@Article{, title={Measurement of water sorption of five different composite resin materials}, author={Waleed M. Khalil وليد خليل}, journal={Journal of baghdad college of dentistry مجلة كلية طب الاسنان بغداد}, volume={17}, number={3}, pages={37-41}, year={2005}, abstract={Background: Water sorption may affect composite resin materials by reducing their mechanical properties and wear resistance .The aim of this study is to measure the water sorption of five different composite resin materials, for different time intervals.Materials and methods: A stainless steel mold of 4 mm width, 8 mm length and 4 mm depth was constructed to form composite blocks. Seven blocks were made of each test resin composite material. All specimens were placed in a silica-gel desiccator for 48 hours. The samples were then weighed thrice using calibrated electronic microbalance, the average reading was recorded to the nearest 0.0001g. The specimens were kept in individual containers in deionized distilled water at 37 ºC.All specimens were periodically weighed. The weight measurements were taken at 2, 8, 14, 28,42,56,70,100,150 and 240 days intervals.Results: The statistical analysis of the results showed that all composite resin specimens continued to gain weight for a period of 28 days. After that period, the weight gain continued, although at a reduced rate. The changes after the 28 days period were small for the Herculite XRV, Tetric ceram and Tetric composite resins, and greater for the Filtek P60 and Composan LCM composite resins.Conclusion: In this study water absorption increased steadily for all materials. The percentage weight change showed a tendency to increase with the time of water storage. This study concludes that over a period of 8 months, the differences in water sorption capacity of the five composite resin materials are related to the differences in the amount of filler loading in the composite resin matrix. With one exception, the composite resin materials with the largest quantity of fillers had the least water sorption capacity after eight months of storage in water

} }