hepatitis B virus (HBV) is more communicable then HIV regarding needle sticks. For instance you have a 30% chance of acquiring HBV from an infected needle stick, where-as HIV has a 0.5 - 1% chance of acquiring. Now teh risk to a patient is only if you stick your self and then stick them with the same needle. In that case, you need to start worrying about law suits. HBV is a blood born virus and usually only transmissible through blood contact. Since yoru not going to have sex with your patients while there under nitrous and your not going to stick them with an infected needle, there is no reason they shouldnt let you in.