Assessment of antibacterial activity of endodontic sealers by a direct contact test

Abstract

It is recognized that endodontic success depends on bacterial elimination from the root and root canal system. Antibacterial activity of endodontic sealers can improve the success rate of endodontic treatment, provided the physical properties are not compromised. The aim of this study was to evaluate the antimicrobial properties of two endodontic sealers (AH26 and Endoflas) using a direct contact test (DCT) which was designed for this purpose. The DCT is based on measuring the effect of close contact between test bacteria and the tested material on the kinetics of bacterial outgrowth using a temperature controlled microplate spectrophotometer (THERMOmax). For comparison, the agar diffusion test (ADT) was performed for both materials. The results of the DCT showed that Endoflas was a significantly more potent bacterial growth inhibitor than AH26, whereas when assessed with the ADT, AH26 was capable of producing a larger inhibition zone than Endoflas. The DCT, by being quantitative and virtually independent of solubility and diffusion, was found more suitable to assay solid surfaces. The results demonstrated the added value of DCT in the study of the antimicrobial properties of endodontic sealers.

A comparative study of apical microleakage of different root canal sealers by apical dye penetration

“…Considering the main purpose of using sealers is to fill gaps within the irregular root canal system, their solubility and disintegration should be as low as possible. 21 Disintegration of the sealer or undetected voids in the filling mass may create leakage channels that allow periradicular tissue fluids to reach residual bacteria within tubules and provide nutrient for their growth. 22 There are chances of seepage of fluids into the apical foramen following drying, or due to the inability of the paper points to reach the full apical extent of extremely small or tortuous canals.…”

Synergetic inactivation of <i>Staphylococcus epidermidis</i> and <i>Streptococcus mutans</i>in a TiO2/H2O2/UV system

“…The bacterial viability test employed in this study originates from a DCT developed by Weiss et al 48 for evaluating antibacterial properties of non-soluble materials. In short, a small amount of bacterial suspension, typically 5-10 μL, is spread over the surface of a substrate.…”

Physicochemical and biological properties of a novel injectable polyurethane system for root canal filling

“…The direct contact test (DCT), which was developed by Weiss et al 24 is an effective method for evaluating the antibacterial activity of root canal sealing materials; this method is based on the turbidimetric determination of bacterial growth in 96-well microtiter plates. The antibacterial activities of the sealers were tested after two different treatments were administered for experimental reliability: samples were used after just curing (designated as fresh samples), and fresh samples were set in a humid atmosphere at 37°C for 7 days and washed with PBS before testing; these were designated as 7-d samples.…”