There are already medical reports that throat cancer is associated with oral sex. That is why you should take good care of your oral cavity and throat.
Brush your teeth at least twice a day with an anti-bacterial toothpaste. Use a soft type toothbrush bristle to avoid microscopic scrapes or bleeding gums.
Gargle with a mouthwash. This will sanitize not only your mouth but throat as well. If you can not afford mouthwash, some suggest a simple luke warm water mixed with salt. In fact dentists recommend water and salt solution to clean an open wound after a tooth extraction.
But best of all, use condoms even during oral sex. Oral sex using a condom might not be that satisfying but it is better safe than sorry.