Antibacterial efficacy of copper-added chitosan nanoparticles: a confocal laser scanning microscopy analysis.

The aim of this study was to evaluate the antibacterial efficacy of copper added chitosan nanoparticles (CU-CNPs) as an irrigation solution with different irrigants in terms of eliminating Enterococcus Faecalis (E. faecalis) from the root canals. Fifty mandibular premolar teeth were prepared and infected with E. faecalis for 21 days. After the incubation period, samples were randomly divided into a control group irrigated with distilled water and 4 experimental groups (n = 10) irrigated with as follows, %6 NaOCl, %6 NaOCl + %9 editronate (HEBP), Chitosan nanoparticles (CNPs), and CU-CNPs. To calculate the proportion of dead E. faecalis cell volume, stained using LIVE/DEAD BacLight Bacterial Viability Kit and were scanned using confocal laser scanning microscope (CLSM). All the irrigation solutions significantly (P < .05) killed the bacteria in the canal, except for the control group. CU-CNPs solution killed the highest (P < .05) number of bacteria compared with the other experimental groups. No significant difference was found between CNPs, NaOCl + HEBP, and NaOCl in terms of antibacterial activity. CU-CNPs solution was exhibited higher antibacterial efficacy against E. faecalis.

Comparison of cyclic fatigue resistance and bending properties of two reciprocating nickel-titanium glide path files.

AIM: To compare the cyclic fatigue resistance and bending properties of R-Pilot and WaveOne Gold (WOG) Glider files, at intracanal temperature (35°C). METHODOLOGY: Forty R-Pilot and 40 WOG Glider files were subjected to a cyclic fatigue resistance test (n = 20), calculating the time to fracture (TTF) in an artificial stainless steel canal. The length of the fractured file tips (FL) was also measured. The fracture surface of fragments was examined with a scanning electron microscope, and the cross-sectional area of the fractured surfaces was measured. Flexibility of the tested files (n = 20) was determined using 45° bending test. Data were analysed statistically using the Mann-Whitney U-test at 5% significance level. RESULTS: Time to fracture was significantly higher in the R-Pilot group compared to the WOG Glider (P < 0.05). There was no significant difference between groups for fracture length. The bending resistance of R-Pilot files was significantly greater than WOG Glider files (P < 0.05). CONCLUSIONS: A significant greater cyclic fatigue resistance was observed for R-Pilot files compared to WOG Glider instruments, although the bending resistance of WOG Glider files was lower.

Effect of multiple autoclave cycles on the surface roughness of HyFlex CM and HyFlex EDM files: an atomic force microscopy study.

AIM: To compare the effect of autoclave cycles on the surface topography and roughness of HyFlex CM and HyFlex EDM instruments using atomic force microscopy (AFM) analysis. METHODOLOGY: Eight new files of each brand were subdivided into four subgroups (n = 2/each subgroup). One group was allocated as the control group and not subjected to autoclave sterilization. The other three groups were subjected to different numbers (1, 5, and 10) of autoclave sterilization cycles. After the cycle instruments were subjected to AFM analysis. Roughness average (Ra) and the root mean square (RMS) values were chosen to investigate the surface features of endodontic files. The data was analyzed using one-way ANOVA and post hoc Tamhane tests at 5% significant level. RESULTS: The lowest Ra and RMS values were observed in the HyFlex EDM files that served as the control and in those subjected to a single cycle of autoclave sterilization (P < 0.05). The highest Ra and RMS values were observed in the HyFlex CM and HyFlex EDM files that were subjected to 10 cycles of autoclave sterilization (P < 0.05). The surface roughness values of the HyFlex CM group showed a significant increase after ten autoclave cycles, whereas those of the HyFlex EDM group exhibited a significant change after five autoclave cycles (P < 0.05). CONCLUSIONS: Although the initial surface roughness values of the HyFlex EDM files were lower than those of the HyFlex CM files, the surface roughness values of the EDM files showed a statistically significant increase after 5 cycles of autoclave sterilization. In contrast, the surface roughness values of the HyFlex CM files did not increase until 10 cycles of autoclave sterilization. CLINICAL RELEVANCE: Present study indicated that autoclave sterilization negatively affected the surface roughness of the tested NiTi files.

Cyclic fatigue resistances of several nickel-titanium glide path rotary and reciprocating instruments at body temperature.

AIM: To compare the cyclic fatigue resistance of the One G, ProGlider, HyFlex EDM and R-Pilot glide path NiTi files at body temperature. METHODOLOGY: Twenty One G (size 14, .03 taper), 20 ProGlider (size 16, .02 taper), 20 HyFlex EDM (size 10, .05 taper) and 20 R-Pilot (size 12.5, .04 taper) instruments were operated in rotation at 300 rpm (One G, ProGlider and HyFlex) or in reciprocation (R-Pilot) at 35 °C in artificial canals that were manufactured by reproducing the size and taper of the instrument until fracture occurred. The time to fracture was recorded in seconds using a digital chronometer, and the length of the fractured fragments was registered. Mean data were analysed statistically using the Kruskal-Wallis test and post hoc Tukey tests via SPSS 21.0 software. The statistical significance level was set at 5%. RESULTS: The cyclic fatigue resistance of the R-Pilot files was significantly greater than the other instruments, and the One G was significantly lower (P < 0.05). There was no difference between the HyFlex EDM and the ProGlider (P > 0.05). No significant difference (P > 0.05) was evident in the mean length of the fractured fragments of the various instruments. CONCLUSIONS: The cyclic fatigue resistance of the R-Pilot reciprocating glide path file was significantly greater than that of the rotary HyFlex EDM, ProGlider and One G glide path files.

Cyclic fatigue resistance of R-Pilot, HyFlex EDM and PathFile nickel-titanium glide path files in artificial canals with double (S-shaped) curvature.

AIM: To examine the cyclic fatigue resistances of R-Pilot, HyFlex EDM and PathFile NiTi glide path files in S-shaped artificial canals. METHODOLOGY: Twenty R-Pilot (12.5/.04), 20 HyFlex EDM (10/.05) and 20 PathFile (19/.02) single-file glide path files were included. Sixty files (n: 20/each) were subjected to static cyclic fatigue testing using double-curved canals until fracture occurred (TF). The number of cycles to fracture (NCF) was calculated by multiplying the rpm value by the TF. The length of the fractured fragment (FL) was determined by a digital microcaliper. Six samples of fractured files (n: 2/each) were examined by SEM to determine the fracture mode. The NCF and the FL data were analysed using one-way anova, post hoc Tamhane and Kruskal-Wallis tests using SPPS 21 software. The significance level was set at 5%. RESULTS: In the double-curved canal, all the files fractured first in the apical curvature and then in the coronal curvature. The NCF values revealed that the R-Pilot had the greatest cyclic fatigue resistance, followed by the HyFlex EDM and PathFile in both the apical and coronal curvatures (P < 0.05). CONCLUSIONS: R-Pilot NiTi glide path files, used in a reciprocating motion, had the greatest cyclic fatigue resistance amongst the tested NiTi glide path files in an artificial S-shaped canal.

Acne: prevalence, perceptions and effects on psychological health among adolescents in Aydin, Turkey.

BACKGROUND: Acne vulgaris is a common disease among adolescents and known to have adverse effects on psychological status. METHODS: A cross-sectional study was conducted on 600 participants by means of a questionnaire designed for this study in high school students. In addition, an objective evaluation of acne in participants was undertaken. The questionnaire consisted of questions about acne, General Health Questionnaire (GHQ) and Rosenberg Self-Esteem Scale (RSES). RESULTS: Five hundred and sixty-three questionnaires out of 600 were answered and 550 adolescents who gave permission for examination were evaluated. The study population consisted of 303 girls and 260 boys between the ages 13 and 19, and the mean age was 15.24 +/- 1.05 years. Acne prevalence was 63.6% with 29.2% non-inflammatory and 34.4% inflammatory acne. It was more prevalent and severe in boys than in girls. Not the objective but the subjective severity of acne and opinion that one could benefit from acne treatment was found to be related to anxiety, depression and self-esteem. Factors implicated among causes of acne were food, bad skin hygiene and hormones in decreasing frequency. Forty-eight per cent of adolescents expect a maximum duration of 4 weeks for treatment. CONCLUSION: Despite the high prevalence of acne, there is still much deficiency of knowledge and wrong beliefs about acne. This indicates that there is an urgent need for education about etiopathogenesis, potential complications and importance of effective treatment for acne. Effective treatment may make significant contributions for the mental health of adolescent and as well as adult populations.

Predictors of distant metastasis at presentation in breast cancer: a study also evaluating associations among common biological indicators.

BACKGROUND: To investigate the correlation among some of the commonly used clinical, pathological factors and newer biological indicators, and to identify the independent predictors of distant metastasis at presentation in patients with breast cancer. METHODS: The pathological specimens from 73 patients with breast cancer were retrospectively evaluated by immunohistochemistry. Data on 13 biological indicators; ER, PR, P53, c-erbB-2, PCNA, CEA, Ki-67, Vimentin, Ulex, Nm23, Cathepsin D, Factor VIII, PS2 together with clinical and pathological factors were collected. RESULTS: A number of highly significant correlations were found among the biological indicators studied. By logistic regression analysis, the predictors of distant metastasis at presentation in univariate tests were tumor diameter, number of lymph nodes involved, P53, c-erbB-2 and grade. In multivariate analysis, tumor diameter (P = 0.042, HR: 1.88(1.02-3.44)), c-erbB-2 expression (P=0.035, HR: 18.20 (1.23-268.66)) and grade (P=0.010, HR: 8.05(1.66-39.00)) retained their significance. CONCLUSION: Our findings show that inactivation of suppressor genes, expression of oncogenes, loss of differentiation, augmentation of proliferative activity, metastatic potential, angiogenesis and hormone receptor status are all interrelated facets of breast cancer pathogenesis. Patients with tumors overexpressing c-erbB-2 or with bigger or higher-grade tumors probably need to be more carefully evaluated for the presence of distant metastasis, thus be better staged, at presentation. This may be a new reason to test c-erbB-2 routinely in all patients with breast cancer in addition to its well-known prognostic and predictive uses.

Interplay between lipids and viral glycoproteins during hemolysis and fusion by influenza virus.

Since mixtures of lipids alone are known to elicit membrane fusion without participation of fusion proteins, the role of viral lipids in the so-called virus-induced hemolysis and cell fusion has been investigated, using as a model the fowl plague virus (influenza A/FPV/Rostock/H7N1). The experiments were planned in a way that allowed quantitative modification of viral lipids without changing envelope glycoproteins. Under the conditions employed, cholesterol oxidase of Nocardia erythropolis and phospholipase C of Bacillus cereus were shown to completely modify their substrates in the virus without altering virus-associated hemagglutinating and neuraminidase activities. It was found with such enzyme treatment that virus-induced hemolysis and cell fusion are greatly influenced by cholesterol and phospholipids of the envelope. It became clear, that hemolysis and fusion are differently dependent on the nature of lipid components even though mediated by the same viral glycoproteins.