An in vitro Comparison of Microleakage in Composite Inlays with Two Different Methods of Surface Treatment

In order to establish micromechanical retention، the internal surface of indirect composite restoration must be made before submitted to treatment. The aim of this in vitro investigation was to compare of microleakage in direct composite inlay restoration between two different surface treatments. Using 75 extracted non-carious human premolars، following cavity preparation، all samples were restored by composite inlays after removal of inlays. The samples were randomly divided into 3 groups (n=25)، according to the following surface treatment sand blasting with 50 m Al2O3 particles، etching with 9. 5 % hydrofluoric acid and non-treated control groups. All inlays were cemented to the tooth cavities with dual cure cement. The samples were thermocycled (500 cycles at 5-55C)، sectioned and extent of dye penetration at gingival margins was scored be two independent operators. The data were statically analyzed with Kruskal Wallis and Mann-Whitney tests. Air abrasion resulted in a significant decrease in microleakage among all groups (P=0. 030). Sand blasting led to less microleakage compared to hydrofluoric acid treatment (P=0. 0385) and control (P=0. 008). No significant difference was observed between hydrofluoric acid and control group. Sand blasting resulted in a significant reduction in microleakage، in composite inlays.