up to the peripheral region close to the cementum. The dentin microhardness values were analyzed statistically by the Adherence test and Kruskal-Wallis test. Significance level was set at 5%. Results: Both chelating solutions affected significantly the root dentin microhardness, but the action of 17% EDTA was significantly greater than that of 10% citric acid. Conclusion: The 17% EDTA affects more the root microhardness than the 10% citric acid, when both chelating agents are used for the recommended clinical time. These results suggest that 10% citric acid for 30 seconds is the most indicated chelating solution for use in endodontic therapy because it removes the smear layer effectively and affects less the root dentin microhardness.

Aims: To measure the microhardness of root canal dentin using two types of irrigating solutions( 0.2% Chlorhexidine and 5.25% Sodium Hypochlorite) with and with out use of different types of root canal files (Stainless Steel-K files, Nickel-Titanium K-files or rotary Nickel-Titanium files). Materials & methods: The teeth divided in to four groups according to the type of irrigating solutions that used during root canal instrumentation with the use of normal saline as a control group, then each group sub divided in groups according to the instrument used in the root canal preparation, then after irrigation and preparation the roots sliced and root dentin microhardness measured using Vicker,s microhardness machine. Results: The result of this study showed that the type of instrument and Chlorhexidine have no effect on the microhardness of root canal dentin while Sodium Hypochlorite significantly decrease the microhardness of root canal dentin especially when use with Stainless Steel K-files and Nickel-Titanium K-files than when used with rotary Nickel-Titanium files. Conclusion: The microhardness of root canal dentin not affected by the type of root canal instruments.,The use of 5.25% Sodium Hypoch-lorite as a root canal irrigation significantly reduce the microhardness of root dentin within 3 mi-nutes., The use of Sodium Hypochlorite as a root canal irrigant with stainless steel K-files or Nickel-Titanium K-files reduce the microhardness of root canal dentin to greater extend than when use with rotary Nickel-Titanium files because the working time required with Stainless Steel K-files or Nickel-Titanium K-files was on the average three times longer than the working time with rotary Nickel-Titanium files. The use of sodium hypochlorite as a root canal irrigant with stainless steel K-files or Nickel-Titanium K-files reduce the microhardness of root canal dentin

The Effect of Surfactant Addition to EDTA on Microhardness of Root Dentin

The use of intracanal medicaments (ICM) is crucial toreduce the microbial load in root canals. However, its application may negatively affect the physical properties of root dentine. Thus, this in vitro study was performed to investigate the effects of different herbalICM on the microhardness ofroot dentin. A total of 100 mid-root discs were randomly divided into five groups (n = 20) and treated with Aloe vera, Aloe vera + chitosan, curcumin, curcumin + chitosan, and control for 14 days. A Vickers hardness indentation machine (Laizhou Laihua Testing Instrument Factory, Yantai, China) with a load of 200 g and a dwell time of 15 seconds was used for microhardness testing before andafter treatment. The results were analyzed usingStatistical Product and Service Solutions (SPSS, version 26.0; IBM SPSS Statistics for Windows, Armonk, NY). Intragroup comparisons were executed using paired t-tests, while intergroup comparisons employed ANOVA, followed by post-hoc Tukey's tests. The Aloe vera + chitosan and curcumin + chitosan groups showed a statistically significant reduction in dentin microhardness (p < 0.05). The decrease in dentin microhardness ofthe Aloe vera and curcumin groups was non-significant (p > 0.05) and similar to that of the control. Aloe vera or curcumin alone as ICM did not affect the root dentin microhardness. The addition of0.2% chitosan to either Aloe vera or curcumin negatively affected the root dentin microhardness.

ABSTRACTAim: To evaluate and compare the antibacterial efficacy of turmeric extract as an intracanal medicament against E. faecalis and its effect on the microhardness of root dentin in comparison with calcium hydroxide and 2% chlorhexidine gel.Materials and methods: One hundred and fourty dentin blocks were prepared from 70 extracted human single-rooted teeth and standardized. For antibacterial assessment, 120 blocks were infected for 21 days with E. faecalis (n = 24/group). Dentin blocks were treated with group I (Ca(OH)2), group II (2% chlorhexidine gel), group III (turmeric extract), group IV (saline) and group V (negative control). Dentin shavings were obtained in TSB at depth of 400 μm and plated to count CFUs at 24 hours, 3 and 7 days (n = 8/day). For microhardness assessment, eight samples of 2 mm thickness were prepared form four dentin blocks (n = 8/group). Following treatment with medicaments, microhardness test was performed at 24 hours, 3 and 7 days using Vickers hardness indentation machine at 400 μm from canal lumen.Results: Complete inhibition of E. faecalis was observed with group II, followed by 64% with group I and 54% with group III which was statistically highly significant (p < 0.001). Highest effect on microhardness of root dentin was shown by group I, followed by group II and no effect was seen with group III which was statistically highly significant (p < 0.001).Conclusion: Turmeric extract has substantial antibacterial activity with no effect on microhardness of root dentine and hence has a potential to be used as intracanal medicament if its antibacterial activity could be enhanced.How to cite this article: Prabhakar AR, Swapnil T, Savita H, Sugandhan S. Comparison of Antibacterial Efficacy of Calcium Hydroxide Paste, 2% Chlorhexidine Gel and Turmeric Extract as an Intracanal Medicament and their Effect on Microhardness of Root Dentin: An in vitro Study. Int J Clin Pediatr Dent 2013;6(2):171-177.

To evaluate the effects of Er:YAG laser combined with NaClO on the removal of root canal taint layer, calcium hydroxide clearance and dentin microhardness. A total of 318 single-rooted extracted teeth collected from March 2021 to January 2024 were selected, the 13 mm root was taken and mechanically prepared and randomly divided into three groups, with 106 teeth in each group. The control group was rinsed with NaClO, the experimental group 1 was rinsed with NaClO combined with ultrasonic washing, and the experimental group 2 was treated with Er:YAG laser on the basis of NaClO. The removal of the smear layer was observed under electron microscope, and the microhardness of dentin post-treatment was assessed using a microhardness tester. The clearance rate of calcium hydroxide in experimental group 2 was significantly higher than that in experimental group 1 and control group, and the stain layer scores of crown formula 1/3, root middle 1/3 and root tip 1/3 were significantly lower than those in the other 2 groups(P＜0.05). There was no significant difference between the initial and final microhardness of the three groups(P＞0.05). Er: YAG laser combined with NaClO can effectively enhance the removal effect of stain layer in root canal therapy, and has little effect on dentin microhardness.