الفهرس 
ACKNOWLEDGMENTOnly 14 pages are availabe for public view
 |  | from | 114 |  |  |
| | | from | 114 | | |
Abstract
The present study was carried out over a 9 months period. The study sample consisted of 17 patients who were in need of lingual arch space maintainers (group I) parallel to17 patients who were in need of two stainless steel crowns (group II) they were selected after fulfilling the inclusion criteria.
An informed consent were obtained from children’s parents or guardian after explanation of the purpose of the study to the parents (Appendix I), medical and dental history were taken. for group I lingual arch space maintainer was performed for each patient, while for group II only two stainless steel crowns were performed on the second primary molars. For ethical consideration, children having any dental condition requiring treatment were managed by using non metallic restorations.
The salivary concentrations of nickel and chromium were evaluated by a sample of saliva taken from each patient in both groups at four stages before the appliance or SSC cementation, after 1 month, after 3 months and after 6 months from the appliance or SSC cementation. The parents were instructed that the last meal should be at least 3 hours before the appointment of the four stages. The salivary sample was taken after rinsing the mouth with distilled water without stimulation, and then each sample had been taken a code number of each patient and was stored in ice box below 25C.
The samples were transferred to the central laboratory for microanalysis, Faculty of Science, Alexandria University.Preparation of the samples were accomplished using the conventional aqua regia digestion. The concentrations of nickel and chromium were determined (ppm) using a calibrated atomic absorption spectrophotometer.
The result of the present study shows a significant increase in the salivary levels of nickel and chromium elements in both groups after cementation of space maintainer appliances or SSC. The amount of released nickel and chromium were significantly higher in group I when compared to group II. The maximum increase of the concentration of nickel and chromium elements in both groups were seen after one month there after the concentration were gradually decreased till reach the baseline levels.
52
It can be concluded that the amount of salivary nickel and chromium released after lingual arch space maintainer appliances were more than those after SSC. Also the maximum amounts of released nickel and chromium were much lower than the dietary intake and were not capable of causing any toxicity.