The effect of sodium hypochlorite on shear bond between composite and porcelain specimens

Abstract EN

Aim of Study : This in vitro study was conducted to evaluate the shear bond strength of intra oral por-celain repair system using 10 % sodium hypochlorite and different acid etch.

Materials and methods : Forty specimens were prepared in form of metal disks (8mm in diameter, 15mm height) and porcelain was applied according to the manufacturer instructions.

The specimens randomly divided into 4 equal groups.

In Group I, II the samples were treated with 9 % hydrofluoric acid for one minute.

While groups III, IV were treated with 37 % phosphoric acid for one minute, after washing the specimens with water and dryness, groups II, III the surfaces treated with 10 % sodium hypochlorite for one minute while group I and IV leaved untreated.

After that, the surfaces of all samples were washed and dried and silane coupling agent (MonoBond-S Vivadent, Liechtenstein) was applied according to the manu-facturer instructions, then bonding agent (Excite) (Vivadent, Liechtenstein) and composite (tetric N–ceram) (Vivadent, Liechtenstein) were applied according to the manufacturer instructions.

All the sam-ples were stored in normal physiological saline for 7 days.

Then the samples were the rmocycled ma-nually between two water baths After that Shear bond strength was tested using universal testing ma-chine.

Results : using ANOVA and Duncan’s multiple range tests.

The result showed that there was highly significant difference between groups treated with 10 % sodium hypochlorite with untreated one.

There was significant difference between samples acid etched using hydrofluoric acid with those etched with phosphoric acid.

Conclusions : Sodium hypochlorite and hydrofluoric acid significantly increase the shear bond strength between composite resin and porcelain fused to metal specimens.