الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
Remineralizing agents were produced for a conservative approach. CAD is an inner layer of dental caries has low mechanical properties and acceptable to repair or remineralization. This study was conducted to explore the effect of two application protocols of two remineralizing agents on the shear bond strength of resin composite to artificially caries-affected dentin as well as micro hardness. For bond strength test, a total of 72 anterior bovine teeth were extracted from sacrificed bovine jaws. The labial surface of the cervical half was ground flat to remove the enamel and expose an area of nearly 5×5mm diameter of dentin. The teeth with artificial caries-affected dentin (CAD) were divided into two main groups 24 samples each according to the remineralizing agent (Remin Pro and MI paste plus). Each main group is divided into two subgroups, 12 samples each according to the time of application of remineralizing agents (7 days and 14 days). In addition, there are two control groups 12 samples each (positive control: sound dentin) and negative control: CAD. For microhardness test, a total 30 of anterior bovine teeth were prepared and distributed in the groups and subgroups, five samples in each as previously mentioned. 10% of citric acid, PH=4.5 was used as demineralizing agent. Each Specimen was separately immersed in the 10 ml of demineralizing solution for 5 minutes in glass bottle per day for one week to stimulate caries like lesion. After that, it was rinsed and stored in the deionized water till it was subjected to remineralization. 0.5 gm of remineralizing agents was applied to the caries affected flat dentin surface for 30 minutes in a passive way per day for two periods of time (7days, 14 days) and then rinsed and stored in deionized water,
The results of shear bond strength testing showed that positive control and MI paste 7 days had higher statistically significant shear bond strength values compared to the other groups without statistically significant difference between them. While MI paste 14 days, Remin Pro 14 days and Remin Pro 7days showed higher statistically significant shear bond strength than the negative control without a statistical significant difference among them. The results of the micro hardness test showed that, MI paste (7 days) had the highest statistically significant micro hardness value among all groups. Remin Pro (7 days) and positive control had a higher statistically significant micro hardness than MI paste plus and Remin Pro (14 days) without statistical significant difference between them. Both MI paste plus and Remin Pro (14 days) showed the lower statistically significant micro hardness than other groups without statistical significant difference between them. There was not a statistically significant difference between the negative control and MI paste plus (14days).
Under the limitations of this study, the following conclusions could be suggested:
1- The demineralization process by acid application had a negative influence on both shear bond strength of CAD to resin composite and microhardness of CAD.
2- Remineralization for 7 days for caries affected dentin by both ReminPro and MI paste Plus, were effective in improving the shear bond strength of resin composite to CAD and microhardness.
3- Using the deionized water as a storage media had a detrimental effect on both microhardness and shear bond strength of CAD when the period of storage of CAD exceeded to 14 days.
Recommendations:
1-Further study is recommended to evaluate the effect of storage media on the CAD mechanical properties during remineralization.
2-It is recommended to evaluate the effect of two types of adhesive, mid and ultramild on the bond strength of remineralized CAD.