Here is an easy home remedy, which might give you the desired results. Rub a small amount of toothpaste on the scratch and polish the CD with a soft cloth and any petroleum-based polishing solution (like clear shoe polish). Squirt a drop of Brasso and wipe it with a clean cloth.
Technology to the rescue :
There are many softwares available on the net, which enable the recovery of the CD data. BadCopy Pro is one such software, which can be used to recover destroyed data and files from a range of media.
Just a few clicks is all it requires to recover the disc from almost all kind of damage situation; be it corrupted, lost data, unreadable or defective.
DiskDoctors is another popular company, which offers both software and solutions to recover data from a scratched CDs and DVDs.