How long can I keep the temporary crown?


After I got my implant, a temporary crown was place right after (last oct 25, 2012), until now (march 2013) I’m still wearing a temporary crown . Will it compromise my implant since I didn’t put the permanent crown on right away? How long can I hold on to with my temporary crown. What is the general cost for one permanent crown (I’m in San Francisco, CA)? Thank you