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4. Tooth Decay : Your Most Common Enemy

Contributed by:

Prof. Dr. Ishak Abdul Razak

Dept. of Community Dentistry University of Malaya Kuala Lumpur

An important indicator of oral health (or more precisely oral diseases) is the number of people with tooth decay (dental caries). In Malaysia, studies have shown that more than 70% of children of twelve years of age suffered from dental decay. The occurrence is much higher among adults as indicated in a national dental survey in Malaysia in 1990. About 9 out of 10 adults have at point in their life suffered from dental caries. There is not much difference in the pattern of disease between adult males and females as well as in the urban and rural areas. By the time the adults reached retirement age many had become completely toothless. One in every there adults in the age-group 55-64 were found to have no natural teeth. This proportion increases in the older age groups. It should be noted however that the younger generations are showing better dental health status than their predecessors. with this improvement it can be expected that the nation's overall dental status will have more bite in the future.

Whilst tooth decay is not life threatening, the impact on the individual and society is very significant. One of the most important consequent of tooth decay is pain and it is one of the most common type of experienced in the general population. For the general population in Malaysia, the number of people who experience pain and discomfort in and around the mouth are among those who seek dental treatment was reported to be up to 24% and toothache accounted for most of these. It should be noted that however that this figure represents just the tip of the iceberg, as the actual number of people with tooth decay were greater than those who sought treatment.

Treatment is often sought only when the pain becomes unbearable. The economic impact of tooth decay is also tremendous. About 5 - 6% of the budget that is allocated yearly for the health sector by the government goes towards financing the dental services. This does not include the amount of money spent seeking dental care in the private sector. Other economic impact includes the loss of schooldays and workdays as well as the reduction in the workers' productivity.

What is tooth decay?

Tooth decay is a disease which results in the destruction of the hard tissues of the tooth caused by acid. Initially it results in the softening of the outer surface of the tooth (enamel) which is often hidden from sight in the grooves on the biting surfaces or between the teeth. The destruction then spreads at a variable but slow rate into the softer and more sensitive part of the tooth (dentine ) beneath the enamel. Once the enamel is greatly weakened. it will then collapse to form a cavity and the tooth is progressively destroyed. Decay can also attack the roots of teeth should they become exposed by gum recession as a result of periodontal (gum) disease. Because the root surface is much softer than the crown the damage can be more extensive.

What are the causes of tooth decay?

Four important ingredients are necessary in order to produce tooth decay. These are firstly, a susceptible tooth surface, secondly, bacteria and thirdly, sugar. The fourth factor is time. The bacteria and sugar must meet on the tooth surface and remain there for a sufficient length of time for the damages to occur. All these ingredients must be presence simultaneously before the decay can set in.

Before the decay can be initiated the bacteria need to accumulate or colonize on areas of the tooth sheltered from the effects of ineffective toothbrushing. This colonization produces a film of bacteria on the tooth surface known as a dental plaque. Before the disease can progress at a significant rate the bacteria require the presence of sugar in the plaque. Tooth decay results from the action between several types of bacteria which form part of the normal flora of the mouth and sugar, the two coming together in the dental plaque. The sugar is broken down by the bacteria to produce acid which results in the dissolution of the tooth surface. The bacteria need not use all sugar available. Any access sugar will be stored by the bacteria in the plaque. This can later be broken down to produce acids when the free sugar is no longer available.

Initially, the acids produced will result in a small amount just beneath the tooth's surface. This process is called " demineralization " whereby calcium and phosphate ions are removed from tooth. However, at this stage the surface itself remain intact. Following this, the saliva then attempts to neutralize the acid and then wash away the sugar and begins to repair the damage and promote healing by replacing the lost calcium and phosphate ions. This process is known as " remineralization ". This healing process is accelerated by the presence of fluoride. Thus, the early decay process is a reversible process and may be seen as a contest fought at the tooth surface between on the one hand, the acids (produced by the interaction of bacteria and sugar) causing demineralization of the tooth surface and remineralization on the other hand. If the demineralization process exceeds that of remineralization then decay will result causing the surface of the tooth to eventually break down and a cavity to appear.

If the decay is allowed to progress unimpeded it will advanced from the outer to the inner parts of the tooth. Eventually the pulp (the core of the tooth that contains the cells, nerves and blood vessels) will become involved and eventually leading to the death of the tooth.

Some people's teeth are more resistant to attack than others and fluoride is the only factor that have been shown beyond doubt to decrease the susceptibility to decay. The effect of fluoride is due partly to its incorporation into the developing tooth before its eruption into the mouth and partly to its direct contact with the tooth after eruption into the oral cavity. The later is now thought to be the most important.

How to break the chain of tooth decay?

There are several actions that you can take to help break the chain of tooth decay in your mouth :

  • Cut down on the amount of sugar you eat each day. Limit your eating of sweets and sugar to meal time.
  • Use a fluoridated toothpaste.
  • Carefully clean your teeth twice a day (especially before bedtime) with toothbrush and floss.
  • Ask your dentist ifyou need to have fluoride applied to the surfaces of your teeth or if you need to have the grooves on your teeth sealed with preventive resins. If you already have tooth decay, have your dentist attend to it immediately to prevent further destruction of the tooth. Even if the decay has involved the pulp, your dentist can still save your tooth by doing root canal therapy.

Start breaking the chain of tooth decay and keep it up everyday so that you will have healthy teeth all your life!


Malaysian Dental Association shall ensure that the collection, use and disclosure of your personal data is consistent with the Malaysian Personal Data Protection Act 2010 ( 'PDPA' ). It is acknowledged that personal data collected and processed is obtained voluntarily and with your consent.

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