Etiology (Theories) of Dental Caries

Humoral Theory

Hippocrates and Galen were of the view that caries was due to humoral pathology and opined that a state of health or a specific disease was determined by the relative amount of humor, blood, phlegm, yellow bile and black bile

Galen

• He once stated that “when the head becomes diordered in nature, it produces many excrements from which lesions of lower organs occurs.”

• According to him, dental caries is produced by internal action of acid and corroding humors.

Worm Theory

The early history of India, Egypt, and Homer writings have also referred ‘worm’ as the cause of toothache. Therefore, it was hypothesized that caries could be recognized as a worm over tooth surface

Guy de Chauliac

• 1300 to 1368

• Was the first to report worms causing dental diseases

Van Leeuwenhoek

The father of microscopy, observed three different worms from the extracted teeth that act as demons and substituted foods as likely source

Dracunculus medinensis

A worm of drinking water was the tooth worm

Oil of Vitriol

The common treatment for worms at that time

Vital Theory

Earlier authors postulated that tooth decay originated from within the tooth itself like ‘gangrene"‘. They observed wider area beneath and smaller pin-point area on the top of the tooth histologically

Putrefaction Theory

A few authors suggested putrefaction as the cause of dental decay. But the availability of skeletal remains and the evidence that putrefaction did not advance the dental lesion quickly dispelled the idea

Parasitic Theory

The filamentous parasites in the membrane of tooth surfaces were considered as the causative agent for dental caries

Erdl

Described filamentous parasites in the membrane of tooth surfaces. He suggested that it was not the tooth worm but filamentous organisms on the tooth surface, which might have infiltrated into the tooth and produced dental caries

Sulfatase Theory

• Theory

• Bacterial toxins hydrlyze the ‘mucoitin sulfate’ of enamel and ‘chondroitin sulfate’ of dentin producing sulphuric acid that in turn causes decalcification of dental tissue

Inflammation Theory

• Theory

• Dental decay was because of internal inflammation

Chemical Theory

• Theory

• A few authors in early 19th century suggested that the teeth were destroyed by unidentified chemical agent formed in the oral cavity

Robertson

Proposed that the acid was formed by fermentation of food particles around teeth

Ficnus

Attributed dental caries to ‘denticolae’, the generic term for decay related microorganisms

Septic Theory

• Theory

• Hypothesized that acid capable of causing decalsification was actually produced by bacteria.

Acidogenic Theory

• Theory

• Is a blend of chemical and septic theories. According to this theory, caries is caused by acids produced by microorganisms of the oral cavity

Diet Detergent Theory

• Theory

• Hypotheiszed that the fibrous part of diet acts as detergent, which leads to physical removal of substrate required for initiation of caries

Proteolytic Theory

• Theory

• According to this theory, the proteolytic enzymes librated by oral bacteria destroy the organic matrix of enamel, resulting in loosening of apatite crystals with eventual loss of minerals