الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
 |  | from | 132 |  |  |
| | | from | 132 | | |
Abstract
This study aimed to evaluate the effect of acidic soft drinks on composite adhesion to enamel surface of human permanent molars by means of shear bond strength test and mode of failure distribution, and compare it to sound, uneroded teeth. A total of thirty-six sound permanent molars extracted for orthodontic purposes or periodontal problems were employed in this study.
Thirty-six human permanent molars were randomly divided into three equal groups. Each group consisted of twelve teeth. The buccal surface of all teeth were ground flat using 800 grit silicon carbide finishing paper and immersed in the corresponding erosive media (Coca-cola, Fanta and sprite) for 1 minute, 3 times a day for 1 day, after protecting half of each tooth with nail varnish. In between the erosive cycle teeth were stored in artificial saliva for a total of 24 hours. After demineralization-remineralization cycle, nail varnish was removed. The crown of each tooth was separated from the root 2mm below the cemento-enamel junction. The composite material was then applied to the buccal surface of each tooth using a plastic mold. All teeth were separated from the middle of the buccal surface in a buccolingual / palatal direction with a water-cooled, low-speed diamond disc that was replaced for every tooth in order to obtain two halves: experimental and control. Each specimen was then mounted in self curing acrylic resin with their restored buccal surface displayed perpendicular to the long axis of the block.
Specimens were mounted in Universal Testing Machine where shear bond strength was measured for each specimen by determining the force required to dislodge the composite from the enamel surface. Each specimen was then examined under a light stereomicroscope to determine the location and mode of failure.
Based on the results of this study, acidic soft drinks do affect the adhesion of composite to enamel in human permanent molars, as shear bond strength of composite in exposed specimens were significantly lower than that of protected specimens. Mode of failure of composite resin from eroded and uneroded surfaces was comparable.