7 research outputs found
Microshear Bond Strength of OptiBond All-In-One Self-adhesive Agent to Er:YAG Laser Treated Enamel After Thermocycling and Water Storage
Introduction: This study aimed to compare the microshear bond strength of composite to enamel treated with Erbium-Doped Yttrium Aluminum Garnet (Er:YAG) laser using a self-etch one step bonding agent.Methods: Seventy-six enamel surfaces were prepared from 38 sound human third molar teeth. Specimens were randomly divided into four groups of 18. The enamel surface in half the specimens was irradiated with Er:YAG laser. One extra specimen from each group was evaluated under a scanning electron microscope (SEM). Composite micro-cylinders were bonded to the specimen surfaces using OptiBond All-In-One (OB) adhesive agent and stored in distilled water for 24 hours. Half the specimens were thermocycled (2000 cycles) and stored in distilled water at 37°C for three months (TW). The microshear bond strength of composite to enamel was measured using a universal testing machine at a crosshead speed of 1 mm/min. The fractured surfaces were evaluated under a stereomicroscope at ×40 magnification to determine the mode of failure. Data were analyzed using repeated measures analysis of variance (ANOVA) and t test.Results: The mean values (±standard deviation) were 17.96 ± 2.92 MPa in OB group, 22.29 ± 4.25 MPa in laser + OB group, 18.11 ± 3.52 MPa in laser + OB + TW group and 9.42 ± 2.47 MPa in OB + TW group. Repeated measures ANOVA showed that laser irradiation increased the microshear bond strength (P < 0.001). Bond strength decreased when the samples were thermocycled and stored for three months (P < 0.001). The interaction effect of water storage and laser treatment on bond strength was significant (P < 0.05).Conclusion: Enamel surface preparation with Er:YAG laser is recommended to enhance the durability of the bond of self-etch bonding systems to enamel
Factors Associated with The Incidence of Coronary Heart Disease in The Mashad: A Cohort Study
Coronary heart disease (CHD) is the leading cause of morbidity and mortality globally, and specifically in Iran. Accurate assessments of Coronary heart disease (CHD) incidence is very necessary for public health. In current study we aimed to investigate the incidence of CHD and importance of several classical, modifiable and un-modifiable risk factors for CHD among an urban population in eastern Iran after 6 years of follow-up. Methods The population of MASHAD cohort study were followed up for 6 years, every 3 years in two step by phone and who reported symptoms of CVD were asked to attend for a cardiac examination, to estimate the incidence of CHD with 95% confidence interval (95% CI) as well multiple logistic regression analysis was performed to assess the association of several baseline characteristics with incidence of CHD event. Evaluation of goodness-of-fit was done using ROC analysis. CHD cases divided into four different classes which include: stable angina, unstable angina pectoris, myocardial infarction and sudden cardiac death. Results In the six years\u27 follow-up of Mashhad study, the incidence rate of all CHD event in men and women in 100,000 people-years with 95% confidence intervals were 1920 (810-3030) and 1160 (730-1590), respectively. The areas under ROC curve (AUC), based on multivariate predictors of CHD outcome, was 0.7825. Conclusion Our findings indicated that the incidence rate of coronary heart diseases in MASHAD cohort study increases with age as well as our final model designed, was able to predict approximately 78% of CHD events in Iranian population
Primary Intrarenal Neuroblastoma with Hypertension and Disseminated Intravascular Coagulation
The primary intrarenal neuroblastoma (IRNB) is a rare condition. Intrarenal neuroblastoma typically results from direct renal invasion from an adrenal neuroblastoma, but true intrarenal neuroblastoma originates either sequestered adrenal rests during the fetal life or intrarenal sympathetic ganglia. Clinical, radiological, and pathological correlation is very essential for diagnosis and appropriate management of this type of unusual cases. The distinction of this rare tumor from Wilms’ tumor is an important challenge since both tumors have major differences in prognostic and therapeutic response. We present a 3-year-old boy of primary intrarenal neuroblastoma with extensive abdominal and mediastinal mass, persistent hypertension, and disseminated intravascular coagulation (DIC)