Prenatal Care, pregnancy & oral health

Objectives: Participants will...

• Learn about appropriate timing for routine oral health care for pregnant women and be able to refer accordingly.
• Understand the cause, effect and prevention of plaque accumulation and be able to explain it to the expectant mother
• Be able to recognize pregnancy gingivitis, allay fears it engenders and provide some relief to the expectant mother who appears with it.
• Be advised to avoid prescribing tetracycline to mother or newborn while baby’s teeth are developing.
• Counsel expectant mothers about tobacco cessation and drug use.
• Have the know-how to prepare mother-to-be and new mother for her baby’s oral health.

It is usually safe to receive dental treatment at any time during pregnancy. The health history and physician/dentist consultation will help decide the best time to schedule dental care and whether care needs to be modified in specific cases. The dentist should be alerted to any drugs or medications the pregnant woman is taking to avoid contraindications or untoward side-effects. If non-emergency treatment is needed, it is wise to schedule it for the second trimester, i.e. fourth through the sixth month. Dental radiographs, needed to detect problems not visible clinically, are safe when a lead apron is used for protection. It is preferred that local anesthesia without epinephrine be used so as not to compromise blood supply to the fetus.

Tooth buds appear in the fetus in the 5th or 6th week of pregnancy. Tooth formation and eruption proceed according to an established pattern (see next chapter). Counseling a mother-to-be on care of her own teeth and general health and arranging for her to get an adequate amount of vitamins A,C,D, calcium and phosphorus will help to ensure the oral health of her newborn baby. Lack of calcium, phosphorus and other essentials minerals and vitamins can lead to hypoplastic enamel in the unborn baby’s dentition and to subsequent early childhood caries. Folic acid deficiency has been implicated in the development of birth defects. Avoid prescribing tetracycline during pregnancy or to the infant during the first three months; it causes discoloration of the primary teeth. Tetracycline stain of permanent teeth occurs between birth and eight years.

Tobacco cessation is critically important during pregnancy, as it has been associated with preterm and low birth weight delivery (PTLBW). It has also been associated with an increase in SIDS, asthma and other developmental problems when second hand smoke is around infants and toddlers.

It is not true that a tooth is lost with every pregnancy. Only neglecting oral hygiene, i.e., not removing plaque which constantly forms on teeth and gums, not using adequate fluoride, and too frequent snacking on foods containing fermentable carbohydrates (starches) or sugars, whether visible or hidden, will result in caries and gingivitis.

Plaque, the sticky colorless film made up of bacteria and bacterial products should be removed, preferably twice a day, at night before going to sleep and after breakfast. Bacterial products (acids and toxins) cause caries and gingival inflammation.

During pregnancy, the hormonal changes which occur naturally exaggerate the response of the gingiva to the local irritants in the plaque resulting in “pregnancy gingivitis.” Gingival changes usually appear during the second trimester. In the absence of local plaque build up, clinically healthy gingiva will not show changes during the altered hormonal periods. Recent research suggests that women with periodontal disease that existed prior to the pregnancy may also have significantly higher rate of preterm and low birth weight infants.

Risk factors for PTLBW delivery include alcohol and drug use, smoking, poor nutrition and periodontal disease. Pre-term, low birth weight or malnourished infants are more likely to have hypoplastic teeth, which, tend to foster bacterial colonies and subsequently to result in early childhood caries.

Pregnancy Gingivitis.

Preterm and low birthweight babies: studies have shown a relationship between periodontal disease in the mother and increased chances of delivering a premature or low birthweight baby. Women with periodontal disease may be 7 times more likely to have a baby that is too early and too small. Many women do not know that they have a periodontal infection, so an assessment prior to or early in pregnancy is a good idea.

Diabetes: people with diabetes are more likely to have periodontal disease, and having periodontal disease makes it more difficult to control one’s blood sugar. Diabetics have a decreased healing response. A diabetic pregnant woman must take extra precautions to be sure her periodontal disease in continually monitored and under control.

Heart disease and stroke: Periodontal disease increases the risk that bacteria will enter the blood stream and travel to major organs and begin new infections. Research suggests that this may contribute to the development of heart disease, the nation’s leading cause of death, and increase the risk of stroke.

Since caries is an infectious disease, the opportunity to reduce the cariogenenic bacteria should be viewed as critical in preventing ECC. Therefore, any carious lesions noted during pregnancy should be treated as soon as possible.

Benefits of fluoride and understanding dental caries

Objectives: Participants will...

• Understand the role of fluoride in inhibiting demineralization and enhancing remineralization of enamel tooth structure, thus preventing decay.
• Learn the newly recommended schedule for dietary fluoride supplementation.
• Understand that frequency of eating is the significant factor in caries development.

Over a century ago, in 1892, Sir James Crichton suggested that the specific cause of an increase in dental caries was a change in the type of bread eaten – i.e., a deficiency in the fluorine present in the bran or husk parts of wheat. Numerous studies demonstrate effectiveness of fluoride in caries prevention and decline of dental health on cessation of water fluoridation.

Fluoride has played a major role in the marked reduction in caries incidence and prevalence. Under normal conditions there is a constant exchange of ions between the enamel surface and the surrounding saliva, resulting in a dynamic equilibrium. This equilibrium is disturbed when organic acids are produced by bacterial metabolism of fermentable carbohydrates. The acids lower the ph of plaque fluid on the enamel surface, penetrate the enamel subsurface, and then cause enamel crystals to dissolve and leave the enamel. This process is called demineralization.

Today, scientists agree that maintaining fluoride at and within the enamel surface of the teeth is an important factor in determining whether an early carious lesion, i.e., a demineralized area of the tooth, will progress to a cavity or will be remineralized.

Dental caries is an infectious disease with multifactorial etiology. It is clear that four components are necessary for its causation – the tooth, omnipresent bacteria (especially mutans streptococci), fermentable carbohydrate in the saliva and time. Elimination of one or more of these factors would foil the process. Simply stated, the bacteria present in the mouth need fermentable carbohydrate (sugar in any form) to manufacture a steady stream of acid and to cause demineralization. An acid demineralized area of a tooth appears as a white spot. If detected early enough, the white spot lesion on the enamel can be healed (remineralized) with the use of fluoride. In fact, the single most important factor in cavity prevention is daily exposure of the teeth to small quantities of fluoride. The presence of fluoride ions on or in the enamel surface can inhibit or reverse this process. In other words, fluoride ions in saliva protect against demineralization and facilitate remineralization.

The frequency of eating has a more significant effect on the development of caries than what is eaten. Because of this, the habit of infant nursing throughout the night or sleeping with a bottle without preventive techniques puts the infant at risk for ECC.

In the United States, community water fluoridation is recommended at a concentration ranging from 0.7 to 1.2 parts per million (ppm) of fluoride, depending upon the community’s mean maximum daily temperature. New York City water is fluoridated at 1.0 ppm.

Fluoridated drinking water acts both systemically and topically. Other forms of topically applied fluoride include professionally applied and self applied fluoride treatments, fluoride dentifrices, fluoride mouthrinses, and fluoride varnishes.

Dietary fluoride supplements are prescribed by practitioners for children living in areas with a suboptimal level of fluoride in the drinking water. They are administered either as drops or tablets with or without vitamins. However, before prescribing a fluoride supplement, a physician or dentist should know the child’s age and the concentration of fluoride in the child’s “primary” source of drinking water. (Note: the “primary” water source is often not the child’s “home” water source).

ADA/AAPD Recommended Supplemental Fluoride Dosage Schedule

Dosages are in milligrams F/day

Improper use of dietary fluoride supplements and ingestion of fluoride dentifrices by small children, particularly in fluoridated communities, may result in dental fluorosis. Dental fluorosis is defined as hypoplasia or hypomaturation of tooth enamel produced by chronic ingestion of excessive amounts of fluoride as the teeth are developing, and are manifested as whitish opacities on the teeth. In severe cases, mottled enamel may occur.

Although fluoride ingested by mother can cross the placenta, for lack of conclusive evidence that it will reduce dental caries in her offspring, prenatal fluoride supplementation for the expectant mother is not recommended.

Fluoride varnishes have been used in Europe for more than 30 years, and have recently been approved for use in the United States. It is a most promising product for the prevention of tooth decay due to its unique properties of remaining in contact with tooth surfaces for extended periods of time and setting to a hard coating on tooth enamel even in the presence of moisture.

There are fluoride varnishes available for use in the United States.  Most commonly they contain 5% sodium fluoride. When applied, the varnish forms a sticky layer on the tooth, which hardens on contact with saliva.  Fluoride is then absorbed into the enamel of the tooth.  It is recommended that the varnish be allowed to remain on the teeth for up to four hours for optimal absorption.  

Most studies have shown 25-45% reductions in the decay rate with the use of fluoride varnish.  Of special note is the reduction of decay in pits and fissures (the biting surfaces of molars), as well as on smooth surfaces of teeth.  A two-year study by Holm resulted in a 44% caries reduction rate following semi-annual varnish applications.

Although the concentration of fluoride in varnishes is much higher than that of APF gels or other topical fluorides, due to the sticky form of the varnish and the small amount used per application, risk of ingestion and toxicity is very low. This most promising fluoride product will become the preferred method of application of topical fluoride in the years to come.