We had fleishik for dinner. Upon flossing in the morning, some meat was dislodged from between the teeth and it was swallowed. Does meat which remains in the mouth overnight lose its status in any way?
The meat does lose its status because of the enzymes in your mouth, therefore you do not have to wit 6 hours from swallowing the meat. However before eating milk you should do “kinuach vhadacha”, meaning, to rinse your mouth out with some liquid and eat some solid to wipe it out. This way you know your mouth is clear of any residue of the meat.
Ran Chulin 37b,Cochmas Adom 40-12, Aruch Hashulchan Y:D 89-5.