الفهرس 
Review of literatureOnly 14 pages are availabe for public view
 |  | from | 76 |  |  |
| | | from | 76 | | |
Abstract
Despite extensive research on various preventive technologies over years, dental caries remains a common undesirable clinical problem. Several mechanisms have been suggested to reduce the incidence of dental caries, including the improvement of oral health-related behaviors, changing dietary habits altogether with topical application of fluoride.
Professional sources of fluoride such as varnishes and fluoride releasing sealants have become viable treatment alternatives. One of the most common preventive ways; is the use of synthetic antimicrobials. Increasing interest towards natural alternatives to overcome the devastating side effects of synthetic antimicrobials is prevalent.
The aim of the current study was to compare the in vitro effects of propolis and propolis fluoride containing dental varnishes regarding their antibacterial effect against S.mutans and fluoride ion release.
The study was divided into 2 parts; the first was a quantitative analysis of S.mutans sensitivity to propolis, propolis fluoride and NaF containing varnishes using disk diffusion test. While the second part was a fluoride ion release test to evaluate the fluoride ion release into artificial saliva after one hour and twenty four hours of application of propolis, propolis fluoride and NaF varnishes.
In the disc diffusion test, sterile filter paper discs impregnated with 10ul of propolis varnish, propolis fluoride varnish or sodium fluoride varnish were used. Disks impregnated with 2% CHX solution were used as controls .The disks were placed inside petri-dishes containing brain heart infusion agar cultured with an isolated strain of S.mutans. The petri-dishes were then incubated at 37oC for 24 hours as follows:
Ia: propolis varnish(P).
IIa: propolis-fluoride varnish(PF).
IIIa: 5% sodium fluoride varnish(F).
IVa: 2% Chlorhexidine gluconate as a positive control(CHX).
Subsequently the plates were assessed for uniform growth of S.mutans and inhibition zones around the discs that were measured in millimiters.
For the fluoride ion release test, a total of 45 enamel specimens which were prepared from the buccal and lingual surfaces of freshly extracted primary molars that were randomly divided among 3 groups as follows;
Ib: propolis varnish(P) , (n=15).
IIb: propolis-fluoride varnish(PF) , (n=15).
IIIb: 5% sodium fluoride varnish(F) , (n=15).
Enamel surfaces were covered with an acid resistant varnish except for 3x3 mm windows that were covered with dental varnishes. Each specimen was placed in a test tube containing 10 ml artificial saliva. Fluoride ion concentration was assessed by ion selective electrode at 1 hour and 24 hours from the time of varnish application. At the time of assessment, each specimen was removed, rinsed with deionized water and placed in a new test tube containing fresh 10 ml of artificial saliva.
Results showed that the highest mean ± SD values of bacterial sensitivity were recorded for 2% CHX group followed by NaF group then PF group.
Meanwhile, the lowest mean ± SD value were recorded with P group. There was no significant difference between CHX, NaF and PF groups, while P group showed the least bacterial inhibitory effect. This means that propolis has a bacterial inhibitory effect but as it is concentration dependent, further studies could be carried out using propolis with different concentrations.
As for the fluoride ion release, the highest mean ± SD values of fluoride ion release were recorded for NaF group followed by PF group. Meanwhile the lowest mean ± SD value were recorded with P group. There was statistically significant difference among NaF, PF and P groups after 1 hour and 24 hour from varnish application. The reason behind propolis having the lowest mean ± SD value may be attributed to the resinous nature of propolis that hindered the fluoride ion release.