This a very common question. Many parents of children with cavities are concerned that their child’s teeth are soft, thus increasing their cavity risk. Many parents falsely blame their children’s poor dental health on “soft” teeth” Before we can answer this question we need to discuss the different tissues from which teeth are made.
Teeth are composed of four basic tissues:
- cementum, and
Enamel, dentin and pulp are the three tissues most commonly associated with cavities in children.
Enamel is a white, highly mineralized tissue similar in composition to bone, but much harder. Enamel is the hardest substance in the human body. Enamel forms the protective outer layer of the crown of the tooth that is initially attacked by the acid producing sugarbugs, or cavity-causing bacteria. The acids produced by these bacteria dissolve the enamel over time, until the tissue below is reached.
Dentin is the softer yellowish tissue of the tooth below the enamel and forms both the crown as well as the root of each tooth. This tissue layer is less mineralized than enamel, contains more protein, and more water than enamel, making it more susceptible to decay. Once cavities get to this tissue layer they progress more quickly toward the dental pulp, or the “nerve” of the tooth The further the cavities progress into the dentin, the more painful the tooth becomes.
The dentin inside the tooth forms a chamber containing nerves, blood vessels and tooth building cells. The tissue within the chamber is referred to as the dental pulp, or root canal. Once a cavity reaches the pulp, the pulp can become inflamed and eventually will become infected unless treatment is provided.
The root surface is covered with cementum. This is the softest of the three mineralized tissues which comprise our teeth. It is usually not visible in children or young adults. However, as we age, cementum can be exposed because of receding gums. It is a very sensitive tissue and will react painfully to physical or chemical stimulation such as toothbrushing or hot or cold foods. Most older adults have exposed root surfaces and exposed cementum.
So, in the vast majority of cases children with cavities do not have soft teeth. However, there are several genetic abnormalities, and abnormalities caused by illness, infection or malnutrition which may increase the risk for affected teeth to develop cavities. Any developmental changes affecting the surface roughness of the enamel, or the thickness of enamel and dentin can increase cavity risk by making the job easier for the bacteria accumulate on the surface or to penetrate into the tooth. Thankfully, these conditions are very uncommon. Parents may question if their child has either an inherited dental condition or acquired dental abnormality if the colour or shape of their children’s is different from what they expect If you think that your child is affected by one of these rare conditions, ask your dentist to examine your child.
As we have explained in previous columns, bacteria and our diet are far more important in the decay process.
What’s the bottom line? There are very few individuals out there who actually have “soft teeth”. Remember that teeth and bones are formed from the same minerals – calcium and phosphate. If your child has “soft teeth”, they will also likely have “soft” bones. Soft bones are susceptible to deformation or fracture. Your family physician will be very aware if your child has abnormal bones. Your dentist will be able to determine if your child has abnormal enamel or dentin.