Dental Caries Health Article

Definition

Dental caries, also known as tooth decay, is the destruction of the outer surface (enamel) of a tooth. Decay results from the action of bacteria that live in plaque, which is a sticky, whitish film formed by a protein in saliva (mucin) and sugary substances in the mouth. The plaque bacteria sticking to tooth enamel use the sugar and starch from food particles in the mouth to produce acid. Tooth decay can result in tooth loss.

Description

Thanks to the benefits of fluoride and fluoridated water, dental caries, also called dental cavities, are not as prevalent as in the years before and including the 1980s. While the majority of senior citizens a generation ago lost all their teeth, the vast majority of the elderly today have some or all of their natural teeth.

Although anyone can have a problem with tooth decay, children and senior citizens are the two high-risk groups. While both groups experience a diminishing caries rate, senior citizens are getting more cavities than children. Since older adults are keeping their teeth longer, they have become more prone to root caries, or root decay. Other high-risk groups include people who eat a lot of starchy and sugary foods, people living in areas without a fluoridated water supply, and people who already have numerous dental restorations (fillings and crowns).

Baby bottle tooth decay

Baby bottle tooth decay is a dental problem that frequently develops in infants who are put to bed with a bottle containing a sweet liquid. Baby bottle tooth decay is also called nursing-bottle caries and bottle-mouth syndrome. Bottles containing liquids such as milk, formula, fruit juices, sweetened drink mixes, and sugar water continuously bathe an infant's mouth with sugar during naps or at night. The bacteria in the mouth use this sugar to produce acid that destroys the child's teeth. The upper front teeth are typically the ones most severely damaged, the lower front teeth receiving some protection from the tongue. Pacifiers dipped in sugar, honey, corn syrup, or other sweetened liquids also contribute to bottle-mouth syndrome. The first signs of damage are chalky white spots or lines across the teeth. As decay progresses, the damage to the child's teeth becomes obvious.

Causes and symptoms

Tooth decay requires the simultaneous presence of three factors: plaque bacteria, sugar, and a vulnerable tooth surface. Although several microorganisms found in the mouth can cause tooth decay, the primary disease agent appears to be Streptococcus mutans. The sugars used by the bacteria are simple sugars such as glucose, sucrose, and lactose. They are converted primarily into lactic acid. When this acid builds up on an unprotected tooth surface, it dissolves the minerals in the enamel, creating holes and weak spots (cavities). As the decay spreads inward into the middle layer (the dentin), the tooth becomes more sensitive to temperature and touch. When the decay reaches the center of the tooth (the pulp), the resulting inflammation (pulpitis) produces a toothache.

The elderly are more prone to dental caries because more than 95% of senior citizens have lost some of the gum tissue that protects the tooth roots, exposing the roots to plaque and decay. It also is common to see decay around filling margins. Over time, fillings tend to weaken, fracture, and leak around the edges, which fosters the accumulation of bacteria. Another reason that the elderly get more cavities is that many take medications that reduce saliva, which naturally protects the teeth from caries.

Chewing tobacco is another culprit that increases the risk of tooth decay. A study showed that men who use chewing tobacco are four times more likely to have one or more decayed or filled root surfaces, compared to those who had never chewed tobacco.