My FS told me to floss every single day - so yes, it is important. Apparently some oral bacteria spreads really easily in the system and lowers chances of conception. I recently read an article about men and the impact poor dental hygiene can have on fertility, can't find the link now... but that scares me as DP hasn't been to the dentist for nearly 20 years and refuses to go ! ! However, FS wasn't concerned about DP flossing, only me...