Are Dental Caries Reversible?

Manjusha Madkaiker


Dental caries is a multifactorial irreversible microbial disease of the calcified tissues of the teeth, which is characterized by demineralization of the inorganic portion and destruction of the organic substance of the tooth, which often leads to cavitation. Dental caries is one of mankind’s ancient and longest disease associated with the oral profession. Everyday around 2.3 billion people are affected by dental caries.

But since the late 20th century with new advancement in technologies there is slow but gradual progress in the development of the vaccine .1972, a caries vaccine was said to be in animal testing in England.


1. Acidogenic theory – this theory was proposed by WD Miller in the year 1881 which states the combined effect of acid and oral microbes leads to the decalcification of tooth structure .This theory was incidentally evolved, and according to this theory the microbes in the oral cavity metabolize the dietary starch and lead to production of organic acids that hence dissolves the tooth structure .

2.Proteolytic Theory – Proposed by Pincus in the year 1949 which states that the proteolytic breakdown of dental cuticle is the first step in the various process. He proposed that Nasmyth’s membrane and enamel proteins are mucoprotein which are acted upon by the sulphates enzyme of the bacilli and yield sulphuric acid, this acid combines with the calcium of hydroxyapatite crystals and thus destroy the inorganic components of the enamel.

3.Protelysis-Chelation theory – Proposed by Schatz in the year 1955. Chelation is the process which leads to the formation of covalent bonds which leads to poorly dissociated and/or weakly ionised compound .Therefore dental caries are considered as the bacterial destruction of organic components of enamel and the breakdown products of these organic components to have chelating properties and thus dissolving the minerals in the enamel even at the neutral/alkaline pH.


1. Nonspecific plaque hypothesis

In the end of 19th century the cause of dental infection was said to be due to non-specific overgrowth of all bacteria in dental plaque this was called as the nonspecific plaque hypothesis given by Black in 1884 and Miller 1890. This hypothesis was proposed irrespective of the virulence of the bacteria.

So, the best way of disease prevention in the 19th century was non-specific mechanical removal of as much plaque as possible by e.g., tooth brushing or tooth picking.

The new advancements in the 20th century lead to to isolate and identify bacteria led which resulted in the abandoning of the NSPH. But mechanical plaque removal remained the most efficient way of preventing disease.

2.Specific plaque hypothesis

This hypothesis proposed by that the use of antibiotics against specific bacterial species could cure and prevent caries. However, results even today, are not very promising, the antibiotics reduced the abundance of cariogenic bacteria but failed to eliminate them thus as soon as the treatment was stopped, abundance increased while a long period of treatment leads to antibiotic resistance.

3.Ecological plaque hypothesis

4.Keystone pathogen hypothesis.


1. On top i.e. the floating iceberg represents the clinical cases.

2. The submerged portion represents the carriers.

3. The part in the waterline represents the apparent and unapparent cases.

4. And at the tip are the ones with multiple health problems.


Vaccines are an immunobiological substance designed to produce specific protection against a given disease. It stimulates the production of a protective antibody and other immune mechanisms. Vaccines are prepared from live, inactivated or killed organisms, and toxoids.

Immune response is divided Into

1. Primary response

2. Secondary response (booster response)

Although development of a vaccine for started around 30 years back, but no success was achieved due various reasons.

But the formation of dental caries can be prevented or the progression can be slowed by the use of fluoride, use of sugarless products and sealants, and increased access to dental care have had a significant impact on the amount of disease in people. Many of these approaches can be broadly effective. Hence the dental caries can be reversible to a certain extend. However, economic, behavioural, or cultural barriers have continued the epidemic of dental disease.

Integrating the caries vaccine after its development into public health programs could be beneficial in bring dental caries to a minimal level.