Hi Becky:  Wow this is a tough question.  You have 3 different Drs giving you 3 different recommendations?  This is always really hard to figure out, especially since you would hope that at least 2 of the recommendations would be similar.

Do any of the 3 opinions coincide with how you feel about it?  Aside from getting a 4th opinion, to give you the most best answer, you could read the ADA's recommendations for clinician guidelines on patients recieving oral bisphosphonates preparing for extration or implantation.  Here's the link from the ADA (American Dental Association) on this topic.  Read through this and see if it helps any.  If it doesn't answer your question, you could consult with another oral surgeon and see what they advise.

After reading the above link, the conclusion is that this problem is a low risk, but precautions should still be taken if you have additional problems like periodontitis, infection, or corticosteriod use etc.

If the link doesn't help, then I would call either another oral surgeon or a bone specialist and ask if there is a certain amount of time that you should be off of the medication prior to the procedure.

Good luck with this.