@Karasahin: Yes, basically its more towards the Data Migration side rather than taking a backup and restoring it. The Data you upload to both environments should typically be the same and then you can build same cases around it.
Back-up and restore capability is only in the hands of Microsoft and Point-in-time backups maybe requested for the Production environment. I don't think Microsoft will cater the request of copying from Prod to Sandbox or vice versa at the current moment in time.