Warfarin An anti coagulant drug of particular importance in dentistry due to its effects on bleeding and clotting. A dental patient taking warfarin who requires an invasive procedure such as an extraction, must have an INR taken prior to the procedure.

Whitening see bleaching.

Wisdom Teeth (Third molars) The last teeth to erupt at between 17 and 21 years old. There is one wisdom tooth at the very back of each quadrant. Some people do not have  wisdom teeth at all and some people have to have them extracted. This is often best done by an oral surgeon as impacted wisdom teeth can be difficult to remove. Once they have been removed the wisdom teeth can not grow back!