Cytogenetic abnormalities in 222 infertile men with azoospermia and oligospermia in Iran: Report and review.

Background: Infertility affects approximately 10%-15% of couples in reproductive age. In half of the couples, causes are male-related, associated with impaired spermatogenesis. There is a complex correlation between genetics and infertility. Several factors affect on gametogenesis, from which factors that lead to chromosomal abnormalities are one of the best known. The aim of this study was to determine type and rate of chromosomal abnormalities in infertile azoospermic and oligospermic males in Iranian population. Materials and Methods: The records of a total of 222 participants were evaluated retrospectively. Results: As a whole we observed 13.96% chromosomal abnormality, from which 12.15% showed numerical and 1.8% showed structural abnormalities. Conclusion: Comparison of our results with the review of the literature shows a higher incidence (4- fold) of gonosomal, in particular, numerical gonosomal, chromosomal anomalies. Cytogenetic analysis is strongly suggested for infertile men, particularly in those who suffer from azoospermia.

[Combined effect of saturated fat and cholesterol intake on serum lipids of urban tehranians: tehran lipid and glucose study [TLGS]]

Despite many studies on the effect of saturated fat and cholesterol intake on serum lipids, data on the combined effect of these two dietary components on serum lipoprotein response is very limited. In this study, a representative sample of 443 subjects, aged 18 years and over, were included. Dietary intake was assessed by means of two 24-hour dietary recall questionnaires. Height and weight were measured and BMI was calculated. Total cholesterol, triglycerides and high density lipoprotein cholesterol levels were measured and serum cholesterol was calculated. Cholesterol intake 2:300 mg/day was defined as high cholesterol intake, and saturated fat intake 37% of total energy was defined as high saturated fat intake. Individuals were categorized into 4 groups, based on cholesterol and saturated fat intake; each of these was assessed for 2 levels of serum lipids, normal and high. Pearson's correlation coefficient was used to detect confounding variables. Two-Way ANOVA was used to determine both the main effect of each of the two factors on lipids and their combined effect as well. Mean age of subjects was 40.1 +/- 14.6 y. The main effect of cholesterol and saturated fat intake on energy intake was significant. Subjects in whom cholesterol and saturated fat intake was normal had significantly less energy and fat intake than those who had high cholesterol and saturated fat intake [p<0.01]. Saturated fat intake was seen to have a significant main effect on serum total and HDL cholesterol levels. Subjects who had a normal saturated fat intake, had significantly less serum total and HDL cholesterol than those who had high saturated fat intake [p<0.01 and p<0.05, respectively]. Adjusted for age, sex and BMI, the main effect of cholesterol intake on HDL cholesterol was significant [p=0.05]. Mean serum HDL was lower in subjects who had normal cholesterol intake than in subjects who had high cholesterol intake. The present study shows that cholesterol and saturated fat intake had no combined effect on serum LDL cholesterol level, whereas cholesterol intake per se did affect serum HDL cholesterol level

Evaluat of temperature rise with different curing methods and units in two composite resins

The majority of commercial curing units in dentistry are of halogen lamp type. The new polymerizing units such as blue LED are introduced in recent years. One of the important side effects of light curing is the temperature rise in composite resin polymerization which can affect the vitality of tooth pulp. The purpose of this study was to evaluate the temperature rise in two different composite resins during polymerization with halogen lamps and blue LED. This experimental study investigated the temperature rise in two different composites [Hybrid, Tetric Ceram/Nanofilled, Filteke Supreme] of A2 shade polymerized with two halogen lamps [Coltolux 50, 350 mW/cm2 and Optilux 501 in standard, 820 mW/cm2 and Ramp, 100-1030 mW/cm2 operating modes] and one blue LED with the intensity of 620 mW/cm2. Five samples for each group were prepared and temperature rise was monitored using a k-type thermocouple. Data were analyzed by one-way ANOVA, two-way ANOVA and Tukey HSD tests with P<0.05 as the limit of significance. Light curing units and composite resins had statistically significant influence on the temperature rise [p<0.05]. Significantly, lower temperature rise occurred in case of illumination with Coltolux 50.There was no significant difference between Optilux 501 in standard curing mode and LED. Tetric Ceram showed higher temperature rise. According to the results of this study the high power halogen lamp and LED could produce significant heat which may be harmful to the dental pulp

Effect of three filler types on mechanical properties of dental composite

Despite the improvements achieved in the field of dental composites, their strength, longevity, and service life specially in high stress areas is not confirmed. Finding better fillers can be a promising step in this task. The purpose of this study was to investigate the effect of the filler type on the mechanical properties of a new experimental dental composite and compare these with the properties of composite containing conventional glass filler. Experimental composites were prepared by mixing silane-treated fillers with monomers, composed of 70% Bis-GMA and 30% TEGDMA by weight. Fillers were different among the groups. Glass, leucite ceramic and lithium disilicate were prepared as different filler types. All three groups contained 73% wt filler. Comphorquinone and amines were chosen as photo initiator system. Post curing was done for all groups. Diametral tensile strength [DTS], flexural strength and flexural modulus were measured and compared among groups. Data were analyzed with SPSS package using one-way ANOVA test with P<0.05 as the limit of significance. Results: The results showed that the stronger ceramic fillers have positive effect on the flexural strength. Ceramic fillers increased the flexural strength significantly. No significant differences could be determined in DTS among the groups. Flexural modulus can be affected and increased by using ceramic fillers. Flexural strength is one of the most significant properties of restorative dental materials. The higher flexural strength and flexural modulus can be achieved by stronger ceramic fillers. Any further investigation in this field would be beneficial in the development of restorative dental materials

Effect of filler type on 3-body abrasion of dental composite

The relatively poor wear resistance of dental composite in stress bearing posterior situations has restricted wider clinical application of this restorative material. The aim of this study was to evaluate the three body abrasive wear of a dental composite based on a new filler [leucite: KAl Si2O6] and to compare it with the wear resistance of a composite based on commonly used Aluminium - Barium Silicate filler. This research was an interventional study done in Iran polymer institute. Five specimens were considered in each group. All ceramic IPS Empress [R] [Ivoclar- Vivadent] ingots based on leucite crystals were ball milled, passed through an 800 sieve and used as filler. Experimental composites were prepared by mixing the silane- treated fillers with monomers [BisGMA and TEGDMA]. Camphorquinone and amine were used as photoinitiator system. Degree of conversion of the light-cured and post-cured composites was measured using FTIR spectroscopy. The prepared pastes were inserted into plexy-glass mold and light cured [700 mw/cm[2], 40 s]. Then for maximum degree of conversion specimens were post- cured [120°C, 5 hours]. Three body abrasion wear testing was performed using a wear machine with 50 rpm rotational movement. In this machine, pumice [150 meshes] was used as the third body. Weight loss of specimens in each group was measured by balance after each 50 hours. After wear testing SEM examination was made specimens in each group. The data were analyzed and compared using ANOVA and Tukey HSD tests [P<0.05]. Tetric Ceram was tested as commercial composite. There were significantly differences between three body abrasive wear of composites. The ranking from lowest to highest was as follows: leucite composite [19%] < Tetric Ceram [22%] < glass composite [28%]. leucite composite showed the highest wear resistance value, propably due to the crystalliniy and hardness of filler. Introduction of this new filler as an alternative to glass filler, significantly increases the wear resistance of the resin composites. Further investigations on mechanical properties of new composites would be beneficial in the development of new dental materials