ABSTRACT
STATEMENT OF PROBLEM: Resin composites are brittle materials and their major shortcomings are manifested in their sensitivity to flaws and defects. Although various mechanical properties of resin composites have been described, few studies are available on assessing the effect of bleaching agents on resin composites using the short rod design. PURPOSE: To place various resin composites into distilled water at 37°C for 21 days and determine the effect of immersion time in distilled water, with and without exposure to 10% carbamide peroxide by employing short rod design fracture toughness test. MATERIALS AND METHOD: Specimens were prepared from three resin composites; Rok (SDI), Esthet (Dentsply), and Estelite (Tokuyama). For each material, a total of 24 disc-shaped specimens were prepared using a custom-made mould. Specimens were randomly divided into 3 groups of 8 and conditioned in 37°C distilled water for either 24 hours, or 21 days. 21 day specimens were tested both with and without applying bleaching agent; Polanight (SDI). Study group specimens were bleached for 21 days, 2 hours a day. The specimens were loaded using a universal testing machine with a crosshead speed of 0.5 mm per minute. The maximum load at specimen failure was recorded and the KIc (MPa. M (0.5)) was calculated. RESULTS: Statistical analysis using two-way ANOVA showed a significant relationship between material and time (p< 0.05).Tukey's test showed that after 24 h of immersion in distilled water, Rok revealed the highest KIc followed by Esthet and Estelite. The bleaching agent significantly improved the fracture toughness values of Esthet while it decreased that of Estelite. CONCLUSION: The fracture toughness of the resin composites was affected by the bleaching agent and distilled water. In comparison with Rok and Estelite, fracture toughness of Esthet was increased due to aging and application of bleaching agent.
ABSTRACT
This study was designed to estimate the burden of urologic diseases in the Islamic Republic of Iran as a practical method for defining public health priorities. Using World Health Organization guidelines for national burden of disease studies, 6 steps were performed: selecting diseases to include; dynamic modelling of diseases; gathering data about urologic diseases; computing the local disability weights of urologic diseases; data analysis with DisMod II; and computing the disability-adjusted life years for each disease. Renal calculus, acute cystitis, chronic prostatitis, benign prostate hyperplasia, male infertility and adult polycystic kidney disease comprised the greatest burden
Subject(s)
Health Priorities , World Health Organization , Disability Evaluation , Consensus , Urologic DiseasesABSTRACT
We carried out a cross-sectional study with cluster random sampling to study the status of wife abuse in Esfahan from April to July 2002. We interviewed 386 married women using a standard questionnaire. Mean age was 35.7 years [range 15-78 years]. Prevalence of wife abuse was 36.8%; incidence was 29.3%. Types of abuse included inattention to wife's feelings 44.8%, threatening to prevent communicating with the wife's family 38.1%, slapping 31.9% and beating 27.2%. Husband's age, use of drugs or alcohol, smoking, income and number of children were all associated with wife abuse [P < 0.05]. We recommend further investigation to detect the risk factors for wife abuse in this community along with mass education concerning sexual responsibility and conduct towards wives. We also advocate the promotion of supportive measures for abused women
