Physical Dependence Question

If one just finished going through physical withdrawals from an OC habit and then immediately after took percs for back pain (I have chronic back pain with 6 herniated discs), how long do you think it would take to build a physical dependence again?  I took 7 10/325 percs that were prescribed to me and then 20 or so hours later I felt mostly fine, but a little off balance.  I want to make sure that I can set a regimine up where I can take the percs when needed to manage my pain, but only enough so I don't develop a bad physical dependence considering I just finished a detox.

[suboxisBAD]

And just to clarify, I took the first 10/325 perc two days after the physical withdrawal symptoms ended and then 6 more over a 2 day period.  I then stopped for about 20 hours with no physical withdrawal symptoms.  I only plan on taking as needed for pain and no more than one every four hours, but want to avoid physical dependence for good.