Colorectal cancer (CRC) is one of the most frequent human malignant neoplasms. CRC has an estimated incidence of more than 1,000,000 new cases annually worldwide. Approximately one out of three people who develop CRC dies from the disease. Furthermore, CRC often affects inhabitants of industrialized countries in comparison to less developed countries. Several markers of colon cancer, including CEA, CA-19-9, TPS, TAG-72 and lysosomal hydrolases, have been identified and are now being adopted in routine clinical practice. Increased values of these markers are often the first signal of recurrence or metastases, which is useful in prediction and prognosis of clinical outcome of patients with CRC. Determination of the activity of lysosomal exoglycosidases in body fluids may bring some hope of improving diagnosis of colorectal cancer. However, it has to be remembered that currently the most effective diagnostic method of CRC is endoscopy.

The aim of the study was to compare ex vivo the toxic effects of six root canal sealers immediately after mixing or setting on human periodontal ligament fibroblasts (HPdLF). Freshly mixed (I group) or set (allowed to dry for 24 h) (II group) specimens of AH Plus Jet (AH), Apexit Plus (AP), MTA Fillapex (FL), GuttaFlow (GF), MetaSEAL Soft (META), and Tubli-Seal (TS) were prepared. HPdLF were exposed for 24 h to the specimens. 3-(4,5-dimethylthiazolo-2-yl)-2,5-diphenyltetrazolium bromide assay was used to examine the effect of the root canal sealers on mitochondrial metabolic activity. Fluorescein isothiocyanate (FITC)-annexin V (AnV) and propidium iodide staining followed by flow cytometry was used to identify the effects of the materials on cell apoptosis/necrosis. Statistical analyses were performed by one-way ANOVA followed by post hoc tests, and significance was determined at P < 0.05. Most materials from the two groups reduced the viability of the cultured cells compared with the control group (P < 0.05). Statistical analysis showed significant differences in HPdLF viability between the individual materials in each group (P < 0.001). AH and AP induced a significant increase in the percentage of apoptotic cells, while TS, FL, and META elevated the proportion of necrotic cells compared with other materials and the controls (p < 0.05). The cytotoxic effects of the tested root canal sealers (both fresh and set) on HPdLF varied. Both forms of sealers were able to cause toxic effects by inducing apoptosis and necrosis in HPdLF. The cytotoxicity of FL, META, TS was mainly associated with necrosis, while AH and AP with apoptosis.

Among the materials studied, only EP, AP and AH Plus were able to elevate the pH level that would allow inactivation of microorganisms in the root canals and promote healing of inflamed periapical tissues. However, the low alkalizing potential of G and R can be modified by the concomitant application of sealers producing alkaline pH.

Background. Actinomyces species have a low virulence and pathogenicity, but under specific circumstances they may be involved in root canal and periapical tissue infections. Objectives. The aim of the study was to investigate the antibacterial activity of various root canal sealers on standardized strains of Actinomyces. Material and methods. The materials tested in this study included AH Plus™ Jet (AH), Apexit® Plus (AP), Endomethasone N (EN), GuttaFlow® (GF), Hybrid Root SEAL (HB), MTA Fillapex (FL), Real® Seal (RCS), Roeko Seal Automix (RSA), Sealapex™ (SP), and Tubli-Seal™ (TS). The antibacterial effect of the freshly mixed sealers on standardized strains of Actinomyces israelii NCTC 8047 and Actinomyces viscosus ATCC 15987 was evaluated with the use of the agar diffusion test (ADT). The results were obtained with measuring the diameter of the growth inhibition zone at 96 h and 1, 2, 3, and 4 weeks, and were analyzed in time using repeated measures analysis of variance (ANOVA). Statistically significant differences among the materials were determined using one-way ANOVA and Tukey's post hoc testing. A paired Student's t-test was applied to compare the susceptibility of particular strains to each sealer. The critical level of significance for all tests was p < 0.05. Results. Most sealers demonstrated growth inhibition zones against both tested bacteria, except for RSA and GF. Actinomyces viscosus was significantly more susceptible than A. israelii to AP, RCS (p < 0.001) and TS (p = 0.012). Actinomyces israelii was significantly more susceptible than A. viscosus to EN, HB and SP (p < 0.001). Conclusions. The antimicrobial effect of the examined materials varied considerably depending on the type of material and bacterial species tested. Most of the tested root canal sealers exhibited antibacterial activity on standardized strains of Actinomyces, with FL showing the highest antibacterial effect on both bacterial strains. Importantly, both standardized strains of Actinomyces were characterized by varied sensitivity to root canal sealers.

Aim of the study. To determine and compare the antibacterial activity of various root canal sealers against selected strains of anaerobic bacteria: Fusobacterium nucleatum ATCC 25586, Porphyromonas gingivalis ATCC 33277, Peptostreptococcus anaerobius ATCC 27337. Material and Methods. The materials tested in this study included AH Plus Jet (AH), Apexit Plus (AP), Endomethasone N (EN), Epiphany (EP), GuttaFlow (GF), Roeko Seal Automix (RSA), Sealapex (SP) and Tubliseal (TS). The antibacterial effect of the freshly mixed sealers on the above mentioned strains of bacteria was evaluated with the use of the agar diffusion test. After inoculation with the bacteria and applying the materials, the agar plates were incubated at 37°C for one week in an atmosphere of 5-10% CO 2. The results were obtained