BackgroundRecently a new generation of endodontic sealers has been developed based on calcium silicate as MTA Fillapex, Endoseal MTA, Total Fill BC Sealer, EndoSequence BC Sealer, iRoot SP, Endo CPM sealer, MTA-Angelus and ProRoot Endo Sealer. A review of literature was conducted to discuss the composition, physicochemical properties, and clinical perspectives of calcium silicate based sealers.Material and MethodsA literature search was conducted in PubMed and web of knowledge databases with appropriate MeSh terms and keywords. A total of 71 studies were reviewed for data extraction. Results and ConclusionsCalcium silicate based sealers showed suitable physical properties to be used as an endodontic sealer. However, its high solubility remains an important issue. They show good performance regarding calcium ion release, film thickness, and fowability. More researches are required about features of calcium silicate based sealers before recommending them for clinical applications. Key words:Calcium silicate, root canal filling materials, composition, physical properties.

IntroductionIt is very important to obtain a tight seal in obturated root canal, making it necessary to conduct clinical or laboratory studies on the sealability of endodontic materials. Different methodologies have been historically used to assess microleakage of different endodontic materials. The aim of the present study was to comprehensively review different material testing methods used in microleakage studies, their interpretation and importance in endodontic literature.Material and MethodsA systematic search was conducted in Medline, Cochrane, and Web of Science databases. In addition, the reference lists of review articles on the topic were searched. No language restriction was applied. Two independent reviewers screened the article.ResultsMicroleakage is considered the single most important risk factor responsible for apical periodontitis. Dye penetration, dye diffusion, bacterial and endototoxin infiltration, fluid filtration, glucose, caffeine and protein infiltration, radioisotope penetration, animal studies, and electrochemical or 3D evaluation are different methodologies used to assess dental leakage. 91 out of 177 articles in the primary search were included in the study. These methods are very divergent in their viewpoints; that is why their results cannot be easily compared. It is necessary to standardize microleakage detection methods in order to more correctly evaluate the phenomena that are found between the root canal wall and the root canal filling materials.ConclusionsAll the methods are useful if studies are performed strictly with large sample sizes and proper control groups and if the technique can be standardized. Furthermore, more evaluations of the reliability of the methods are strongly recommended. Key words:Dental leakage, review, root canal, material testing methods, data interpretation.

No abstract

No abstract

BackgroundThe purpose of this study was to compare the sealing ability of MTA Fillapex, Apatite Root Canal Sealer and AH26 sealers.Material and MethodsThe present in vitro study was carried out on 142 extracted single-rooted human mature teeth. The teeth were randomly divided into three experimental groups (n=44) and two control groups (n=5). Three root canal sealers were MTA Fillapex, Apatite Root Canal Sealer and AH26. The teeth in the control groups were either filled with no sealer or made completely impermeable. The root canals were prepared and obturated with gutta-percha and one of the sealers. The teeth were sterilized with ethylene oxide gas prior to the bacterial leakage assessment using Enterococcus faecalis. Leakage was evaluated every 24 hours for 90 days. Data were analyzed with descriptive statistical methods and chi-squared test. If the data were significant, a proper post hoc test was used. Statistical significance was set at P<0.05.ResultsThe positive control specimens exhibited total bacterial penetration whilst the negative control specimens showed no evidence of bacterial penetration. At the end of the study, the analysis of microleakage with chi-squared test showed no significant differences between the experimental groups (P<0.05). The results of chi-squared test analyzing the pair-wise differences between the groups considering the numerical values for leakage day indicated the lowest leakage with AH26 and the highest with Apatite root sealer.ConclusionsAccording to the results of the present study, sealing ability of AH26 was significantly higher than that of MTA Fillapex and Apatite Root Canal Sealer. Key words:Mineral Trioxide aggregate, root canal obturation, dental seal.

The chemical system of water + acetic acid + kerosene is frequently used in different liquid–liquid extraction studies. Accordingly, a comprehensive knowledge about this system is essential. The present study reports the capabilities of kerosene in extracting acetic acid from aqueous solutions at conventional temperatures of 293.2, 298.2, and 308.2 K and under an ambient pressure of 81.5 kPa. The cloud point method and refractive index measurement were employed in experiments. The distribution coefficient of the solute was within (0.0536–0.1161) and the important separation factor was within (5.07–82.84). The upper limit values in the ranges of the latter parameter were 1.36–8.80 times of those with other solvents. The distribution coefficient increased with temperature, but the separation factor diminished. The provided data were reproduced with the nonrandom two-liquid and universal quasichemical activity coefficient models, and the corresponding binary interactions were determined at each temperature. In this regard, a surrogate of kerosene, consisting of 80 wt % n-decane and 20 wt % 1,2,4-trimethylbenzene, was considered. The root mean square deviations of, respectively, (0.0035–0.0057) and (0.0056–0.0067) and also other criteria revealed good agreements between experimental and predicted values.

BackgroundBacteria like E. faecalis can produce intra- and extra-radicular biofilms. Theoretically, the adjustable penetration ability of lasers enables better access to root canal system. Therefore the aim of the present study was to compare the ability of photoactivated laser and 2.5% NaOCl irrigation solution to eliminate E. faecalis from the root canals by real-time PCR technique.Material and MethodsSixty extracted human upper central incisors were selected and sterilized in an autoclave. The root canals were infected with E. faecalis (PTCC 1237, Persian Type Culture Collection, Iran) and then incubated for 24 hours. The samples were randomly divided into 3 groups. No intervention was made in the control group (group 1). In group 2, laser therapy was performed with a power of 100 mW by diode laser for 120 seconds. In group 3, the canals were irrigated with 5 mL of 2.5% NaOCl; then all the samples were sonicated in 15 mL of normal saline in test tubes in order to isolate the bacteria. DNA extraction was performed followed by real-time PCR technique for all the samples.ResultsInhibition of bacterial growth in all the experimental samples was significantly more than that in the control group. There was a significant difference between photodynamic therapy and 2.5% NaOCl. The effect of NaOCl in all the samples was better than photodynamic therapy. The results of the mean CT (cyclic threshold) were 40, 30.2 and 15.35 for 2.5% NaOCl, photodynamic therapy and control group, respectively.ConclusionsBased on the results of this experimental study, 2.5% NaOCl eliminated E. faecalis from infected root canals more effectively compared to photodynamic therapy. Key words:Photoactivated laser, Enterococcus faecalis, antibacterial agents, sodium hypochlorite.

No abstract