Difference Between Plaque and Tartar

During your visit to the dentist, after he examines your mouth he may say that you have tartar build up, or that you have a dental plaque. The two, the plaque and tartar, are two different things. Dental plaque is a pale yellow layer of bacteria that forms on teeth naturally while tartar is a dental calculus. Tartar is a complication of plaque. These two conditions could be considered two stages of the same pathological process. However, there are a few basic differences between tartar and plaque.  This article will discuss how the dental plaque and tartar are formed, and the causes and the consequences of these formations on teeth in detail.


Plague can also be considered a biofilm because it consists of bacteria that attach themselves onto the surface of the teeth. Dentists consider plaque formation as a defence mechanism to prevent colonization of disease causing bacteria. Teeth do not have a natural mechanism to renew its surface as other body surfaces. Other body surfaces renew themselves by shedding surface cells and replacing them with new ones. This is one of the reasons for bacteria to attach and colonize easily on the surface of the teeth. Because the surface does not shed, bacteria may remain attached for a long time.

There are thousands of species of bacteria in dental plaques. Dental biofilm is the most diverse biofilm in the whole human body. Human oral cavity is home to over 25000 species of bacteria. This is because the environmental conditions may differ from tooth to tooth. Out of these 25000, about a 1000 are in the dental biofilm. These bacteria affect the condition around the teeth in a profound way. Bacteria in dental plaques damage the tooth enamel and cause dental caries. These bacteria digest sugars and secrete acids that react with the inorganic salts in the enamel of the teeth. The result is degradation of tooth enamel and dental caries. Due to local irritation and inflammation of gums, gingivitis and periodontitis can occur.


Tartar is the hard, yellow layer which forms around the base of your teeth if plaques are allowed to form freely and not removed promptly. The dental biofilm, also known as the dental plaque is soft enough to come off very easily at first. But, within 48 hours, it starts to harden and becomes a dental calculus in about 10 days. This dental calculus is called “tartar”. Hardening of the plaque is due to continuous accumulation of salts on the dental plaque. These salts may come from saliva and food. The surface of the calculus also serves as a surface for further plaque formation. The tooth surface is relatively smooth compared to the surface of a calculus. Therefore, the time taken for plaque build-up on healthy teeth is much longer than that for the plaque formation on a calculus. Therefore, with time, a thick hard dark yellow layer can form along the gum line, as well as below it.

Both plaque and calculus may cause inflammation of gums, but the extent of inflammation associated with a calculus is much greater than that with a plaque. Therefore, periodontal diseases are much more common with calculi than dental plaques.

What is the difference between Plaque and Tartar?

• Dental plaque is a biofilm made up of various oral cavity bacteria as a defence mechanism against pathogenic colonization. Tartar is a dental calculus, which is a consequence of plaque formation.

• Dental plaque is soft while calculus or the tartar is hard.

• Plaque can be removed with brushing while calculi cannot.

• Oral diseases are more common with tartar formation than with dental plaque formation.