الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 108 |  |  |
| | | from | 108 | | |
Abstract
This research aimed to investigate the effect of topical fluoridation on the surface roughness of enamel and its shear bond strength to various formulations of glass ionomer restoratives. 90 freshly extracted human deciduous incisors were used to construct the specimens. Two techniques of fluoridation were utilized which were the passive application using a stannous fluoride gel which remained for two minutes on the enamel surface while in the other technique fluoridation was enhanced electrically using a specially constructed apparatus. The application was repeated twice on each specimen. All labial enamel surfaces of the 90 specimens were assessed for surface roughness using a surface roughness tester (TR100 Surface Roughness Tester, Time group Inc., USA). The control non fluoridated specimens comprised 30 specimens, the passively fluoridated , 30 specimens and the remaining 30 specimens belonged to the electric fluoridation group.
The control non fluoridated and the fluoridated enamel surfaces were bonded to different glass ionomer formulations, where in the first group of 30 specimens the enamel surfaces were bonded to a pure glass ionomer (Ketac Fil, Espe) comprising 10 control, 10 passively fluoridated and 10 electrically fluoridated specimens. In the second group (30 specimens) , the enamel surfaces were bonded to a light polymeised resin modified glass ionomer restorative (Photac Fil, Espe) while in the third group (30 specimens), the enamel surfaces were bonded to a light polymerized poly-acid modified composite compomer restorative ( F 2000, Espe). The shear bond strength between the enamel surfaces and various restoratives was determined using a universal testing machine ( Lloyd, LR 5K, England ).
Results of surface roughness measurements and shear bond strength were tabulated and statistically analyzed. The results indicated that both fluoridation techniques increased the surface roughness of enamel particularly electric fluoridation where a significant difference was detected between the non fluoridated control and both fluoridated experimental groups. The assessment of shear bond strength revealed a significant effect for the material formulation. Moreover, fluoridation enhanced the bond strength of both the resin containing formulations Photac Fil and F2000 but did not have the same effect in case of pure glass ionomer Ketac Fil.
With respect to the research design and the materials under investigation, the following conclusions could be detected.
1. Fluoridation enhances the surface roughness of enamel.
2. Electric fluoridation possesses a significant effect on roughening the enamel surface compared to passive fluoridation.
3. Shear bond strength of glass ionomer to enamel is material dependent rather than fluoridation dependent.
4. Fluoridation improves the shear bond strength of resin containing glass ionomer formulations to enamel.
Clinical recommendation
It is advisable to utilize a compomer restorative after fluoridation of enamel to optimize the resultant bond strength.