Lamia N. Metwally , Mokhtar N. Ibrahim , Omaima H. Ghallab And Amin E. Amin,

ABSTRACT

Objectives: To Evaluate The Effect Of Different Doses Of Ionizing Radiation And Storage Times On The Microleakage Of Two Different Types Of Glass Ionomer Restorative Materials; Conventional And Resin Modified.

Materials and Methods: Standardized Cylindrical Class V Cavities Were Performed In 80 Bovine Incisors. Teeth Were Divided Into Two Main Groups According To The Type Of The Glass Ionomer Material Used Restoring The Cavities; Conventional Or Resin Modified (n=40). Both Groups Were Further Divided Into Four Subgroups According To Irradiation Dose; Zero Gray (control Group), 10 Gray, 30 Gray And 60 Gray (n=10). Each Group Was Measured For Microleakage At Three Time Intervals; 3 Weeks; 6 Weeks And 12 Weeks After The End Of The Radiation Exposure. Microleakage Testing Was Performed Using Fluid Filtration Device. Values Of Microleakage In �l/min/20 Psi Were Collected, Tabulated And Statistically Analyzed. Data Was Presented As Mean And Standard Deviation Values, The Significant Level Was Set At P �0.05.

Results: Mixed Model ANOVA Showed That The Groups Of (control And 10 Gray) Had Statistically Significant Lower Microleakage Values Than (30 Gray And 60 Gray) Groups (p<0.05). There Was A Statistical Significant Effect Of The Type Of Glass Ionomer On The Microleakage. The Interaction Between The Storage Times, The Type Of Glass Ionomer And The Irradiation Doses Was Only Significant In 60 Gray Group P=0.038 For The Conventional Glass Ionomer Group And P=0.014 For The RMGI Group).

Conclusions: Within The Limitations Of This Study, It Was Concluded That: The Time Of Storage Didn?t Have Any Influence On The Microleakage Of Class V Glass Ionomer Restorations. The Variation Of The Chemical Composition Of Glass Ionomer Affected The Microlekage Of Class V Glass Ionomer Restorations And The High Therapeutic Radiation Doses Had A Direct Effect On The Microleakage Of Class V Glass Ionomer Restorations.