Introduction: Providing adequate coronal seal of temporary filling materials is critical for the success of root canal therapy. The aim of this in vitro study was to compare coronal seal ability of three restorative materials over different periods of time.Materials and Methods: Ninety-eight molar teeth were selected. Once access cavities were prepared, teeth were divided randomly into three time groups (1 day, 1 week, and 4 weeks). Each group was then subdivided into three groups of 10 teeth. Each subgroup was restored using one of three restorative materials including Coltosol, Cavizol and Zonalin and then incubated in distilled water at 37oC. The samples were then immersed in 2% methylene blue dye. After rinsing and drying, teeth were sectioned longitudinally and examined for dye penetration. Kruskal-Wallis and Mann Whitney U tests were used to analyze the data.Results: All experimented materials showed increasing leakage from the 1st day to the 4th week. Zonalin showed more leakage than Coltosol and Cavizol at each time interval (P<0.05), but there was no significant difference between Coltosol and Cavizol.Conclusion: Coltosol and Cavizol are suitable temporary materials for up to 1 week.

Introduction: This in vitro study aims to evaluate the coronal and apical sealing ability of gutta-percha (GP) root filling used with either mineral trioxide aggregate (MTA), new endodontic cement (NEC) or AH26 as filler/sealers.Materials and Methods: Forty eight single-rooted extracted teeth were selected, decoronated and then instrumented. Samples were randomly divided into three experimental (n=12) and two control groups (n=6). In group 1, root canals were filled using lateral condensation technique (L); while single cone technique (S) was used for groups 2 and 3. AH26, MTA and NEC were the root canal sealer/fillers in groups 1, 2 and 3, respectively. Samples were immersed in 1% methylene-blue dye and then independently centrifuged apically and coronally. The roots were split longitudinally and linear extent of dye penetration was measured with a stereomicroscope from apical and coronal directions. Data were analyzed using One-way ANOVA and T-test.Results: No statistical differences in mean apical dye penetration between groups LGP/AH26, SGP/MTA and SGP/NEC were found; SGP/NEC group showed significantly less coronal dye penetration (P<0.001).Conclusion: Considering the limitations of this in vitro study, it was concluded that the simple single cone technique with NEC can provide favorable coronal and apical seal.

Background and Aim: Complete obturation of the prepared root canal is an essential step in endodontic treatment. Combination of gutta-percha and a sealer is widely used in clinical practice for root canal obturation, thus microleakage studies on sealing properties of these materials constitute an important part of endodontic researches. The aim of this study was to evaluate the microleakage of three root canal sealers: Apexit, AH26 and Dorifill by electrochemical method.Materials and Methods: In this experimental study, 55 extracted human maxillary and mandibular cuspids were used. The coronal part of teeth was removed and the root canals were prepared using the step-back technique. The specimens were randomly divided into 3 groups of 17 samples each. Teeth in each group were filled with one of the sealers and gutta-percha by lateral condensation technique. 4 specimens served as positive and negative controls. An electrochemical method was used for evaluation of apical leakage with the electrical source potential of 10 V. Measurements of current flow through the test system were recorded every 72 hours. Data were analyzed by Kruskall Wallis and Mann Whitney tests. P<0.05 was considered as the level of significance.Results: All specimens of the three groups showed low initial leakage that increased during the test period.The mean leakage in Apexit group was higher than AH26 and Dorifill groups. The lowest mean leakage was related to Dorifill group. Although no statistically significant difference was observed between this sealer and AH26.Conclusion: The results of this study revealed that the best apical seal was obtained using Dorifill and AH26 sealers. The poorest result was observed in Apexit.

Introduction: Coronal microleakage may significantly reduce the prognosis of endodontic treatment. Temporary restorative materials have a crucial role in preventing the infection of root canals between and after endodontic treatment. This in vitro study was designed to evaluate the coronal microleakage of three temporary restorative materials used in endodontics: Coltosol, Cavisol and Cina.Materials and Methods: Seventy-five human premolars and molars were selected for this in vitro study. Access cavities were prepared and amalgam placed on the orifices of canals; the occlusal surfaces were then reduced by 4mm for the temporary restoration. The teeth were divided into three experimental groups of 23 teeth and two control groups of 3 teeth. The access cavities in each group were sealed using one of the test materials and thermal cycling was applied (5-55°C for 150 cycles). Surfaces were then covered with nail polish and wax; the teeth were immersed in 2% methylene blue dye for 7 days. The teeth were rinsed, dried, and sectioned mesiodistally and evaluated under a stereomicroscope for microleakage. Data was analyzed using Kruskal-Wallis and Mann U Whitney tests.Results: The lowest microleakage value was observed in Cavisol and Coltosol groups and the highest in Cina group (P<0.001). There was no statistical difference between Cavisol and Coltosol.Conclusion: Coltosol and Cavisol have appropriate sealing properties as temporary restorations, but the sealing ability of Cina was questionable.

Introduction: The purpose of this in-vitro study was to investigate the influence of the remaining calcium hydroxide (CH) as an intracanal dressing on the apical sealing ability of three endodontic sealers.Materials and Methods: Sixty-six single and straight canals of recently extracted human permanent maxillary central incisors were used. All canals were prepared and sixty of them were randomly divided into two groups with (group 1) and without (group 2) CH medication.Each of these groups was divided into three experimental groups using AH26 (group a), Dorifill (group b), and Apexit (group c). Six remained teeth were divided into positive and negative groups of three each. Root canals were filled with gutta-percha and AH26 (groups 1a, 2a), Dorifill (groups 1b, 2b) and Apexit (groups 1c, 2c) using lateral condensation technique. The apical third of the roots were placed in Pelikan ink for one week. Linear dye penetration was recorded using a stereomicroscope and a digital caliper. Data were compared with analysis of variance (ANOYA).Results: Observed leakage in groups which were filled with Apexit sealer was significantly different (P<0.002). There was no significant difference among groups which were filled with Dorifill and AH26.Conclusion: Calcium hydroxide did not influence the apical sealing ability of AH26 and Dorifill, while it did improve the apical sealing ability of Apexit sealer.

Introduction: The aim of this study was to compare the scaling ability of Real Seal (RS) and Gutta-percha (GP).Materials and Methods: Forty nine extracted human maxillary central incisors were used. The coronal part of each tooth was removed; the root canal was prepared using the crown dOW11technique and apical enlargement to rotary file # 40. The specimens were randomly divided in to 3 groups of 15 each and two control groups of 2 each. Group 1, was obturated with RS and group 2 and 3 were obturated with GP and AH26 sealer by lateral condensation technique. In group I and 3 the smear layer was removed by 5mL of 5.25% NaOCl and 3mL of 17% EDTA. Leakage of the obturated roots was measured using the fluid filtration technique. This method was done at 2 min intervals for 8 min. data were analyzed using ANOVA and Tukey tests.Results: Statistical analysis indicated significant differences between groups 2 with I and 3. The most leakage value was observed in the group 2.Conclusion: Root canal filling with RS or GP in combination with smear layer removal showed better sealing. Therefore, the smear layer has more effect one apical leakage than the obturation system.