TB20 pilot experiences loss of oil pressure indication during climb and elects to return to departure airport for an uneventful landing. Oil pressure indication returns during the descent.

Narrative

Departed on IFR flight plan and during climb to 11;000 cruising altitude; engine oil pressure indicator fell to zero. Engine was running normally. I informed ATC; that I had the indicator showing no oil pressure; and that the engine was running; and I was not sure if it was just an instrumentation error. They offered any assistance I wanted. I decided to return to my departure airport as a precaution. I did not declare an emergency. I proceeded direct to the airport and was given priority status. The Tower was handling the situation as an emergency. The oil pressure indicator returned to a normal status on my descent; the engine never seemed to run abnormally. Landing was normal.Post landing I taxied in front of the Tower; a restricted zone; 2 men were standing there; I thought that is where they wanted me; and the Tower instructed me to taxi north or south; which I did. After shutdown at the FBO; fire truck with a friendly man wearing a hazard suit asked if we were OK; I said yes and explained what happened. I think everyone was relieved nothing happened.It is difficult to troubleshoot a potential catastrophic event for the engine in flight. I feel the precautionary landing the safest option for me and my passengers. My airplane also has an oil pressure annunciator light; which did not illuminate during this event; however; if faulty wiring was a problem; its lack of operation is not helpful.