الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 130 |  |  |
| | | from | 130 | | |
Abstract
This is in vitro study was carried out to investigate the antibacterial efficacy, fluoride release and recharge ability of new bioactive restorative materials. Three types of bioactive restorative materials were used; Bioactive composite (ACTIVA BioACTIVE restorative) , Resin modified glass- ionomer (FUJI II LC) and Conventional glass- ionomer (Fuji IX GP FAST)
One hundred and twenty discs were prepared. Ninety discs for antibacterial test and thirty for fluoride release and recharge ability. The ninety discs were divided into 3 groups according to the type of tested material; bioactive composite (ACTIVA) (A1), resin modified glass-ionomer ( Fuji II LC) (A2) and conventional glass- ionomer (Fuji iX GP) (A3).
Each group were divided into two equal subgroup of 15 disc each (B) according to type of bacteria to be used; Streptococcus mutans (B1) and Lactobacillus acidophilus (B2). Discs in each subgroup were tested for antibacterial activity (C) at different testing periods of (C1) 1 day, (C2) 1 week, (C3) 2 weeks and (C4) 3 weeks.
Each specimen was prepared by injection each mix into a split Teflon ring with a central hole having dimensions (10mm in diameter X 2mm in thickness). The split Teflon mold was encircled with a copper ring. Each mold was placed on the top of a microscope glass slide and a Mylar strip then filled with the each tested material and second Mylar strip was used to cover the top side of the mold and another microscope glass slide was applied over it .load was applied to insure no air was trapped. Specimens were carefully removed from molds.
The antibacterial efficacy was evaluated by using the agar diffusion test; the bacteria were cultivated in specific culture mediums; Trypticase- soy broth agar for S.M and Lactobacillus MRS Broth agar for L.A. Petri dishes 15cm in diameter containing 30 ml agar to a thickness of 2 mm were seeded by 1ml of microbial suspension of each bacteria.
Nine discs from each tested materials formulation were inserted into previously prepared wells in the agar medium in each Petri dish. Monitoring of the antibacterial effect was done at day1, 1 week, 2 weeks and 3 weeks. where a new dishes and fresh agar with microorganisms were prepared every 7 days.
The antibacterial effect was estimated by measuring of the total inhibition zone (disc + inhibition zone around it) in millimeters by Digital caliper at three different points, and then the mean was recorded for each inhibition zone.
The fluoride release was carried out by immersion of 10 discs of each tested materials (A1, A2, A3) in 10 individually numbered tubes, each tube contains 1 ml of deionized water. The tubes were placed in the incubator at 370c. In our study the fluoride release of each tested materials was done by 2 ml of Fluoride reagent was added to each sample’s solution of each disc. The fluoride release measurement was carried out by using Multiparameter bench photometer (HI 83200, Woonsocket, USA) after day 1, 1 week, 1 month, 2 months and 3 months.
Refluoridation of each tested disc was carried as follow. On day 90 after measurement of fluoride release, the discs were cleansed by rinsing them three times with 5ml deionized water, dried for 5 min by filter paper. Then immersed in 0.2% NaF solution for 5 min to stimulate the fluoride ion recharge. The discs were rinsed with 5 ml deionized water and then each disc was placed in a glass tube containing 1 ml deionized water and stored in an incubator at 37°C. The previous procedures of fluoride release were repeated again. The fluoride release measurements were determined after 1 day, 1 week, 2 weeks and 1 month. The concentration of fluoride in each sample solution was measured using Multiparameter bench photometer.
The analysis of variance ANOVA test revealed that:
1- There was a statistical significant difference p<0.001 in the mean value between the inhibition zone of S. mutans of the three tested materials Fuji IXGP, Fuji II LC and ACTIVA groups. At different testing periods (day1, 1 week and 2 weeks).
2- There was no statistical significant difference p=0.473 between the inhibition zone of the three tested materials Fuji IX GP, Fuji II LC and ACTIVA groups at 3 weeks.
3- There was a statistical significant difference p<0.001 between the inhibition zone of Lactobacillus of the three tested materials Fuji IXGP, Fuji II LC and ACTIVA groups at different testing periods (day1 and 1 week).
4- There was no statistical significant difference p=0.473 between the inhibition zone of the three tested materials at (2 weeks and 3 weeks).
5- A statistically significant difference in the fluoride release between the three tested materials at different testing periods.
6-There was a statistical significant difference in the recharge ability of the three tested materials along the testing period of the study (day1, 1 week, 2 weeks, 3 weeks and 4 weeks).
7- There was no statistical significant difference p=0.473 between, Fuji II LC and ACTIVA groups at (2weeks, 3 weeks and 4weeks).
Under the limit of the present study, it could be concluded that:
1. All tested restoratives presented a certain degree of antibacterial inhibitory action that is related to the material type, where the addition of methacrylate to glass ionomer negatively affects its antibacterial action.
2. The antibacterial efficacy of all tested materials start to emerge as early as 24 hours and continue after that.
3. Fluoride release and recharge by the tested restoratives is both time and materials dependent.
4. The antibacterial inhibitory action, fluoride release and recharge of conventional glass ionomer start higher and continue performing better overtime than other tested restoratives.