الفهرس 
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Abstract
Summary
Endodontic sealers have the prime functions of sealing off voids between gutta-percha and root canal walls, embedding residual bacteria and filling root canal irregularities, including lateral canals and isthmus. The benchmarks of an ideal sealer are tissue tolerance, no setting shrinkage, suitable working and setting time, adhesiveness, radiopacity, insolubility to oral and tissue fluids, antibacterial properties and ability to create a seal. However, conventional root canal sealers fall short of fulfilling all of these criteria. This in vitro study aimed at testing some physicochemical and biological properties of TotalFill bioceramic-based sealer in comparison to Sealapex calcium hydroxide-based sealer regarding their flowability, pH and calcium ion release levels, antibacterial and cytotoxic effects.
The flowability of the sealers was evaluated according to the simple press method dictated in the ISO (6876:2001) specification for root canal sealing materials. Ten specimens of each sealer measuring 0.05ml were pressed under a glass plate and an additional mass for a total weight of 120 gm total then the mean diameters of the compressed sealer disks were measured. TotalFill BC sealer showed a significantly higher mean diameter compared to Sealapex sealer; however, both sealers complied with the ISO specification 6876 which requires a minimum 20mm as an acceptable flow value.
The pH and calcium ion release levels were evaluated. Twenty polyethylene tubes were filled with the tested sealers (10 each), immersed in glass flasks each containing 10 ml deionized water and stored in an incubator at 37º C with the water changed after 1, 7, 28 days and 3 months. Eluates were measured for pH with an advanced electrochemistry digital pH meter and for Ca+2 ion release with a flame atomic absorption spectrometer. TotalFill upheld a significantly higher pH and Ca+2 ion release levels than Sealapex at all evaluation times.
The antibacterial effect against Enterococcus faecalis bacteria was measured using the turbidimetry–based direct contact test testing fresh samples and 1, 3, and 7 days’ set samples. Both sealers demonstrated a significantly high antibacterial effect (low optical density) compared to the control group; however, TotalFill showed significantly lower optical density values (higher antibacterial effect) compared to Sealapex.
The cytotoxic effect was measured using MTT assay as described in the recommendation of ISO 10993-5:2009 utilizing four concentrations (Neat, 1:1, 1:2 and 1:4) of both fresh and set sealer samples for subsequent culturing after 1, 2 and 3 days. Both sealers demonstrated a time-dependent and dose-dependent cytotoxic effect which decreased with setting and dilution of the extracts. However, TotalFill sealer demonstrated better biocompatibility and less cytotoxicity (mild to moderate) in comparison to Sealapex sealer (moderate to severe).
This study demonstrated that in term of calcium hydroxide-related properties, TotalFill bioceramic sealer was far superior compared to Sealapex calcium hydroxide sealer.