Google is a good friend of yours, you can always find a solution. If you just try to search for, "scan images c#" google would return the best threads that have the solution to your problem.
I did the same, and a CodeProject solution, posted in the comments, was achieved.
Scan and Save Images to a Database in C# Using Dynamic .NET TWAIN[
^]. You can use any API that suits you, you don't need to worry about them. However, check for the rating of that API and its capabilities.