Serious health problems, such as heart disease, diabetes and stroke, have been linked to poor oral health, including tooth decay and gum disease. Serious health problems can occur if symptoms like cavities and abscesses go untreated. In rare instances, death may occur if treatment is not received in a timely fashion. Tooth decay is a contagious bacterial infection that can sometimes lead to life-threatening infections in the body. For example, pregnant women who have periodontal disease may be more likely to have a baby that is born too early and too small.