RESUMO
Context: Different factors can affect the marginal adaptation of MTA. Aims: The present study was designed to investigate the effect of two ultrasonic irrigation methods on the marginal adaptation of MTA plug in open apex teeth by scanning electron microscope. Settings and Design: Thirty single mature teeth were included in this in vitro experimental prospective study. Materials and Methods: A total of 5 mm thickness of MTA plug was inserted at the end of the canals and after 24 h an ultrasonic file was used to irrigate the canals and remove the MTA remnants. Teeth were randomly divided into three groups: In the first and second groups, the canals were irrigated for 1 min by 2.5% sodium hypochlorite as #25 ultrasonic file was in direct contact and 1 mm away from MTA plug, respectively. The third group was not irrigated and left as control. A total of 1 mm transverse sections were prepared through the coronal and the apical parts of MTA plug and specimens were prepared for SEM analysis. The extent of gap was measured linearly under SEM device. Statistical Analysis Used: Statistical analysis of the results was performed using the kruskal-Wallis test by SPSS software ver.18(a = 0.05). Results: There was no significant difference between groups regarding the marginal gap size in apical (P: 0.17) and coronal sections (P: 0.33). However, the mean marginal gap size was higher in apical section compared to coronal section. Conclusions: It can be concluded that ultrasonic irrigation dose not adversely affect the marginal adaptation of MTA plugs.
RESUMO
Background: An apical seal is an important factor in achieving success in surgical endodontics. Aim: The purpose of this study was to compare the sealing properties of mineral trioxide aggregate (MTA) with a new ceramic based root end filling material (Cold Ceramic) in different environments. Materials and Methods: One hundred teeth were selected. The root canals were instrumented and obturated. Except for the apical 2 mm, the root surfaces were sealed. After root resection, 3 mm depth root-end cavities were prepared. For each material, roots were divided into 3 equal subgroups and the root-end filling was done in different environments (dry, saliva contaminated, blood contaminated). Five roots served as positive and 5 roots as negative controls. Samples were immersed in 2% methylene blue dye. Roots were sectioned longitudinally and examined under stereomicroscope to record the extension of dye penetration. Results: All experimental groups demonstrated dye penetration. The lowest linear leakage was seen in Cold Ceramic blood contaminated group while the highest leakage was observed in MTA blood contaminated group. The linear dye penetration of both MTA and Cold Ceramic (CC) groups did not show any significant differences among different environments. Also, the difference between MTA and CC was not significant in dry and saliva contaminated subgroups. Only the difference between dye penetration of MTA and CC in blood contaminated subgroups showed significant difference ( P = 0.008). Conclusion: The sealing property of this ceramic based root end filling material (Cold Ceramic) is better than MTA in blood contaminated condition and at least similar to MTA in other conditions.
RESUMO
Aims: Comparing the calcium concentration and pH levels of Ca(OH) 2 medicament placing in pulp chamber and root canal. Materials and Methods: Ninety-nine extracted human mandibular second premolars were instrumented to size #40 k file. Nine teeth served as the control group and the remaining teeth were assigned into two groups. Group 1-Ca(OH) 2 was placed in the dried pulp chamber, while root canals remained wet with normal saline; group 2-Ca(OH) 2 was placed in dried root canals. In control group, canals remained wet without medication. Each group was divided into 3 sub-groups of 15 teeth in which pH and calcium concentration were measured in three intervals of 2 days, 1 week, and 2 weeks by pH meter and atomic absorption spectrometer system, respectively. Findings were assessed using Kruskal-Wallis and t-test. Results: At 1 and 2 weeks, the calcium concentration had increased without being significantly different from Ca(OH) 2 placed either in the root canal or in the pulp chamber. Ca(OH) 2 placed in the pulp chamber or root canal provided similar pH values (P=0.362). Conclusions: Placing Ca(OH) 2 in pulp chamber is as effective as placing it in the root canal.