An evaluation of dental paste-like bulk-fill composite wear using intra-oral scanner.

This study evaluates the wear resistance of dental paste-like bulk-fill composites compared to conventional paste-like composite resins using an intraoral scanner and 3-D analyzing software. Six different dental composite materials, including five bulk-fill composites and one conventional composite, were tested alongside natural human enamel as a control group. A computer-controlled chewing simulator for wear testing. A one-way ANOVA test was used to identify any significant differences between the means of the tested dental composite materials α=0.05. The results showed variability among bulk-fill composites, with some demonstrating wear resistance similar to conventional composites (p<0.05). Human enamel displayed the lowest wear values, but some bulk-fill composites matched this resistance(p>0.05). Significant variability was observed among bulk-fill composites but the results were comparable to those of conventional composites. The enamel control group demonstrated the lowest wear values, with some bulk-fill composites showing similar wear resistance. This study provides valuable information about the wear resistance of contemporary bulk-fill composite materials, commonly used in current clinical practice, contributing to enhancing clinical procedures.

Marginal adaptation of bulk-fill resin composites with different viscosities in class II restorations: a micro-CT evaluation.

BACKGROUND: The purpose of this study is to evaluate the marginal adaptation of bulk-fill resin composites with different viscosities (paste-like and flowable) in Class II restorations using micro-CT imaging. METHODS: Forty extracted human molars were used. Mesial and distal Class II box cavities (approximately 3 mm x 3 mm x 4 mm) were prepared for each tooth, with cavity floors located 1 mm below the enamel-cementum junction. Following adhesive application, teeth were restored using eight different groups: Group XB: X-tra Base Bulk-fill Flowable (VOCO), Group XF: X-tra Fill Bulk-fill (VOCO), Group FB: Filtek Bulk-fill Posterior (3 M ESPE), Group FF: Filtek Bulk-fill Flowable (3 M ESPE), Group BB: Beautifil-Bulk (SHOFU), Group BF: Beautifil-Bulk Flowable (SHOFU), and Group CO: "as a control group", Clearfil Majesty Posterior (KURARAY) and Group CF: "as a control group", Clearfil Majesty Flow + Clearfil Majesty Posterior (KURARAY). The restored teeth underwent an aging protocol involving 1000 cycles in a water bath fluctuating between 5 ± 1.0 °C and 55 ± 1.0 °C. Post-aging, teeth were immersed in 50% silver nitrate solution for 24 h and then in a film developer solution for 8 h. Microleakage analysis was performed using micro-CT, evaluated with 3D Slicer software. A two-way ANOVA was employed for statistical analysis. RESULTS: Two-way ANOVA results indicated significant effects of both viscosity (p < 0.0001) and composite type (p < 0.0001) on marginal adaptation. Viscosity analysis (comparing flowable and paste-like) revealed no significant differences in the FB-FF, XB-XF and BB-BF groups but significant differences in the and CO-CF group, with flowable type exhibiting less microleakage than paste-like type. CONCLUSIONS: The study suggests that while the viscosity of bulk-fill composites did not significantly affect marginal adaptation, the brand of bulk-fill composite did influence it.

Radiopacity of resin-based CAD/CAM blocks assessed by areal grayscale pixel value measurement.

PURPOSE: This study assessed radiopacity of resin-based computer-aided-design/computer-aided-manufacturing (CAD/CAM) materials by areal grayscale pixel value measurement. METHODS: Radiopacities of six resin-based CAD/CAM block materials and resin composite were evaluated and compared to that of enamel and dentin. Specimens of 1-mm thickness were placed on photostimulable phosphor plate and irradiated with digital x-ray unit. On the radiographic image, regions of interests were determined for each specimen and areal grayscale pixel values were measured. Elemental analysis was performed with energy-dispersive x-ray spectroscopy (EDS) on field emission scanning electron microscope (FESEM) images of the specimens. Data were analyzed statistically (α = 0.05). RESULTS: Radiopacity values of the restorative materials were significantly different from each other (P < 0.05). Radiopacity values of two resin-based CAD/CAM materials were significantly lower than that of dentin (P < 0.05). All tested restorative materials contain zirconium, three materials contain barium, and only resin composite contains lanthanum. CONCLUSION: Four CAD/CAM materials with higher amounts of zirconia or barium (>18%) had radiopacity values significantly higher than the dentin; while two materials with lower amounts of zirconia (<4%) and/or no-barium, had radiopacity values significantly lower than the dentin. EDS analysis suggests materials containing elements with higher atom numbers such as zirconia and barium could exhibit higher radiopacity.

Micro-computed tomographic evaluation of the effects of pre-heating and sonic delivery on the internal void formation of bulk-fill composites.

The aim of this study was to compare the effects of conventional, sonic or pre-heating insertion techniques on internal void formation of bulk-fill composites with micro-computed tomography. Standardized cylindrical cavities were prepared in 160 human third molars. Four groups received different paste-like bulk-fill composites: SonicFill 2 (SF2); VisCalor Bulk (VCB); Filtek One Bulk-fill restorative (FBF); Tetric EvoCeram Bulk Fill (TEB); and a conventional posterior composite, Clearfil Majesty Posterior (CMP). A hybrid CAD/CAM block was selected as a control (n=10). Composite restorations were built according to each resin composite type and insertion technique (n=10). Micro-CT was used to assess internal void rates. Data was analyzed with two-way ANOVA and Tukey's multiple comparisons test (α=0.05). CAD/CAM blocks were free of voids. For each composite, the highest void rates were observed for the sonic delivery method (p<0.05) except for SF2. SF2 was not affected by insertion techniques (p>0.05). Other composites showed the lowest void rates with pre-heating technique.

Child Abuse and Neglect Among Children Who Drop Out of School: A Study in Izmir, Turkey.

Child abuse and neglect (CAN), and dropping out of school have long been recognized as pervasive social problems globally, and Turkey is no exception. This study aims to explore the prevalence and incidence of CAN in children who drop out of school of Turkey, using the ISPCAN Child abuse Screening Tool, Children's Version, which is an appropriate tool for multinational comparisons. Data from a convenience sample of children who drop out of school age 11, 13, and 16 from Izmir were collected either by interviews or by self-completion. The results show that, compared to children who do not drop out of school, children who drop out of school have higher rates of psychological and physical abuse and neglect within the family. This study not only highlights the need for preventive laws for CAN and dropping out of school, but also points to direction for future research.

Epidemiological study of negative childhood experiences in three provinces of Turkey.

AIM: This study aimed to determine the frequencies of negative childhood experiences in the past years and negative childhood experiences throughout life in 11, 13 and 16 year-age group children who attended school in three separate provinces. MATERIAL AND METHODS: Approval was obtained from the provincial National Education Directorates and educated investigators applied the ISPCAN child abuse screening tool questionnaire form which measures negative childhood events experienced at home in children. Statistical analysis was performed with chi-square test using SPSS 16.0 program. Approval from the ethics committee was obtained from Izmir Tepecik Education and Research Hospital Chief Physician Office Local Ethics Committee (29/11/2011-29). RESULTS: The study was conducted with 7 540 children in Izmir, Denizli and Zonguldak. The frequency of psychological and physical negative childhood experiences and neglect throughout life was found to be 70.5%, 58.3% and 42.6% in the 11, 13 and 16-year age groups, respectively; the frequencies in the last one year was found to be 62.7%, 46.0% and 37.5%, respectively. Psychological negative childhood experiences were found with a higher rate in children who lived in urban areas compared to children who lived in rural areas. Neglect was found with a higher rate in girls and physical negative childhood experiences were found with a higher rate in boys. The frequency of negative childhood experiences increased proportionally with the age of the child independent of the type of experience. CONCLUSION: The frequencies of negative childhood experiences for the last one year and for the life-long period were determined using ISPCAN child abuse screening tool in Turkey for the first time in three provinces and in such a large population. The frequency of negative childhood experiences related with child abuse and neglect screened were found to be 42%-70% and it was elucidated that we are confronted with a very significant public health problem and adult health risk in these regions of Turkey.