Mark,

You should call the dentist and say you are having either a cold or sinus problems and think it may be related to that tooth. It is his judgement call to treat you or not. If he says to come in, then ask him to look at the xray first and see if he thinks the sinus could be related to the tooth infection. This will bring more attention to both issues and he may prescribe antibiotics and see you next week or he may not. But yes, inform him first and then again if he does say come in.

Hope that helps........... keep us posted.