الفهرس 
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Abstract
This study was conducted to evaluate the effect of (1) different doses of ionizing radiation, (2) aging on the microleakage of solvent-free self-etching adhesive. Class V cavity preparation were performed in forty bovine incisors and restored using nano-composite and solvent-free self-etching adhesive,.
Samples were randomly divided into 4 groups according to irradiation dose to 1) zero Gray, 2) 10 Gray, 3) 30 Gray, & 4) 60 Gray. Each group was measured for microleakage at three time intervals 1) 3 weeks, 2) 6 weeks and 3) 12weeks after the end of irradiation exposure.
Microleakage testing was performed using fluid filtration device. Furthermore, a sample of each group was micro-graphed using scanning electron microscopy. Values of microleakage in μl/min/20psi were collected and statistically analyzed.
Results showed that both the different irradiation dose and the aging of restoration affect the microleakage of solvent free self etching adhesive as there was statistically significant increase in microleakage between 3 weeks and 6 weeks in group 1 (control) and 3 (30 Gy), also at the 6 weeks there was a statistically significant difference between microleakage in group 2 (10Gy) and group 4 (60 Gy) at p≤ 0.05.
Conclusions:
Within the limitations of this study, the following conclusions could be drawn:
1- Different doses of ionizing radiation affect the microleakage of solvent-free self-etching adhesive.
2- Microleakage of solvent-free self-etching adhesive is affected by aging.
3- The aging of different doses of ionizing radiation seems to have erratic behavior in relation to the microleakage phenomenon.
4- The method of testing for irradiated samples seems to be unsatisfactory.
5- Radiation doses cause damage to the tooth structure.
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