Background: This study aimed to compare the apical seal in teeth treated with gutta-percha and Bio-C Sealer, Endoseal TCS Sealer, and AH Plus Sealer using the single-cone technique. Methods: In this experimental study, 56 single-rooted, single-canal mandibular premolars were prepared using the Protaper rotary system. The samples were randomly divided into three groups of 16 and two positive and negative control groups and were obturated with Bio-C Sealer, Endoseal TCS Sealer, and AH Plus Sealer using the single-cone technique. The samples were divided into buccal and lingual halves using a diamond disc. The linear leakage of methylene blue from the root apex to the coronal- most part where the dye penetrated was observed and recorded using a stereomicroscope, and finally the data obtained were analyzed using one-way analysis of variance between groups with SPSS version 26 software. Results: The results of the study showed that the lowest dye penetration rate in the Sealers studied was for Endoseal TCS Sealer (4.16±0.475), AH Plus (4.84±0.745), and Bio-C Sealer (5.77±0.597). The results of the analysis of variance showed that there was a significant difference in apical microleakage in teeth treated with gutta-percha and Bio-C Sealer, Endoseal TCS Sealer, and AH Plus Sealer by the single-cone technique (p<0.001). Tukey's test showed that there was a significant difference in apical microleakage of the Sealers studied with the positive and negative control groups; also, a significant difference was observed in apical microleakage of Endoseal TCS Sealer with Bio-C Sealer and AH Plus Sealer, and Bio-C Sealer with AH Plus Sealer (p<0.05). Conclusion: Apical sealing in root canal–treated teeth with gutta-percha and Endoseal TCS Sealer provided the best results compared to AH Plus and Bio-C Sealer.

Statement of problem: Studies have shown the effect of Sealers used with master cones in order to gain better apical multi dimensional sealing. This goal is considered to be effective in treatment prognosis and blocking micro-organisms and limiting their activities. Applicable Sealers should have advantages such as little dissolution and proper adaptation to periapical tissue. Calcium phosphate and hydroxyapatite are compounds that have shown significant effect in recovery of osseous lesions.Purpose: The aim of this study was to apply a mixture of these materials as Sealer, named Apatite Root Sealer, with gutta percha in root canals and compare its micro leakage with AH26 Sealer.Materials and method: In this experimental study 26 extracted single-root human adult teeth, with same size and without curve were selected. The apical third of roots were prepared by step-back technique and Race rotary files (6%) up to MAF# 40 and the coronal two thirds were prepared by gates gliddens. The canals were irrigated with sodium hypochlorite 5.25%. The teeth were divided in two test groups of 10 and two control groups of three teeth. Group A: Canals were filled with gutta percha & Apatite Root Sealer. Group B: Canals were filled with gutta percha & AH26 Sealer.The access cavities were sealed with Glass ionomer and then samples were placed in incubator at 37°C and 100% humidity for about 48 hours. After sealing the roots with two layers of nail polish and sticky wax except for the two mm of apical area, the teeth were placed in silver nitrate 50% for six hours and then rinsed and exposed to florescent light before floating in developing solution for about two hours. Specimens were sectioned longitudinally from buccal to lingual and examined under a stereomicroscope by 0.1 mm accuracy. The dye penetration level was measured and analyzed using T-student statistical test.Results: Measuring the samples showed that dye penetration in Apatite root Sealer group was more than AH26 group, which was significantly comparative (p<0.001).Conclusion: Since the resin-based Sealer (AH26) was more trustworthy and effective in achieving apical seal in comparison to the Apatite root Sealer, its application is more recommended.

Objective: An ideal root filling materials must have the ability to seal the root canal system in three dimensions, be nontoxic and well tolerated by periradicular tissues, have dimensional stability, nonabsorbability, and not affected by the presence of moisture. MTA has good biological properties, and it is a mineralization-inducing material with different applications in endodontics. But owing to its physical properties, this material is not recommended as a root canal Sealer. However, a resin Sealer based on mineral trioxide aggregate (MTA Fillapex) was recently produced with this indication. Because Sealers are in contact with the periodontal tissues, it is important to know their cytotoxic effects. So the purpose of this study was to evaluate the cytotoxicity of MTA canal Sealer (MTA Fillapex) compared with Angelus MTA cement and AH26 Materials and Methods: Human periodontal ligament fibroblast cells (HPLF) were cultured in media previously exposed to MTA Fillapex, Angelus MTA cement and AH26 for 24 hours to 1week. Cytotoxicity was evaluated by methol-thiazol-diphenyl tetrazolium (MTT) assay in spectrophotometer to check cell survival and viability rate.Results: Cell viability remained above 50% in Angelus MTA group after 24 hours and declined after 48 hours and1week. AH26 induced an intermediate cytotoxicity in 24 hours but the cytotoxicity remained unchanged after 48 hours and 1week. MTA Fillapex was less toxic than AH26 after 24 hours but the toxicity of both materials was the same at 48 hours and 1week.Conclusion: This study showed that angelus MTA is less toxic in comparison with MTA Fillapex sealler and AH26.