I think you are trying to ask a few different questions here.
1) If you have a specific issue with a heart valvue--mitral valve proplase with regurgitation, mitral regurgitation, etc, then there is a specific issue. When you clean the teeth the bacteria in your mouth will get into the bloodstream via the gums and for a few minutes you will have more than a normal level of bacteria in your blood. For the normal person this is not a problem. If you have a specific issue with a heart valve, the bacteria in the blood can sometimes get into the diseased valve, infect it, and then continue to spread infection. Since it is in the heart, it will continue to send bacteria in the blood all over the body. This is bad. This is why if you have a known heart issue, or in some cases a joint replacement, you take a dose of antibiotics before seeing the dentist. This would prevent or limit the bacteremia and limit the risk of dental procedures.

There is other preliminary research that having poor gum hygiene, infected teeth, or chronic tooth infections can be linked to higher rates of heart disease. I think the basic premise is that if you have infections in the gums then that would cause a more persistent higher level of bacteria in the blood--which would eventually do bad things to the heart. It makes sense on some level, but its not proven yet. Still, I would do your best to have healthy teeth and gums--you should do that anyway if you like to eat real food. Any heart benefit on top of it would certainly be a bonus!

David B. Feig