This study investigated the influence of bioactive materials on the dentin surface whitened. Material and Methods: Three bovine teeth were shaped into three dentin wafers. Each wafer was then sectioned, into six dentin slices. One slice from each tooth was distributed into one of 6 groups: 1.CG = control group (distilled water); 2.WT = whitening treatment; 3.WT + MI Paste Plus, applied once a day; 4.WT + Relief ACP30, applied once a day for 30 mintes; 5.WT + Relief ACP60, applied once a day for 60 minutes; 6.WT + Biosilicate ® , applied once a week. All groups were treated over 14 days. Results: CG presented all dentinal tubules occluded by smear layer; WT group was observed all dentinal tubules opened. In the groups 3, 4 and 6, tubules were occluded. Group 5, dentinal tubules were completely occluded by mineral deposits. Conclusion: The use of bioactive materials immediately after whitening treatment can reduce or even avoid the demineralization effect of whitening and avoid exposing dentinal tubules.

No abstract

No abstract

No abstract

In recent years WiMAX has been presented by its promoters as a complete solution for the broadband access market. Since it is a wireless technology, it can easily serve the most remote and difficult areas. Even more important, the mobile version of WiMAX added the potential of sustainable growth and later adaptation of all its services to compete at the fixed and mobile markets.This paper attempts to analyze the relevance of WIMAX for emerging markets where the demand for broadband services is growing at a very fast pace, and wireline infrastructures either do not exist or are not in an appropriate state of conservation. To support the study, a techno-economic analysis was performed for the region of Luanda, Angola, taking into consideration geographic and demographic conditions, different service packages, tariffs, roll-out strategies, and sensitivity to adoption rates. The results show that WiMAX can be a feasible and profitable solution specially suited for emerging markets.