The evaluation of dentin microhardness after use of 17% EDTA, 17% EGTA, 10% citric acid, MTAD used as chelating agents combined with 2.5% sodium hypochlorite after rotary instrumentation: An in vitro SEM study

Abstract

Introduction: The smear layer removed during root canal instrumentation enables penetration of irrigant solution and adhesion of root canal sealants providing a fluid tight seal of obturated root canals, necessitating its removal. The aim of the study was to compare the effect of smear layer removal by 17% Ethylene diamine tetraacetic acid (EDTA), 17% Ethylene glycol tetraacetic acid (EGTA),10% Citric acid and (MTAD solution) a Mixture of tetracycline isomer, an acid and a detergent applied as final rinse , when used along with 2.5% (NaOCl) Sodium hypochlorite and its effect on dentin microhardness. Materials and Methods: Sixty single-rooted human mandibular premolars with minimum curvature (<5°) were instrumented using rotary instrumentation till apical enlargement size 35 RaCe file 0.04 taper. During instrumentation, the canals were irrigated with 2-mL 2.5% NaOCl. After instrumentation, teeth were rinsed with distilled water and were divided into 5 groups ( n = 12) according to final rinse for 1 min with 5-mL 17% EDTA followed by 5-mL 2.5% NaOCl (group 1, control group), 17% EGTA (group 2), MTAD solution (group 3), 10% citric acid (group 4), and 17% EDTA (group 5). Teeth were split through the groove prepared, and one-half of specimen were evaluated for smear layer removal using scanning electron microscopy. A score system was followed to evaluate the images and comparisons among groups were performed using Kruskal–Wallis one-way analysis. Multiple comparisons were performed using Mann–Whitney U test. The other half was evaluated for dentin microhardness using Vickers microhardness testing machine. Microhardness values were statistically analyzed using parametric one-way analysis of variance test. Conclusion: Irrigation regimen following the use of 2.5% NaOCl during instrumentation followed by application of 5-mL 17% EDTA solution for 1 min resulted in efficient smear layer removal and less decrease in dentin microhardness compared with 17% EGTA, 10% citric acid, and MTAD solution.

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

“…Bahgwat et al (23) found that microhardness of dentin was most affected by EDTA in comparison to 4% propolis and 18% etidronic acid (HEBP). UnniKrishnan et al (24) found that EDTA+NaOCL group decreased microhardness much more in comparison to 10% citric acid, 17% Ethylene glycol tetraacetic aacid (EGTA) and MTAD solution.…”

The effect of intracanal medication variations on microhardness of simulated immature root dentin

“…These results may be due to the use of abundant irrigation solutions and medicaments. The effects of irrigation solutions on dentin roughness, microhardness and flexural strength (10)(11)(12)(13) as well as the effects of the most common root canal medicaments such as CH and TAP (17)(18)(19)(20)(21)(22) have been reported several times. Although the literature on the positive correlation between microhardness change and fracture resistance is limited, longer exposure to chelating agents (31) and medicaments (17,21) has been reported to reduce the microhardness and fracture resistance of endodontically treated teeth.…”

“…EDTA is a chelating agent for inorganic di-covalent cations, and when applied to dentin, it may affect the calcium and phosphorus ratio, resulting in a decrease in microhardness (10)(11)(12). Furthermore, due to its organic tissue dissolving effect, it has been reported that dentin microhardness decreases after exposure to NaOCl (12,13). In recent years, the use of phytic acid (PA) has been proposed as an alternative to EDTA (10,(14)(15)(16).…”

“…Although root dentin thickening and root lengthening have been reported in many studies (3)(4)(5)(6), clinicians continue to report horizontal fractures in teeth treated with regenerative procedures (25,26). Considering the data reported about the effects of root canal irrigants and root canal medicaments on microhardness reduction (10)(11)(12)(13)(17)(18)(19)(20)(21)(22) and fracture resistance (17,27), the aim of this study was to evaluate the effect of different irrigation solutions and different intracanal medicaments used in regenerative endodontic treatments on the microhardness of the root dentin depending on time. The null hypothesis of this study was that neither intracanal medicaments nor irrigation solutions would alter the microhardness of root dentin over time.…”

Triphala in Endodontics-A Review

“…The amount of hydroxyapatite in the intertubular substance and the degree of mineral content assist determine the intrinsic hardness properties of dentin structure. As a result, a decrease in dentin microhardness leads to an increase incidence of crack formation and tooth fractures [43,44].…”