الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 255 |  |  |
| | | from | 255 | | |
Abstract
The aim of this study was to compare the six generation bonding agents represented by AdheSE ?a twostep Selfetching adhesive? and Adper Prompt LPop ?A selfetch, singlestep ?allinone? bonding agent? with the fifth generation bonding agents represented by Excite. The comparison was directed to determine, the shear bond strength to human enamel and dentin, the degree of conversion of the adhesive resin, microleakage and antimicrobial activity of the bonding agents against cariogenic bacteria. For shear bond strength evaluation, one hundred caries free, unrestored human incisor teeth were selected for the study. They were mounted in a coldcured acrylic resin with the labial surface up. The labial surface was ground up to 600 grit silicon carbide abrasive paper until flat enamel or superfacial dentin area of at least 4 mm in diameter was exposed. The samples were stored in distilled water at 23 o C. The samples were loaded to fracture in a Universal Testing machine at a crosshead speed of 0.5 mm/min. Shear bond strength values were calculated for each group and subgroup. The results were analysed and compared using The percentages of degree of conversion for the three bonding agents used in the study were measured using the Fourier Transformation Infrared Spectroscopy. For the microleakage aspect of the study, class V were prepared on a total of twenty five recently extracted sound upper permanent human molar teeth with 90degree cavosurface margins and were located at 0.5mm below the cementoenamel Junction. TThe teeth were immersed in 2% methanol solution of Lishman dye for 24 hours. All teeth were sectioned in a mesiodistal direction using a diamond saw, and each section was then inspected under a stereomicroscope. The antimicrobial effects of the selfetch adhesives (AdheSE and Adper Prompt LPop) and the totaletch adhesive (Excite) were evaluated using the microorganisms streptococcus mutans, lactobacillus and actinomyces, with a disk diffusion method. Chlorhexidine 2% was used as a positive control. After incubation, zones of inhibited bacterial growth were observed and measured. Based on the results of this investigation the following conclusions of noteworthy can be made: 1. Generally, Adper Prompt LPop showed the lowest shear bond strength, the worst degree of conversion and the highest microleakage values. 2. The twostep selfetch adhesive AdheSE showed inhibitory zones against streptococcus mutans only, that was significantly inferior to the Chlorhexidine. 3. The singlestep selfetching adhesive (Adper Prompt LPop), exhibited antibacterial activity against streptococcus and actinomyces but fail to demonstrate antimicrobial action against lactobacillus. However the antibacterial action achieved were inferior to Chlorhexidine.