For the top menu, select Filters/Sampling/Poison-Disk Sampling.  In the pop-up menu, number of samples input a number that is close the umber of vertices.  If your scan is particularly noisy, reduce that number.  The higher the number, the longer it will take to process the filter.

When it's done, a new point cloud will be generated.  Click the layers button in the tool bar (it looks like stacked sheets).  On the right you will see the layers, and you can turn them on and off, and select which layer to work with.

Next click the newly created mesh, from the top menu select Filters/Remeshing-Reconstruction/Surfcase reconstruction: poisson.  In the pop-up  input 10-12 in the Octree depth, and 7-8 in the solver divide.  Click apply, and wait for the mesh.  It will generate a new mesh, which you can then clean up.

If you want, to, you can also skip the middle steps and go directly to the Surface reconstruction.

good luck

i have lot of hours of calibrating the 2 lasers of the scanner, and now i am almost satefied with the results.
now in to the next step meshlabb, that software is not my best i can.
i attachet a scrrenshot of the scanned mesh when i look at it in the browser.

will anyone help me out with some basics, i also atached a screehsot of it  when i import it to meshlab, how can i clean it up and get a smooth surface?