(The Effect of Air Abrasion on the Strength of Resin Repaired Fiber Reinforced Composite Restorations (In-vitro Study

Abstract

Fiber reinforced composite restorations are promising altern atives to all ceramic and ceramometa lli c restoration s. repair of minor defects of the veneer in g materia l, can save the restoration from replacement .

This study was d esign ed to measure the shear bond strengt h of resin repaired Targis/ Vectris rest o rat ion s after u sing three different a ir abrasio n pressmes as a surface treatment.

The Fracture strengt h of umepa ired Targis/Vectris crowns was measured and compared to the fracture strengt h of standardizedly repaired crowns using th e most appropri ate and selected pressure for su rface treatment of the repair site. This was done to co mpare the effect of the repair procedures on the fracture strength ofTargi s/Vectris crow ns.

50 standardi zed Targis/Vectris discs were fabricated and classified according to surface treatment protocol. Sampl es were classified in to 5 groups ( l 0 samples e<Jch ). Group: A: con trol group, Targis/Vectris sa m ples, Group 8: no air abrasio n trea tment samp l es, Group C: a ir abraded samples usin g 40 ps i., Group 0: air abraded samples using 60 psi., and Group E : air abraded samples us in g 80 psi.

Different air abrasion pressures were ap plied at a fixed distance of 2 cm . for 5 seconds, using a specially designed ho ld er.

Repair material was applied in a standardized form using a speci ally designed teflon mold (mold 2). To simu late conditions in the oral environmen t, each group was subdiv id ed into 2 subgroups (5 samples each ).