Dental Caries and Associated Issues

By Dr. Vishaal Bhat on Saturday, 29 December, 2007 with 0 comments

The dental caries is the most widespread disease in the population, it affects 80-90% of the population. The most remarkable feature of prehistorical findings of jaws is the teeth abrasion. The dental caries may already be found on teeth dating back to paleolith and mesolith. Until the end of the 17th century, the dental decay occurrence was rather small and its frequency continued to grow until the 18th century. The dental caries incidence is directly related to the food composition and means of preparation.

The origin of caries has not been satisfactorily explained yet. During certain periods the opinions on the dental caries origin reflected contemporary level of knowledge and they possess rather historical value these days. A group of exogenous - localistic - theories deem the cause for caries in external effects. The endogenous - vital - theories explain the origin of caries by the influence of endogenous factors.

Factors influencing appearance of the dental caries.

Occurrence of the dental caries depends on numerous endogenous and exogenous factors:

The saliva. The saliva is a product of both large and small salivary glands. Most of saliva is produced by the glandula submandibularis (40%) and glandula parotis (26%). Composition of the saliva is variable. More than 99% of it is made of water. The saliva contains 0.7% of solid substances, of those 0.5% are organic compounds and 0.2% inorganic compounds. Calcium is present in form phosphates and to the lesser extent as carbonate. The saliva further contains potassium, magnesium, chlorides, sulfate and some other elements, e.g. iodine. The amount of iodine in saliva is 20 to 100 times higher than in plasma which reflects the thyroid gland function. Carbon dioxide is an important part of the saliva as well, it acts as a buffer to maintain the saliva’s pH. Organic compounds of the saliva are represented by mucoids, albumins, globulins and peptides. Urea, uric acid, creatin and ammonia are present in low concentrations in saliva. Among the most important enzymes are amylase, esterase, lipase and peroxidase. Lysozyme is an important component as well. The saliva contains small amounts of erythrocytes, leukocytes from the gingival grooves and lymphocytes from the tonsils. However, phagocytotic ability of leukocytes from saliva is low.

Microorganisms of the oral cavity. A mixed microbial flora, both aerobic and anaerobic inhabits the oral cavity. Streptococcus mutans which forms 28 to 96% of the total microbial flora present in the dental microbial plaque, has the closest relationship with the occurrence of a dental caries. This relation is supported by its ability to produce acids and both intracellular and extracellular polysaccharides. Intracellular polysaccharides may be also produced by various strains of staphylococci, diplococci and rods. That is why the microbial flora in general is responsible for the dental caries origin, not just a single strain of microorganism.

Microbial plaque. This coating is one of the most important factors playing a role in the dental caries occurrence having also a relation to the origin and course of parodontopathies. The first stage of its development is the secondary cuticle which is made of salivary glycoproteins and covers teeth, fillings, crowns and dentures. At the early stages the cuticle contains cocci and short rods. The microbial plaque itself is made of the secondary cuticle, microorganisms and an intermicrobial substance. Some bacteria can produce glucanes and fructanes and promote the plaque growth even when no food is being consumed. Besides streptococci, a developed microbial plaque contains also actinomycetes (40-60%). The amount of plaque varies - most of it is present in the morning and after food ingestion. The plaque’s formation is linked to places that are habitually non-clean (i.e. places where the process of self-cleaning is restrained) - grooves of premolars and molars, cervical parts of crowns. According to its location, the plaque can be divided into fissural, supragingival, and subgingival. At the surface of the microbial plaque, there is materia alba that is made of the peeled off epithelium, leukocytes and food residues.

The dental calculus is formed by mineralization of the microbial plaque. It can be found in mouth especially around the large salivary glands ducts.

Food intake, nutrition, hereditary factors. The occurrence of caries is influenced by the presence of low-molecular saccharides from food, time intervals of a food ingestion and its composition. Concentration of sugar in saliva has a great influence, as well as the period of its activity. Food that is long-persistent and sticks to the teeth (honey, chocolate) has a negative effect. The origin of caries is not directly caused by genetic factors, although a predisposition to it is hereditary. Genetic factors are rather manifested by the teeth arrangement at some orthodontic anomalies. These abnormalities create a condition for easier deposition of the microbial plaque, thus causing caries and parodontopathies.

Category: Restorative Dentistry Notes



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