Can I be allergic to my synthetic bone graft?

It is highly unlikely.  My suggestion is to wait and see what happens to the symptoms since this is a recent extraction. If the symptoms continue and everything is ruled out its best to do a blood draw and send it to Clifford Laboratories in Springfield Colorado to rule out any reaction to the material that was used.

As previously mentioned, an allergy to any bone graft material whether human, bovine or synthetic is essentially nonexistent. This is because of the processing they go through. All allergenic material is removed. If it were an allergy to this or the membrane (which is also non allergenic) there would be swelling and pain at the graft site. You are describing something similar to a contact dermatitis. This is most likely from latex gloves or possibly from topical anesthesia used. Speak to your doctor to find out what may have been used to prevent this again. A low dose steroid pack should help if there is no resolution 

Regardless of the type of graft material that was used (freeze dried, bovine, artificial), they are all sterile and generally non-allergenic.  Theoretically, an individual can be allergic to anything that is considered a foreign body.  However, it would be very unlikely that you would have a reaction to the bone graft material or membrane (if one was used) as these are made from materials that naturally occur in the body.  The more probable explanation is a reaction to latex gloves or something else that contacted your lips/face (powder, ointment, surgical drapes or ice packs).  If it is improving, it will continue to do so and no treatment is needed.  If it remains the same or gets worse, you should see your dentist and he/she may recommend topical steroids.