I just ran the ssd optimization feature of Defraggler and after restarting I didn't had the feeling that my drive is optimized in any way even the boot is taking about 2 - 3 secs longer.
Is there any way to undo this procedure?
I already tried a system restore point and it didn't work.
Sounds to me like your page files and indexes are being rebuilt, but no as far as I know there is no way (nor would it improve your situation if it did/does exist imho)
Optimization/Defragmentation are not top level (user interaction) OS changes and are not covered by System Restore or Windows, as a user understands the term, in general.
Edit: Did you happen to change Defraggler's settings to move large files to the end of the Drive?
As far as I can tell SSD optimisation is a write process, so nothing can undo it.
Defraggler's SSD optimisation is reportedly a zero fill process, i.e the SSD is filled with zero-byte pages which are then deleted. If you have a TRIM enabled device all the zero filled pages will be flagged as invalid, and made available to the garbage collector. The GC will empty these pages and compact them into blocks, as a background task. They will then be available for future writes. The empty state of an SSD page is all ones, despite the fact that a read will display as zeroes.(The SSD controller won't let you access an empty page directly.)
It may be that, depending on the size of the SSD and the ratio of used/free space, and how long your pc has been powered up, that the GC hasn't had time to complete its processing. Just leave the pc powered on for a few hours.
If you have TRIM enabled then SSD optimisation should very rarely be needed, maybe once or twice a year if you must. If you don't have TRIM then your SSD and O/S must be quite old. Zero filling will hammer the SSD and the MFT pages in particular.
I don't know about Windows SSD optimisation under Win 8 (and 7?). Well, I know it sends a TRIM command to all unused pages, but I don't think it is as clunky as zero filling. Zero filling is a way of 'trimming' SSD's where TRIM is not enabled, perhaps that's why Piriform use it. But, non-TRIM is heading towards obsolescence quite quickly.