Echos are very sensitive in picking up evidence for valves that leak. Seventy percent of normal people can be found to have trace tricuspid regurgitation. Forty percent of normal people have a little mitral regurgitation. If your mitral valve is structurally normal appearing, what you describe is very unlikely to ever cause you a problem. It may be reasonable to get another echo (ultrasound) image of your heart in a year or so, to make sure the situation is stable.
I'm not sure you need to see a cardiologist, and I would trust your primary care physician for his or her judgment regarding the need to see a cardiologist.
Chronic inflammation of the gums (gingivitis) can be associated with an increased risk of coronary artery disease. It is worthwhile working rigorously with your dentist to get this problem under control, for your teeth, and for your heart.