Primary teeth or Deciduous teeth, otherwise known as reborner teeth, baby teeth, temporary teeth and primary teeth, are the first set of teeth in the growth development of humans and many other mammals. In some Asian countries they are referred to as fall teeth as they will eventually fall out, while in almost all European languages they are called milk teeth as they exist when the child is still mainly drinking milk. They develop during the embryonic stage of development and erupt—that is, they become visible in the mouth—during infancy. They are usually lost and replaced by permanent teeth, but in the absence of permanent replacements, they can remain functional for many years.
Deciduous teeth start to form during the embryo phase of pregnancy. The development of deciduous teeth starts at the sixth week of development as the dental lamina. This process starts at the midline and then spreads back into the posterior region. By the time the embryo is eight weeks old, there are ten areas on the upper and lower arches that will eventually become the deciduous dentition. These teeth will continue to form until they erupt in the mouth. In the deciduous dentition there are a total of twenty teeth: five per quadrant and ten per arch. The eruption of these teeth begins at the age of six months and continues until twenty-five to thirty-three months of age. Usually, the first teeth seen in the mouth are the mandibular centrals and the last are the maxillary second molars.
The deciduous dentition is made up of central incisors, lateral incisors, canines, first molars, and secondary molars; there is one in each quadrant, making a total of four of each tooth. All of these are gradually replaced with a permanent counterpart except for the first and second molars; they are replaced by premolars. The replacement of deciduous teeth begins around age six. At that time, the permanent teeth start to appear in the mouth, resulting in mixed dentition. The erupting permanent teeth causes root resorption, where the permanent teeth push down on the roots of the deciduous teeth causing the roots to be dissolved and become absorbed by the forming permanent teeth. The process of shedding deciduous teeth and the replacement by permanent teeth is called exfoliation. This may last from age six to age twelve. By age twelve there usually are only permanent teeth remaining.
Teething age of deciduous teeth:

• Central incisors : 6–12 months
• Lateral incisors : 9–16 months
• Canine teeth : 16–23 months
• First molars : 13–19 months
• Second molars : 22–33 months

Primary teeth care

Proper care of deciduous teeth is very important and starts at early stages even prior to their eruption. At the earliest stage, a child’s mouth and gums are to be wiped with a clean damp cloth, gauze pad, or especially designed teeth wipes. Wiping the baby’s teeth and gums after each feeding, and particularly at bedtime, helps prevent baby bottle tooth decay. This practice also helps reduce premature decay caused by harmful plaque-like film and bacteria that builds when babies ingest juices or any food containing sugar.  Moreover, to reduce the possibilities to develop baby bottle tooth decay is it better to give the baby only plain water at bedtime or during the night and avoid juices, sugar water, milk or any other liquid containing sugar.

Once the first primary teeth come in, brushing starts. Warm water is normally used in these cases or a non fluoride toothpaste. The market offers special toothbrushes or finger toothbrushes for babies that help protect tender gums and gently clean baby teeth and gums. Other toothbrushes are specially designed for toddlers to easily grip them. They also come in catchy designs that encourage toddlers to use them. Toothbrush designs vary according to age, therefore, it is better to check the age recommendation on the package to obtain the most convenient one. Toothbrushes should be replaced every two to three months. It is also important to brush children’s teeth after giving them medicine as their acids may affect the tooth enamel. Early brushing helps reduce harmful bacteria, remove plaque, sugar, or any other kind of food that may cause tooth decay.

Parents are advised to take their children to the first dentist visit when they are 12 months old. During this visit, the dentist can define dental care plan. Two possible ways to prevent tooth decay are the use of fluoride and sealants.

Fluoride makes teeth stronger over time which then prevents the initiation of dental caries and tooth decay. Also, it re-mineralizes those areas of the teeth which have been weakened by acid. Fluoride can be included in one’s diet. Other ways of obtaining fluoride are in toothpastes and mouth rinses that are normally used at homes. The dentist can provide it through gels and foams he applies during dental visits.
To add to the benefits of the fluoride, dentists also apply sealant in order to preserve the teeth even more. Sealant is applied in some locations of the teeth that smooth their surface. Therefore, food and plaque are less likely to get trapped in those areas.
Children can start flossing when they are about 3-4 years old. However, at this age they might still need help and will be able to floss by themselves when they are 8-10 years old.