Shear bond strengths of composite bonded to porcelain using porcelain repair systems.

PURPOSE

To measure and compare the shear bond strengths to porcelain of two composites used with each of two different porcelain bonding systems.

METHODS

40 porcelain specimens were mounted in acrylic resin, ground flat using 120 and 320 grit sandpaper, and randomly divided into four groups of 10 for specimen fabrication as follows: Group 1: Premier MicroDose Porcelain Bonding/Optibond FL adhesive/Prodigy composite; Group 2: Premier MicroDose Porcelain Bonding/PQ1 adhesive/Amelogen composite; Group 3: Ultradent Porcelain Etch/Optibond FL adhesive/Prodigy composite; Group 4: Ultradent Porcelain Etch/PQ1 adhesive/Amelogen composite. Manufacturers' directions were followed to treat the porcelain surface and apply the adhesive and composite to each specimen. Following storage in distilled water at 37 degrees C for 7 days, the specimens were subjected to shear testing using an MTS 858 Universal Testing Machine. Data were recorded and analyzed using a one-way ANOVA and t-test.

RESULTS

There was no significant difference in mean shear bond strength among the four groups (P = 0.575) or between the two groups with the highest and lowest mean shear bond strength (P = 0.288). The mean shear bond strength for all groups exceeded 21 MPa and 39 of 40 specimens exhibited cohesive fracture in porcelain.