Aim:The purpose of this study was to evaluate the effect of phytic acid, ethylenediaminetetraacetic acid (EDTA), and chitosan solutions on the microhardness of human radicular dentin.Materials and Methods:Thirty dentin specimens were randomly divided into three groups of 10 specimens each according to the irrigant used: G1 — 1% phytic acid, G2 — 17% EDTA, and G3 — 0.2% chitosan. A standardized volume of each chelating solution was used for 3 min. Dentin microhardness was measured before and after application at the cervical, middle, and apical levels with a Vickers indenter under a 200-g load and a 10-s dwell time. The results were analyzed using one-way analysis of variance (ANOVA) and Student's t test.Results:Microhardness of the radicular dentin varied at the cervical, middle, and apical levels. EDTA had the greatest overall effect, causing a sharp percentage reduction in dentin microhardness with a significant difference from phytic acid and chitosan (P = 0.002). However, phytic acid and chitosan differed insignificantly from each other (P = 0.887).Conclusion:All tested chelating solutions reduced microhardness of the radicular dentin layer at all the levels. However, reduction was least at the apical level. EDTA caused more reduction in dentin microhardness than chitosan while phytic acid reduced the least.

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Aim:The aim of this study is to evaluate the marginal sealing ability of self-adhesive flowable composite resin when used as a liner in Class II composite restoration with and without aging.Materials and Methods:A total of 120 standardized Class II tooth preparations with gingival margins 1 mm coronal and apical to cementenamel junction (CEJ) were prepared on 60 extracted permanent mandibular molars and were randomly divided into eight equal Groups: Group 1: cavities coronal to CEJ and restored with Dyad flow liner + Herculite ultra, Group 2: same as Group 1 but cavities margins apical to CEJ, Group 5: cavities coronal to CEJ and restored with only Herculite ultra, and Group 6: same as Group 5 but cavities apical to CEJ. Groups 3,4,7,8 were similar to Groups 1,2,5,6, respectively, but were aged for 6 months. After thermocycling, microleakage testing was done using 0.5% basic fuchsin dye.Result:At cervical level, Group 5 exhibited statistically lower (P = 0.006) microleakage than Group 6, and Group 1 showed lesser microleakage than Group 5 (P = 0.162). Group 2 exhibited significantly less microleakage than Group 6 (P = 0.002). Increased microleakage was observed in aging Groups; however, the difference with nonaging Groups was not statistically significant (P > 0.005).Conclusion:Margins of the cavity in cementum can be better sealed by placing self-adhesive liner and is not affected by aging.

Context: Extracanal and intracanal heating of sodium hypochlorite (NaOCl) improve its pulp dissolution, but limited literature is available on its effect as a combined single irrigant with etidronate. Aim: The aim of this study is to compare the effect of temperature on the effectiveness of NaOCl and continuous chelation protocol on the time required for the dissolution of vital and necrotic pulp. Materials and Methods: Dissolution time of 120 standardized bovine (buffalo) pulp fragments, divided into 12 subgroups based on tissue type (vital/necrotic), irrigant (NaOCl/continuous chelation), and temperature (extracanal, intracanal, and nonheated irrigant), was noted. Conical glass tips mimicking the root canal were considered specimen containers. About 0.2 ml of irrigant corresponding to the irrigation protocol was taken in them and then pulp samples were added to it. Samples were observed using loupes under 2.5 X magnification. Dissolution time was recorded using a stopwatch. The study was approved by the Institutional Ethical Committee (SDC/2019/591). Statistical Analysis Used: Two-way analysis of variance; statistical product and service solutions version 25. The level of significance was set at P < 0.05. Results: Time for pulp dissolution by continuous chelation mixture was significantly more as compared to NaOCl alone in all subgroups. Pulp tissue dissolution for both vital and necrotic pulp was improved by the increase in temperature of both irrigants and dissolution time was more for necrotic than vital tissue. Pulp tissue dissolution was significantly better by intracanal heating as compared to extracanal heating. Conclusion: Although intracanal heating of continuous chelation mixture improves its pulp dissolution capacity significantly as compared to extracanal heating and nonheating protocol but pulpal dissolution capacity of nonheated 5% NaOCl still remains significantly better as compared to intracanal and extracanal heated continuous chelation mixture.

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