Yes, there certainly are. You should consult hematology and find out the patient's platelet levels. If you haven't done so, there are two major dental procedures you need to avoid until you have consulted hem: extractions, and IAN blocks. Obviously you need to be cautious w/ extractions due to the inability to clot. As far as mand blocks, should you pierce any vessels on your way towards the IAN, if the patient has lowe platelets they may not clot properly. That blood can pool in the sublingual space, and eventually get to the point where it restricts the airway.
Patients w/ thrombocytopenia many times will get ddAVP, which is intranasal desmopressin. This can increase plasma levels of von willebrand factor and also factor VIII. This is done prior to the ext to compensate for any inability to clot. More importantly, it covers your ass should any complications arise.
As I stated in the beginning of my response, the main thing you need to do is consult their hematologist and follow their recommendations. They may take some platelet studies and will likely admin ddAVP prior to blocks and extractions.
That, or you can be like a certain oral surgery program near us, who decided they knew more than the hemonc consult that was provided and went ahead with the extractions on the patient without the ddavp. They then decided to call us and whine when the patient wouldn't clot even though we had spent 20 mins doing the legwork for them which they simply chose to ignore