Dental Caries: Theories, Microbes, and the Chemistry of Decay

Dental Caries: Theories, Microbes, and the Chemistry of Decay

Question. Describe the theories of etiology of dental caries.
Or
Defy dental caries and theories associated with dental caries.
Or
Describe the theories of dental caries.

Answer. “Dental caries is an irreversible progressive microbial disease of the calcified tissues of the teeth, characterized by the demineralization of the inorganic portion and distortion of the organic substances of the tooth, which often leads to cavitation”.

“Understanding the role of theories in explaining dental caries: Q&A explained”

• Etiology of dental caries is a very complex process, which is often explained with the help of some theories.
  • Acidogenic theory
  • Proteolytic theory
  • Proteolytic chelation theory
  • Sucrose chelation theory
  • Autoimmune theory.

“Importance of studying theories, microbes, and decay chemistry for better outcomes: Questions explained”

Acidogenic Theory

• This theory is also known as Miller’s chemicoparasitic theory.
• It proposes that acid formed due to the fermentation of dietary carbohydrates by oral bacteria leads to progressive decalcification of the tooth. Structures with subsequent degeneration of the organic matrix.
• Acidogenic theory states that the process of dental caries involves two stages.
  1. Initial stage: Production of organic acid occurs as a result of fthe fermentation ofcarbohydrates by the Plaque bacteria.
  2. Later stage: Acid causes decalcification of enamel followed by dentin and thereby causes total destruction of these two along with dissolution of their softened residues.
  The final result is cavity formation.
• According to Miller there are four important factors,which can influence the process of tooth destruction in dental caries.
  1. Dietary carbohydrates
  2. Microorganisms
  3. Acids
  4. Dental plaque.

“Common challenges in understanding dental caries theories effectively: FAQs provided”

Role of Carbohydrates

• Fermentable dietary carbohydrates play an important role in the causation of caries, e.g.,, glucose, fructo,se and sucrose.
• Among t,hem sucrose is more potent.
• These sugars are easily and rapidly fermented by cariogenic bacteria in the oral cavity to produce acid at or near the tooth surface and cause dissolution of the hydroxyapatite crystal of the enamel, followed by the dentin.The riskk of caries incidence increases greatly if the dietary sugar is sticky which remains adhered to the tooth surface for a long time after taking the meal.
• Following the ingestion of these sugars the pH of the Plaque falls to 4.5 to 5 within 1 to 3 minutes and neutralization occurs after 10 to 30 minutes.
• Glucose, sucrose, and fructose, etc., are rapidlydiffusedd into the plaque due to their low molecular weight.

“Steps to explain theories of dental caries: Acidogenic vs proteolytic theory: Q&A guide”

Role of Microorganisms

• A large number of microorganisms play individual role in dental caries production and among them the most important one is Streptococcus mutans.
  • It readily ferments the dietary carbohydrate to produce acid, which causes tooth destruction.
  • It synthesizes dextran from sucrose, which helps in adhering the plaque bacteria as well as the acid on to the tooth surface.
  • S. mutAns can adhere and grow on hard and smooth surfaces of the teeth.
• Actinomycosis group, e.g., Actinomycosis israelii, Actinomycosis viscosus, etc. are the important organisms to cause root caries.
• Lactobacillus acidophilus is an important organism for the progression of dental caries.

“Role of Miller’s chemo-parasitic theory in understanding dental caries: Questions answered”

Role of Acids

• During the process of caries formation, a large variety of acids are produced in the oral cavity due to the bacterial fermentation of dietary carbohydrate.
• These acids are lactic acid, aspartic acid, acetic acid, butyric acid, and glutamic acid.
• They can cause demineralization of enamel and dentin and causethe tooth decay.

Role of Bacterial Plaque

• Plaque is a thin, transparent fim produced on tooth surface and it consists of microorganisms suspended in salivary mucin, also contain desquamated epithelial cells, leukocytes and food debris, etc.
• The dental plaque helps in the initiation of dental caries by:
  • It harbors the cariogenic bacteria on the tooth surface.
  • It holds the acids on the tooth surface for a long duration
  • It protects the acids from getting neutralized by the buffering action of saliva.

“Early warning signs of issues addressed by understanding dental caries theories: Common questions”

Proteolytic Theory

According to this theory, the proteolytic enzymes liberated by cariogenic bacteria destroysorganic matrix of enamel, as a result of which the inorganic crystals of the enamel become detached from one another, and finally the whole structure collapses, leading to cavity formation.

This theory cannot explain the role of sucrose, pH, fluoride, etc.,, in dental caries.

Proteolysis-Chelation Theory

• According to this theory during caries, fist of all pro­teolytic breakdown of the organic portion of the enamel matrix takes place.
• Following this, a chelating agent is formed by the combination of the proteolytic breakdown products, acquired pellicle, and food debris, etc.
• Chelating agents (negatively charged) release the calcium ion (positively charged) from enamel and dentin; this process is called chelation and eventually results in tooth decay.

“Differential applications of classical vs modern dental caries theories: Questions answered”

Sucrose Chelation Theory

• This theory proposes that if there is a very high concentration of sucrose in the mouth, there can be formation of complex substances like calcium saccharide and calcium complexing intermediaries can be formed.
• These complexes cause the release of calcium and phosphorus ions from the enamel and thereby result in tooth decay.

“Asymptomatic vs symptomatic effects of ignoring dental caries theories: Q&A”

Autoimmune Theory

This theory suggests that a few odontoblast cells at some specific sites, within the pulp of a few specific teeth, are damaged by autoimmune mechanisms.

Current Concept of Caries Etiology

• Dental caries is a multifactorial disease in which there is interplay of three primary factors—the host, microflora, and the substrate. In addition a fourth factor, i.e. time.
• Caries formation requires a host, a cariogenic flora, and a suitable substrate that must be present for a sufficient length of time.