(1) A suitable carbohydrate substrate,
(2) bacteria present in plaque,
(3) a susceptible tooth surface,
(6) saliva and (7) fluoride are modifying factors.
There are 3 levels of preventive dentistry:
PREVENTION Step One is to prevent the transmission of the caries causing bacteria (Streptococcus mutans = 'sugar bugs') and delay their establishment in infants, toddlers, and young children. Studies show that these bacteria are transmitted vertically, from the child's primary caregiver(s), AND horizontally, from other family members, such as siblings, and peers. The higher the count of bacteria present in the caregiver's mouth, the more risk for the child. Also, the earlier the bacteria are introduced into the child's mouth and the greater number of bacteria present, the more likely it is that caries will develop in both primary (baby teeth) and permanent dentition. The "window of infectivity" of S. mutans is usually between ages 19 months and 31 months. For these reasons, education of the parents and other caregivers is extremely important and constitutes a major part of your child's first dental visit, at no later than one year of age.
PREVENTION Step Two prevents, arrests, or reverses the microbial shift before any clinical signs of the disease, caries, occur. Now, the caries causing bacteria are established in the mouth. In those areas where plaque accumulates and is often missed during home care, the bacteria count is higher. These areas are generally the pits and fissures in the back teeth, between teeth that are in close contact and at the gum-line of almost all dentition. Removal of dental plaque, whether daily at home or professionally at the office prevents and arrests demineralization (loss of calcium and phosphate) of the underneath enamel, and fluoride application arrests and even reverses the susceptibility of enamel to decay. During your child's dental visit, your pediatric dental team will evaluate your child's oral hygiene, assess their individual caries risk, and provide education on effective plaque removal. Newly erupted teeth are more porous and go through a post-eruption secondary maturation, during which enamel becomes fluoridated and more acid-resistant. Infants, especially, benefit from in-office fluoride varnish application since their teeth have limited exposure to fluoride, another reason why first dental visit by first birthday is a major part of prevention.
PREVENTION Step Three focuses on limiting or stopping the progression of the caries process by initiating remineralization therapy of existing lesions. Demineralization, or loss of minerals calcium and phosphate, occurs when the saliva pH drops from a neutral level of 7 to an acidic level of 5 and lower. Acid conditions come about when refined carbohydrates are introduced into the oral cavity, S.mutans ('sugar bugs') present in the mouth consume the carbohydrates and produce lactic acid. Common reasons for prolonged acid conditions include: increased carbohydrate intake, reduced clearance of lactic acid due to low saliva content, biofilm/plaque accumulation due to insufficient oral hygiene care, and presence of teeth with cavities. The more 'sugar bugs' present, the more acid produced, the more demineralization.
Remineralization, or regaining of minerals, occurs when saliva is released in the oral cavity returning the pH to the neutral level of 7. It is also important that minerals calcium, phosphate and fluoride are locally available to enamel for uptake. The balance between demineralization and remineralization is crucial. If demineralization occurs too frequently, then an incipient lesion (also referred to as a 'white spot' or 'start of a cavity') will occur. Incipient lesions may take up to 9 months or more to be seen and diagnosed in an x-ray. Early establishment of a dental home, followed by routine dental visits (frequency determined through customized caries risk assessment), will ensure early detection and treatment of incipient lesions, thus preventing cavities.
For more information on preventive dentistry visit aapd.org or ada.org.