Are Healing Caps on dental implants necessary?

I had upper teeth 22,23,24 extracted and implants placed (with bone graft) in late November. In mid-December the stitches were removed, and in mid-January my dentist said everything looked good but he would like to add healing caps. Is this a necessary step? I plan on having the final step - crowns and abutments - done in Cancun in late March for 25% of cost. Can I skip the healing caps? What's the risk? Thanks, BC Canuck