Background and Aims: Micro leakage is a criterion proposed for assessing the success of any restorative material. Complete seal is difficult especially for dentin margins compared to enamel margins. The aim of this study was to assess the micro leakage at the enamel and dentin margins of class V cavities restored by two GIs and two self-etch adhesive systems.Materials and Methods: This study was done on forty third molars. Class V cavities (3´2´2mm) were prepared on the buccal and lingual surfaces of teeth using high speed handpiece with 0.8 mm diamond fissure burr. The occlusal margins of the cavities in the enamel and gingival margins were placed 1 mm below the CEJ. The teeth were divided into 4 groups and the bondings were cured for 20 sec and the teeth were restored. The specimens were kept in distilled water at the temperature of 37°C for 24 hrs. The teeth were thermo cycled and cut in buccolingual direction using diamond disc under water. The dye penetration was evaluated using a stereomicroscope and the leakage was scored. The scores were compared using Kruskal-Wallis test while the paired comparisons were done using Bonferroni correction. P≤0.05 was regarded as significant results.Results: Micro leakage scores were similar at the occlusal and gingival walls of all test groups. At the gingival walls, the least micro leakage scores were observed. “Fuji IX + SE bond” group showed significant differences with the “Fuji IX + G bond” and “Nano GLASS + G bond” groups (P£0.05). At the occlusal walls, the least scores were observed in the “Fuji IX+SE bond” specimens which were significantly different from the other groups (P£0.05).Conclusion: Self-Cure GLASS ionomers yielded less micro leakage scores compared to the different types of light-cures due to the less polymerization shrinkage.

Given the problems and disadvantages of fiberGLASS vessels during and after the construction and during the operation at sea, this paper first examines the problems in manufacturing process and suggests appropriate solutions and strategies for solving them. Then, issues like repairmen and inspection are assessed. Advantages of fiberGLASS vessels over others are also presented.

In this research, in order to study effects of fabrication method the square-shaped bistable composites laminates with asymmetric layers were prepared and investigated. Different kinds of bistable composite laminates were fabricated by thermoplastic PVC and GLASS fibers and the effects of composites laminate dimensions and MOLD temperature were investigated. The maximum height of the bistable composite laminate is selected as the output of experiments. The results derived from ANOVA analysis showed that the dimensions of the laminates have the highest effects on bistability height and the effects of MOLD temperature are very low. It was also determined that with the larger dimensions of composite laminates and lower MOLD's temperature, the heights of bistability were higher. Also, these bistable composite laminates were simulated in ABAQUS and the simulation results were compared with the experimental results. The results indicated that simulation method anticipated the higher bistability height rather than the experimental results and the difference between these results is less than 10% in all specimens.

Today, in addition to the durability properties of concrete, its aesthetic qualities and appearance are also being researched and examined. The appearance of concrete depends on the type of concrete, the characteristics of the materials, the method of construction, and the curing process. Among the various parameters affecting the aesthetic appearance of concrete during construction, the type of formwork, the type of release agent used, and the curing conditions are significant factors. The main objective of this research is to investigate the parameters of formwork type, curing conditions, and type of release agent on the surface quality of concrete. In this context, various samples were produced using self-compacting concrete with ABS, PVC, untreated wooden, MDF, and metallic formworks, utilizing two types of release agents based on water and petroleum solvents, or with no release agent at all. Two curing conditions were also examined: curing in water and curing in an environment outside water. Different tests, including water absorption, abrasion, Schmidt hammer, and water droplet penetration tests, were conducted. The water droplet test was proposed and examined for a rapid assessment of the aesthetic quality of concrete. Test results show ABS and PVC samples perform well under various conditions. ABS with solvent-based MOLD oil resists water absorption, while PVC with water-based oil shows good impact resistance. ABS with water-based oil excels in compressive strength. Samples without MOLD oil have better surface quality. Non-water-cured samples offer superior aesthetics, while water-cured ones have enhanced physical properties due to higher density. Material choice and manufacturing conditions significantly impact product quality, aiding production optimization.