As long as you change the oil as recommended (every 3000 miles, I think), you will not have any problem using detergent oil with a newly rebuilt engine or with an engine that has had the oil pan removed and thoroughly cleaned.
It might be harmful if you change from non-detergent oil to a detergent oil if there are accumulated deposits in the oil pan. These might get back into suspension and cause clogging and maybe extra wear?
