Causes Of Tooth Decay

Causes Of Tooth Decay

causes of tooth decay are bacteria in dental plaque - this is a mouth with decayed teethThe causes of tooth decay can be boiled down to one basic problem…

…bacterial infection inside the teeth and gums. So much of dentistry is really about preventing, diagnosing, removing and repairing the damage done by the bacterial flora that inhabit these spaces.  To understand how bacteria cause tooth decay, it’s important to first understand a bit more about dental plaque.

Dental plaque is a bacteria rich film that forms on the surface of your teeth.  It is the precursor to tarter, tooth decay, and gum disease.  Dental plaque is central to so many dental pathologies that we have a separate article devoted to that topic.  If you haven’t seen that article, it is probably best to read that first and then come back to this page.

In this article, we describe the actual processes by which the bacteria in dental plaque cause tooth decay and cavities.

Dental Plaque Causes Tooth Decay

When dental plaque first forms on the teeth, it is colonized mostly by aerobic bacteria.  This means the bacteria need oxygen to metabolize their food and energy.  But as the plaque grows and thickens, it becomes impossible for oxygen to permeate the film.  At this point, anaerobic bacteria, that do not need oxygen to live, will take over.

causes of tooth decay include anaerobic bacteria that produce lactic acid.  We also produce lactic acid when we exercise.You may have heard the term “anaerobic” before in reference to physical exercise.  When oxygen is not present in abundance – such as during a strenuous workout – our muscle tissues temporarily switch over to anaerobic metabolism.  This often causes soreness the next day.  The muscle soreness you feel is the result of lactic acid accumulation, a by-product of anaerobic metabolism.

The anaerobic bacteria that colonize dental plaque also produce lactic acid when they metabolize their food (our food), and this acid builds up in the areas surrounding your teeth.

Lactic Acid Causes Demineralization

The continuous deposition of lactic acid into the areas surrounding the tooth creates an increasingly acidic environment.  If the Ph gets below 5.5, the tooth will actually begin to leach out the calcium compounds that form its structure.  Basically, the tooth is dissolving – and that’s the bad news.

The good news is these same calcium compounds can actually be reabsorbed by the tooth.  The tooth can remineralize at an early stage in the decay process…but this doesn’t always happen.  causes of tooth decay include demineralization - this tooth is losing calcium and it has formed a dark spot where it has lost minerals.When a tooth loses calcium faster than it is being reabsorbed, a cavity will form.  A cavity is essentially a bacterial infection of the tooth that results in the deterioration of the mineralized tooth structures.