Healthy teeth look straight and white and are seated properly in healthy gums. When teeth look unhealthy, it is typically due to yellowed enamel on the teeth's surface or to problems with the gums, including swelling, gaps around the teeth, bleeding or a gum color that is too pale or bright red.
Good-Gums points out that healthy gums are pink rather than bright red or pale. They are firm and adhere tightly to the teeth; when gums are swollen or are separated from the teeth, the teeth themselves appear unhealthy.
Tooth color is also key to the appearance of healthy teeth. Although teeth that are yellow are not necessarily unhealthy, studies show that they can make a person appear up to five years older. Yellowed teeth can be caused by dental problems involving the tooth's enamel or dentin, but the cause is more often extrinsic, coming from food and drink choices, smoking or use of certain antibiotics. Avoiding coffee, cola, tea and red wine helps prevent yellowing teeth.
Good gum care is key to keeping teeth healthy and maintaining their appearance. Flossing after each meal removes plaque, which can develop into tartar, harming the teeth and gums. The use of antibacterial mouth rinses also helps to fight plaque and tartar and to protect teeth from decay.