Introduction: There is a significant relationship between polymerization rate and polymerization shrinkage stress in restoration. The more the polymerization rate is, the shorter viscoplastic phase of the composite would be, leaving no time for the composite to flow and consequently sudden hardening of the composite occurs. This leads into severe shrinkage stresses followed by composite detachment from cavity walls resulting in microleakage within restoration and tooth. The aim of this study was to suggest a new method of LIGHT EXPOSURE PATTERN for composite curing and evaluation of its effect on enamel and dentinal microleakage in respect to some other LIGHT EXPOSURE PATTERNs.Materials & Methods: In this exprimental invitro study, flat tooth sections, 40 dentinal and 40 enamel samples were etched and Dentin Bonding Agent (DBA) (Excite@) was applied according to the manufacturer's instruction. While placed on the samples, one bulk Tetric ceram@ A3 composite was inserted in to a 2x2 mm polyethylene cylindrical mould. Samples were divided into dentinal and enamel groups of ten and LIGHT cured with Astralis 7 LIGHT EXPOSURE PATTERNs including HIP (High Intensity Program), LOP (Low Intensity Program), PUL (Pulse Program) and SUP (Suggested Progressive Program) for 80 seconds. After curing, thermocycling, dye penetration and medial sectioning, samples were observed under a scaled reflective microscope for microleakage measurement. The data were analysed statistically using One-Way and Two-Way ANOVA and Duncan test through SPSS software.Results: There was a significant deference in microleakage between enamel samples. The microleakage rate was the highest in HIP group while no microleakage was detected in the other groups. The degree of microleakage in dentin samples was significantly less in SUP group than the others but there was no significant difference between the other groups. Conclusion: 1. The least dentinal microleakage occurred with application of suggested progressive program (SUP) compared to other testing groups.2. Like LOP and PUL LIGHT EXPOSURE PATTERNs, no enamel microleakage occurred with SUP application. 3. Enamel microleakage was detected in HIP group which had higher LIGHT intensity.  

Statement of Problem: Overcoming the side effects of polymerization phenomenon has provoked many researches to find out the solution. Since a desirable polymerization of composite resin is effective in success rate of restorations with these materials, and as there is a direct relationship between LIGHT intensity and desirable polymerization or curing depth, therefore it is expected that a suitable EXPOSURE PATTERN to produce a desirable curing depth to could overcome the side effects of polymerization phenomenon.Purpose: The aim of this study was to present a new LIGHT EXPOSURE PATTERN for composite curing and evaluation of its effect on microhardness and degree of polymerization of composite in respect to some other LIGHT EXPOSURE PATTERNs.Materials and Method: In an in vitro study, 4 groups of 5 brass cylinders were used and one bulky was filled with Tetric âCeram composite. Then samples in the first three groups were exposed 80 seconds to 3 types of Astralis 7@ LIGHT exposed PATTERNs, including: HIP (High Intensity Program), LOP (Low Intensity Program) and PUL (Pulse Program). The forth group was also exposed same time with SUP (Suggestive Progressive Polymerization) respectively.After sample preparation, they were analyzed with micro hardness tester in 6 different depths and dye penetration test was done for all samples and were evaluated by stereomicroscope. The data were analyzed statistically using One-way ANOVA and Duncan test through SPSS software.Results: In absence of depth factor consideration, the mean micro hardness in all four groups of EXPOSURE PATTERNs had no significant difference (p=0.362). The HIP, LOP, PUL, SUP LIGHT EXPOSURE PATTERNs produced significantly different micro hardness in 0-5 mm depth significantly (p=0.001). In other words there was a significant difference in micro hardness in different depths in each testing group. In the same depths, there was no significant difference in composite micro hardness between the 4 groups up to 4 mm depth, but at the depth of 5 mm in HIP group, micro hardness was significantly higher than the depth of 5 mm in the other group.Conclusion: The analyzes clarified that the suggestive LIGHT EXPOSURE PATTERN (sup) can control and guide the rate of polymerization along with having the same quality to the other LIGHT EXPOSURE patters in producing hardness up to the depth of 4 mm of composite restorations.

Introduction: The reaction of polymerization can be controlled by the LIGHT EXPOSURE PATTERN and the temperature. The purpose of this study was to evaluate the effect of different LIGHT EXPOSURE PATTERNs and composite temperatures on micro leakage of LIGHT cured composite resin restorations. Materials and Methods: In this interventional study, class V cavities were prepared on 200 extracted human molars. Then the teeth were randomly divided into four main groups according to different LIGHT EXPOSURE PATTERNs of High Intensity Program (HIP), Low Intensity program(LOP), Pulls Program(PUL) and Suggested Progressive Program(SUP) . and 5 subgroups according to different temperatures of composite during curing (5°c, 20°c, 35°c, 50°c and 65°c). After thermo cycling and dye penetration, measurement of micro leakage was done using a stereomicroscope. The data were analyzed using SPSS software (ANOVA).Results: ANOV A showed that both in enamel and dentinal margins, a significant decrease in micro leakage has occurred in SUP group. Micro leakage in enamel and dentinal margins was significantly higher in HIP group than the other groups. No significant difference was observed in the rate of micro leakage among the 5 subgroups with different temperatures.Conclusion: SUP LIGHT curing PATTERN could be considered for improving composite resin restorations as a superior LIGHT EXPOSURE PATTERN due to its ability in Polymerization control, reducing polymerization shrinkage stress and micro leakage. Prewar Ming of the composites is a practical and easy way to improve composite properties for dental restorations.

Statement of Problem: With more polymerization rate there would be less time for the composite to flow and consequently sudden hardening occurs. This leads into composite detachment from cavity walls resulting in micro leakage between the restoration and tooth, and will decrees the bond strength.Purpose: The aim of this study was to investigate the shear bond strengths of the enamel and dentin resin composite using Suggested Progressive program (SUP) and some other LIGHT EXPOSURE PATTERNs. Materials and Method: In this experimental in vitro study, the test groups were composed of 40 dentinal and 40 enamel samples prepared on facial surfaces of 80 human canine teeth. 2x2mm polyethylen cylandric molds were filled in bulk with Tetric Ceram composite and were placed on the prepared surfaces. Irradiation PATTERNs for 4 groups of 10 dentinal and 10 enamel samples were as follows: Group 1, HIP (High Intensity Program). Group 2, LOP (Low Intensity Program). Group 3, PUL (Pulse Program) of Astralis 7 LIGHT curing unit EXPOSURE PATTERNs, and Group 4, SUP (Suggested Progressive Program). After curing and 24 hours incubation in 37°c, the samples were thermocycled under 500 cycles (5-55°c), and mounted with acrylic resin. Shear bond strengths of all samples were obtained using the Instron testing machine with 0.5 mm/min crosshead speed. For statistical analysis, one way and two way ANOYA and Duncan testes were used by SPSS software. Results: There was no significant difference between the shear bond strengths of four LIGHT EXPOSURE PATTERNs in dentinal and enamel groups (p<0.001). It was also revealed that various LIGHT EXPOSURE PATTERNs had no significant effect on shear bond strength of composite to enamel and dentin (p=0.388).Conclusion: SUP LIGHT EXPOSURE PATTERN has the same capability of producing appropriate bond strength with the tooth structures as other LIGHT EXPOSURE PATTERNs.

Introduction: Academic faculty members need to emphasize ethical principles in order to improve higher education, with the understanding of this importance, the current research was conducted with the aim of designing the ethical model of academic faculty members in Iran's higher education. Material & Methods: This research is a type of qualitative study that uses foundational data theory. The participants, including experts and faculty members of the country's public universities, who were responsible for the promotion of academic members, were selected as key informants through a targeted sampling method of 45 people. Data were collected through semi-structured interviews. The reliability and validity of the data were obtained from the two methods of reviewing the participants and recoding by experts. Data were analyzed by open, central and selective coding. Results: The results showed that the moral model of faculty members in Iran's higher education is explained in 10 main categories and 27 subcategories. Major and core categories in the form of 6 dimensions of causal conditions including (individual factors, organizational factors), core (cultural-educational, educational ethics, research ethics, scientific-executive), background conditions (higher education policies, moral activism), intervening conditions (environmental factors), strategies (micro level-university, macro level-higher education) and consequences (individual and organizational) were elevated to a higher abstract level and finally the research paradigm model was presented. Conclusion: The regulations for the promotion of academic staff members in Iran require a detailed revision of the content with an ethical and qualitative approach in order to make the indicators of the promotion regulations efficient and effective.

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Introduction: Steel industries are one of the major needs of the country. Noise pollution in steel production operations is an occupational hazard because of special equipment such as electric arc furnaces. The aim of this study was to evaluate noise pollution in various units of a steel company for determining the occupational EXPOSURE PATTERN.Methods: This was a cross-sectional and analytical noise pollution study in various units of a steel company in Iran (Hamadan state). The sound pressure levels were measured in accordance with the ISO-9612 standard and using the Casella-Cel model 450 sound level meter on “A” frequency weighing and the “slow” mode for time response. The frequency analysis in one octave-band was done with measures on “C” frequency weighing. We used the Surfer V.10 software for interpolation and noise maps producing. Microsoft Office Excel 2010 software was used for graph drawing. Noise dosimetry was performed using model TES-1345 dosimeter.Results: The results of this study showed that 56% of the total measurement stations were in the danger zone [above 85 dB (A)]. The maximum sound levels in the areas of electric arc furnaces and ladle furnace were recorded 112.2 dB (A) and 97 dB (A), respectively. The averages of the noise dose in three occupational groups of industrial cleaner, melting and casting were 2133%, 514%, and 577%, respectively. The dominant frequencies recorded in two central frequencies were 125 Hz and 250 Hz, respectively.Conclusions: According to the results, occupational EXPOSURE to noise in all the units indicated a dominant frequency of less than 500 Hz and could not be protected by hearing protection devices. The noise doses were over 500% and the time EXPOSURE shifts could not be reduced. Therefore, performing technical control plans are of priority in this industry.

Background: The need for a rapid, noninvasive method for unwanted hair removal has led to the development of various LIGHT sources for this purpose. Objective: To evaluate the efficacy of Intense Pulsed LIGHT Source (IPLS) on unwanted hairs. Patients & Methods: In this open, uncontrolled clinical trial, 77 different anatomical areas in 34 referred patients to "Novin Didegan Clinic" in Tehran in 1380-1381, were treated by IPLS at fluencies ranging from 22 to 34 j/cm2 after their demographic data and the number of hairs were recorded. The 3 to 7 treatment sessions were accomplished 4 to 6 weeks apart. All of the patients were followed 6 months after the last therapy. The quantitative data were  analyzed by paired t test. Results: Six months after the last therapy, more than 50% reduction in number of hairs was noted in 80% of the treated areas; with mean reduction of 72±23 percent. Side effects were mild and reversible and occurred in ten patients. Conclusion: The IPLS appears to provide an effective and safe method for long term excess hair removal in various skin types.