Hello there, thank you for your excellent question! There has been intense and ongoing discussion about the effects of bisphosphonate medication on the possibility of osteonecrosis of the jaw. However, I haven't seen a specific blood level used to determine whether one should go forward with oral surgery or not. I would recommend informing both your oral surgeon about your Fosamax use and your osteoporosis specialist about your upcoming surgery. The latest research indicates that oral bisphosphonates like Fosamax do not appear to have a negative impact on the jaw. However, some doctors recommend holding off a bisphosphonate use for a few months before and ofter the surgery (but talk to your doctor before going on or off any prescription medication). For more information, see http://www.healthcentral.com/osteoporosis/c/9487/8868/break-oral/