The Effect of Intracanal Irrigants on Push out Bond Strength of CEM, Root MTA and Angelus MTA Cements to the Dentin Wall

Background and Objective: To reduce microbial contamination in cases such as perforation treatment, it is necessary to use irrigants after cement placement. The aim of the present study is to investigate the effect of intracanal irrigants on the push out bond strength of CEM, Root MTA and Angelus MTA cements to the dentin wall. Methods: In this laboratory research, 150 cross-section samples from the mid-root region of single canal teeth without caries with a thickness of 1 mm, which were randomly divided into 3 groups of 50 and filled with CEM cement, Root MTA or Angelus MTA, were examined. After the cements were set, the samples of each group were divided into 5 subgroups of 10; 4 subgroups were cleaned with sodium hypochlorite, EDTA, normal saline, 2% chlorhexidine for 30 minutes, and one subgroup was not cleaned as a control group. Then, the push out bond strength of cement with the dentin wall (MPa) and the failure pattern of the samples were evaluated. Findings: Different cleaning methods did not show any significant effect on the bond strength of CEM, Root MTA and Angelus MTA cements. In the cleaning method with saline, the bond strength of Angelus MTA (6.3±1.98) was higher than Root MTA (2.1±3.61) (p=0.004). In the cleaning method with 2% chlorhexidine, the bond strength of Angelus MTA cement (8.72±3.13) was higher compared to CEM (3.87±1.35) and Root MTA (4.66±1.76) (respectively p<0.001 and p=0.001). The most common type of failure in the Angelus MTA group was of the adhesive type, and in the CEM cement and Root MTA groups, it was of the mixed type. Conclusion: The results of the study showed that different cleaning methods have no effect on the push-out bond strength of the examined cements

The Effect of Intracanal Irrigants on Push out Bond Strength of CEM, Root MTA and Angelus MTA Cements to the Dentin Wall

Background and Objective: To reduce microbial contamination in cases such as perforation treatment, it is necessary to use irrigants after cement placement. The aim of the present study is to investigate the effect of intracanal irrigants on the push out bond strength of CEM, Root MTA and Angelus MTA cements to the dentin wall. Methods: In this laboratory research, 150 cross-section samples from the mid-root region of single canal teeth without caries with a thickness of 1 mm, which were randomly divided into 3 groups of 50 and filled with CEM cement, Root MTA or Angelus MTA, were examined. After the cements were set, the samples of each group were divided into 5 subgroups of 10; 4 subgroups were cleaned with sodium hypochlorite, EDTA, normal saline, 2% chlorhexidine for 30 minutes, and one subgroup was not cleaned as a control group. Then, the push out bond strength of cement with the dentin wall (MPa) and the failure pattern of the samples were evaluated. Findings: Different cleaning methods did not show any significant effect on the bond strength of CEM, Root MTA and Angelus MTA cements. In the cleaning method with saline, the bond strength of Angelus MTA (6.3±1.98) was higher than Root MTA (2.1±3.61) (p=0.004). In the cleaning method with 2% chlorhexidine, the bond strength of Angelus MTA cement (8.72±3.13) was higher compared to CEM (3.87±1.35) and Root MTA (4.66±1.76) (respectively p<0.001 and p=0.001). The most common type of failure in the Angelus MTA group was of the adhesive type, and in the CEM cement and Root MTA groups, it was of the mixed type. Conclusion: The results of the study showed that different cleaning methods have no effect on the push-out bond strength of the examined cements

Indoor and outdoor airborne bacterial air quality in day-care centers (DCCs) in greater Ahvaz, Iran

Air pollution is considered as one of the major causes of environmental health problems. Young children and infants are more susceptible than adults due to age and higher sensitivity to environmental hazards. The aim of the present study was to an investigation of indoor/outdoor, regional and seasonal variations of airborne bacteria and PM concentrations of six randomly selected child day-care centers (DCCs) in greater Ahvaz. bio-aerosol sampling, PM measurement, and meteorological parameters data capture were performed monthly in DCCs of industrial, high traffic and residential regions during autumn, winter, and spring. The results revealed that the highest and the lowest of indoor and outdoor of mean concentrations of airborne bacteria were observed in the DCCs in the high traffic regions and residential area, respectively. The monthly highest and the lowest mean of culturable bacteria was determined in February (812 CFU/m3) and November (188 CFU/m3), respectively. There is a positive correlation between concentrations of PM and airborne bacteria in the DCCs during the study. The highest mean concentrations of airborne bacteria in indoor air samples were measured in winter season in high traffic and residential regions with 789 CFU/m3 and 646 CFU/m3, respectively, this value for outdoor samples was determined in spring and winter seasons at industrial and residential regions with 335.41 CFU/m3 and 306.34 CFU/m3, respectively. The highest and the lowest indoor/outdoor (I/O) ratio of mean concentrations of bacteria were determined in the autumn and spring at the industrial region with I/O ratio of 23.17 and 1.37, respectively. In the indoor and outdoor conditions of all DCCs, the Gram-positive bacteria were the dominant species which shows higher concentration than Gram-negative bacteria. The dominant bacterial genera were Bacillus spp. and Staphylococcus spp. in air samples. The results of the present study suggest strongly that instead of natural ventilation using windows, use of artificial ventilation and air conditioning systems could improve indoor air quality (IAQ) in the DCCs. Facial air filters and air treatment devices are recommended particularly at the time of dust event days in cities like Ahvaz. © 2019 Elsevier Lt