Dental Caries

Now the importance of brushing & flossing comes here.



Before we explain dental caries, we have to know the difference between plaque and calculus (tartar), and we have to know what is the anatomy of our teeth.

Plaque is the sticky, colorless film that constantly forms on your teeth. Bacteria live in plaque and secrete acids that cause tooth decay and irritate gum tissue. This irritation causes an inflammatory reaction by your body that can eventually lead to gingivitis and periodontal disease. If plaque is not removed regularly by tooth brushing and flossing, it hardens to create calculus (also known as tartar). Calculus cannot be removed with a toothbrush; only a dental professional can remove it during an oral cleaning. To keep plaque and calculus under control, it is essential to brush your teeth twice every day, floss at least once every day, and see your dental professional for regular cleanings.

Reference: American Academy of Periodontology

See Figure (1)

Figure 1

Briefly, our teeth consists of Enamel which is hardest structure in our human body and is the visible portion in the oral cavity. Beneath the Enamel, another layer of hard tissue (but less harder than Enamel) called the dentin and its consists of tubes that connect with the third layer called the Pulp which is a soft tissue containing nerves, blood vessels, and lymphatics. See Figure (2).

The Tooth Anatomy
The Tooth Anatomy. Figure 2

After we brush our teeth with a fluoride toothpaste, an adsorbed layer of glycoprotein from the saliva called the pellicle is attached to our teeth within a few seconds. After 2 hours bacteria adhere to that layer and after 24 hours, the bacteria have multiplied and comprised of up to 95% of the total cultivable flora of the mouth.

In order for caries to occur, there are certain factors that cause them.

The principal factors are:

  1. Plaque with Bacteria
  2. Substrate (Food Material)
  3. Susceptible tooth surface
  4. Time

These factors should be combined all together for caries to occur. (Figure 3)

Figure 3

Plaque is important in the etiology of dental caries because acid generated within its substance to such an extent that Enamel may be dissolved. Dietary sugars diffuse rapidly across the plaque together with high population of bacteria causes a rapid decrease of the pH of the plaque within 10 minutes (Critical pH). In this critical pH, caries might occur. However, if we have a good oral hygiene, the pH of the plaque may slowly rise to its original figure some 30 to 60 minutes later. Diffusion of the sugar and some of the acid will be from the plaque to the outside and diffusion of buffered saliva into the plaque.

After that, a reprecipitation of minerals from saliva is aided by fluoride, calcium and phosphorus.

On the other hand,  if an individual is having a poor oral hygiene, caries may occur at that critical pH. The bacteria will dissolve the enamel followed by the dentin until bacteria reach the pulp (tissue nerve) where it contains nerves, lymphatics and blood vessels. Pain can occur even if the bacteria didn’t reach the pulp because as soon as dentin is involved in the dissolving process, chemicals like acids generated from the bacteria may pass down to the pulp causing irritation –> inflammation –> & eventually pain.

Now the question that might asks itself, why a person with good oral hygiene have a minimum amount of plaque/caries when compared with a person with poor oral hygiene? Simply because a person with poor oral hygiene will have bulky plaques that will interfere with outward diffusion of acid and an inward diffusion of buffered saliva.

  • Prevalence

Caries prevalence occurs when people are in exposure to sucrose rich diets because sucrose is the principal criminal and all studies criminates it for causing caries.

Most importantly, the frequency of sugar intake is far more important than the total amount consumed thus reducing the ingestion of sweets and sugary contents is recommended.

Caries may occur commonly in the upper teeth, why? because the lower teeth are protected by the action of tongue and saliva while our upper teeth are not. As saliva serves as barrier, thus it prevents caries. Diet with high fats and proteins also have a protective effect in the oral cavity.

  • Detection of Caries


Caries lesions may vary from yellowish or light brown, through mid-brown to almost black. Thus if you see any of these colors on your teeth, its better to consult your dentist as he is the only one to confirm that you have caries. Schedule your appointment with him as early as possible to prevent difficult treatment and serious complications (Figure 4 & 5). Your dentist may use a combination of clinical examination techniques and radiographs to determine the best treatment for you.

Figure 2
Figure 4
Figure 3
Figure 5
  • Prevention

A simple preventive measure is to follow the following procedures:

  1. Brush your teeth twice a day and everyday for 2-3 minutes & change the toothbrush every 3 months.
  2. Scrub your tongue using your toothbrush or a tongue scraper.
  3. Floss your teeth once a day and everyday.
  4. Visit your dentist to have your teeth checked and cleaned every 6 months (twice a year).

Many people will ask why to visit the dentist every 6 months? Basically, some areas on your teeth are not accessible for cleaning by a toothbrush & to prevent caries on your teeth, visiting a dentist every 6 months is highly recommended.

By following these rules, you will have a long-life natural teeth and a beautiful smile.

  • Summary

To summarize all this, caries may occur on any teeth and on any surface. Generally speaking, bacteria that live in the plaque secrete acids that will dissolve away the enamel. After a few days, it will involve the dentin causing an inflammatory reaction of the tooth by the pulp. Later, it will invade the pulp and may cause pulp death. After pulp death, the bacteria might keep multiplying in the pulp without any notice from the patient. Because the pulp is dead, the patient cannot feel any pain and he may think that the problem is resolved by itself. However, the absence of pain is not an indicative of healing, instead it may indicate that the pulp is dead and the bacteria is multiplying freely inside the tooth. After a while where the bacterial population is very high, it may leave the tooth from a small opening at the apex of the tooth’s root and will spread out in the body, at that time the body may not be able to fight the infection due to the huge amounts of bacterial populations thus it will results in serious complications especially those with prosthetic heart valves and implants as these bacteria may accumulate around these artificial materials and cause a lot of problems in the future.

Reference: Edited with respect to Dental Caries and Caries Diagnosis Handouts of Dr. Raghad Hashim, Associate Professor and the Head of Growth and Development Department at Ajman University of Science & Technology.

Now i want to hear from you!

Have you ever experienced dental caries? and what did you do to treat it?

I read each and every comment.

Haider Maitham, DDS


One thought on “Dental Caries

  1. A caries is an irregularity in the contour and line of curvature. You need to look past the colour (stain) of the tooth in order to realise you truly have caries and in correspondence treat the object that has subjected you to harm’s way. I’ve had the experience of paying the hefty bill of a dentist or the seven pounds of flesh as it were in Shakespeare’s time only for him to tell me that my anxiety centered over a simple stain, of which he would take the full responsibility of perishing from the white colossality of my dentition, and would not take no for an answer. I answered him well sir if you must, it is your job and I cannot deter the beckoning of a man’s nature unless so foretold by Heaven’s will. To which he applied the full force of his swishing probe and bye-bye old carious soulmate, Your defects that have so long complemented my own are not to eyed anymore. In the end it was the simple matter of taking care of my teeth and from now on I think I won’t drink as much Cola or smoke as much cigarettes. Thanks Dr. Hayder.

    Liked by 1 person

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