Shear bond strength of metal brackets to ceramic surfaces using a universal bonding resin

Assure Plus is a recently introduced universal adhesive with the ability to bond to various restorations. This study compared the shear bond strength of brackets bonded to two types of ceramics using conventional bonding agent and Assure Plus. Surface damage caused by debonding was also evaluated. In this in vitro study, 40 feldspathic and lithium disilicate ceramic discs were sandblasted, etched with 9.6% hydrofluoric acid and divided into two groups. In group 1, silane was applied and air-dried followed by application of Transbond XT primer, which was light-cured. In group 2, Assure Plus was applied and air-dried. In both groups, maxillary central incisor brackets were bonded. After incubation in distilled water at 37°C for 24 hours and 2000 thermal cycles, bond strength was measured using a universal testing machine, and the adhesive remnant index (ARI) and failure modes were determined. ANOVA and LSD tests were used to compare bond strength values; chi-squared test was used to compare ARI scores. Bracket bond to lithium disilicate by Assure Plus was significantly stronger than that to Feldspathic porcelain (P=0.041). Only in the Assure Plus/lithium disilicate group did some adhesive remain on the surface following debonding (40% of samples, P<0.05). Cohesive porcelain fracture had the lowest frequency in the lithium disilicate/Assure Plus group. Assure Plus provided high bond strength between ceramic and brackets and minimized damage to lithium disilicate ceramic during debonding. Assure Plus is recommended for use in orthodontic treatment of adults with ceramic restorations

Using different definitions affected the reported prevalence of neurodevelopmental impairment in children born very preterm

AimWe investigated the impact of varying definitions on the prevalence of neurodevelopmental impairment (NDI) in children born very preterm at 6.5 years of age.MethodsCognitive development and neurosensory impairments were assessed in 91 children (40/51 girls/boys) born ResultsThe prevalence of severe NDI varied from 2% to 23% depending on the definition used. The prevalence of cognitive impairment varied from 2% (−3 SD according to test norms) to 16% (−2 SD according to control group), the prevalence of cerebral palsy from 0% (severe) to 9% (any) and the prevalence of severe visual impairment from 0% (blindness) to 1% (visual acuity ConclusionA high variability in definitions affects the reporting of the prevalence of NDI in long-term follow-up studies of very or extremely preterm born children. There is a need for a better consensus to enable comparisons across studies.</p

Correlation of dental age estimated by Moorrees and Demirjian methods with chronological age in orthodontic patients

Background: Dental age determination has been considered for malocclusion treatment planning by Orthodontists and Pediatric Dentists. Objective: The aim of this study was to compare the correlation of dental age estimated by Demirjian and Moorrees methods with chronological age in the orthodontic patients. Methods: In this analytical study, 419 panoramic images of 6-15 years old orthodontic patients referred to School of Dentistry in Qazvin were assessed in 2013. Dental age was estimated by Moorrees et al. (1963) and Demirjian et al. (1973) methods through the calcification stages of the left mandibular teeth with the exception of the third molar. Data were analyzed using paired T-test and Pearson’s correlation coefficient. Findings: Of 419 patients, 190 (45%) were male and 229 (55%) were female. The mean age was 11.26±2.47. Although there were positive significant correlations between the methods in all study subjects, the Moorrees dental age was significantly different from the chronological age in all age groups. The Demirjian dental age was significantly different from chronological age in the 6-year old age group and 7, 12 and 15-year old males. There were significant differences between the Moorrees and Demirjian dental age in all age groups. Conclusion: With regards to the results, it seems that the Moorrees method is not appropriate for Iranian population while the Demirjian method can be acceptable for estimation of dental age based on chronological age. Due to the overestimation found in the Demirjian method, exclusive tables must be prepared for Iranian population. Keywords: Age Determination by Teeth, Moorrees Method, Demirjian’s Metho

Average 2.5-year neurodevelopmental test results in children born very preterm did not rule out cognitive deficits at 6.5 years of age

Aim The aim of the study was to investigate cognitive outcomes at 6.5 years in children born very preterm, in relation to neonatal characteristics and 2.5-year neurodevelopment. Methods A prospective cohort, with gestational age 22.3-31.9 weeks, born 2004-2007, were examined at 2.5 years with the Bayley Scales of Infant and Toddler Development (Bayley-III) (n = 100) and at 6.5 years with the Wechsler Intelligence Scales (n = 91). Results Neonatal factors independently related to 6.5-year outcome were gestational age, retinopathy of prematurity and treated persistent ductus arteriosus. The Bayley-III cognitive scores explained only 44% of the Full-Scale Intelligence Quotient result at 6.5 years, and 22% of the children had Wechsler index results below −1 SD, indicating cognitive impairment, after average test results at 2.5 years. The relative risk to score below −1 SD on the Full-Scale IQ was 2.83 (95% CI 1.45-5.53) in children with gestational age below 28 weeks and 2.22 (95% CI 1.18-4.17) at gestational age 28-31 weeks. Conclusion Very preterm infants born in the 2000s had increased risks for impaired cognition at 6.5 years, but individual predictions based on neonatal risks and 2.5-year test results were not enough to identify all high-risk children

Brain Extraction Methods in Neonatal Brain MRI and Their Effects on Intracranial Volumes

Magnetic resonance imaging (MRI) plays an important role in assessing early brain development and injury in neonates. When using an automated volumetric analysis, brain tissue segmentation is necessary, preceded by brain extraction (BE) to remove non-brain tissue. BE remains challenging in neonatal brain MRI, and despite the existence of several methods, manual segmentation is still considered the gold standard. Therefore, the purpose of this study was to assess different BE methods in the MRI of preterm neonates and their effects on the estimation of intracranial volumes (ICVs). This study included twenty-two premature neonates (mean gestational age ± standard deviation: 28.4 ± 2.1 weeks) with MRI brain scans acquired at term, without detectable lesions or congenital conditions. Manual segmentation was performed for T2-weighted scans to establish reference brain masks. Four automated BE methods were used: Brain Extraction Tool (BET2); Simple Watershed Scalping (SWS); HD Brain Extraction Tool (HD-BET); and SynthStrip. Regarding segmentation metrics, HD-BET outperformed the other methods with median improvements of +0.031 (BET2), +0.002 (SWS), and +0.011 (SynthStrip) points for the dice coefficient; and −0.786 (BET2), −0.055 (SWS), and −0.124 (SynthStrip) mm for the mean surface distance. Regarding ICVs, SWS and HD-BET provided acceptable levels of agreement with manual segmentation, with mean differences of −1.42% and 2.59%, respectively

Using different definitions affected the reported prevalence of neurodevelopmental impairment in children born very preterm

Aim We investigated the impact of varying definitions on the prevalence of neurodevelopmental impairment (NDI) in children born very preterm at 6.5 years of age. Methods Cognitive development and neurosensory impairments were assessed in 91 children (40/51 girls/boys) born &lt;32 gestational weeks, in 2004-2007 in Uppsala county, Sweden. The results were compared with data from a reference group of 67 children born full term. The prevalence of NDI in the present cohort was reported according to definitions used by seven contemporary studies of children born very or extremely preterm. Results The prevalence of severe NDI varied from 2% to 23% depending on the definition used. The prevalence of cognitive impairment varied from 2% (−3 SD according to test norms) to 16% (−2 SD according to control group), the prevalence of cerebral palsy from 0% (severe) to 9% (any) and the prevalence of severe visual impairment from 0% (blindness) to 1% (visual acuity &lt; 0.3). There were no children with severe hearing impairment. Conclusion A high variability in definitions affects the reporting of the prevalence of NDI in long-term follow-up studies of very or extremely preterm born children. There is a need for a better consensus to enable comparisons across studies

Quality of Life and Stigma Among People Living with HIV/AIDS in Iran

Background: Stigma against HIV profoundly affects the quality of life (QOL) of people living with HIV/AIDS (PLWHA). We aimed to assess the factors associated with QOL in PLWHA in Iran, specifically HIV-related stigma, sociodemographic and clinical characteristics. Methods: Two hundred PLWHA participated in this cross-sectional study. Data were collected using sociodemographic, stigma, and WHO-QOL-BREF questionnaires. Correlations, ANOVAs, and Student’s t-distribution tests were performed as bivariate analyses. We employed stepwise multiple linear regression analysis to explore the main factors associated with QOL domains. Results: Six domains of QOL were negatively correlated with three domains of stigma (p \u3c 0.001 for all). Stepwise multiple linear regression revealed that, after adjusting for con-founders, lack of healthcare insurance, having no basic knowledge of HIV/AIDs prior to diagnosis, low monthly income of participants and family, and stigma (blaming and distancing, discrimination, and fear) were associated with low mean score of different domains of QOL. Conclusion: Our findings indicated that increasing HIV/AIDS-related stigma decreases QOL in PLWHA in Iran. Attention toward decreasing stigma, improving healthcare plan, and cultivating economic condition should be given high priority to ensure improvement in total QOL and corresponding domains in PLWHA’s life