Abstract
To evaluate the shear bond strength of intra oral porcelain repair system using different surface
treatments when fracture of porcelain with complete metal exposure. Materials and Methods: forty
specimens were prepared in form of metal disks (8mm in diameter, this diameter is for each specimen
and 15mm height) and randomly divided into 4 equal groups. The first two groups were treated with air
abrasion. The other groups leaved untouched. Groups I and III were treated with 37% phosphoric acid
while in groups II and IV the surface were treated with 9% hydrofluoric acid, after that the surfaces of
all samples were treated with silane coupling agent then bonding and composite were applied according
to the manufacturer instructions. All the samples were stored in a normal physiological saline for 7
days. Then the samples were thermocycled after that Shear bond strength was tested using universal
testing machine. Results: The result showed that there was a highly significant difference between
groups treated with Al2O3 with those untreated one, the acid etch material. There was a highly significant
difference between samples acid etched using hydrofluoric acid with those etched with phosphoric
acid. Conclusion: Air abrasion and the hydrofluoric acid significantly increase the shear bond strength
between composite resin and exposed metal of metal ceramic restoration.
