No, it is not the same.
A domain must be delegated to some name servers. For example, example.com is currently delegated to a.iana-servers.net (among others), which means that the .com top-level name servers know that a.iana-servers.net will know the IP address.
# Linux command to find out the name servers
host -t ns example.com
Registering a domain means that you have the right to control it. Typically you would register a domain and make a deal with a service provider about using their name servers, and either you or the service provider would then inform the .com servers about your nameservers. Of course, you could do this all by yourself, if you own a couple of DNS servers.
Even if you managed to inject your DNS record to a Google name server, nobody would really know to ask for it, because the .com servers wouldn't know it's there. While this might work for a while for the users who use Google name servers as their primary DNS servers, I'm positive Google would soon delete your illegal DNS record.
Further reading: Wikipedia: Domain Name System