Fluoride intake of children: considerations for dental caries and dental fluorosis.

Caries incidence and prevalence have decreased significantly over the last few decades due to the widespread use of fluoride. However, an increase in the prevalence of dental fluorosis has been reported simultaneously in both fluoridated and non-fluoridated communities. Dental fluorosis occurs due to excessive fluoride intake during the critical period of tooth development. For the permanent maxillary central incisors, the window of maximum susceptibility to the occurrence of fluorosis is the first 3 years of life. Thus, during this time, a close monitoring of fluoride intake must be accomplished in order to avoid dental fluorosis. This review describes the main sources of fluoride intake that have been identified: fluoridated drinking water, fluoride toothpaste, dietary fluoride supplements and infant formulas. Recommendations on how to avoid excessive fluoride intake from these sources are also given.

Systemic fluoride.

There is substantial evidence that fluoride, through different applications and formulas, works to control caries development. The first observations of fluoride's effects on dental caries were linked to fluoride naturally present in the drinking water, and then from controlled water fluoridation programs. Other systemic methods to deliver fluoride were later suggested, including dietary fluoride supplements such as salt and milk. These systemic methods are now being questioned due to the fact that many studies have indicated that fluoride's action relies mainly on its post-eruptive effect from topical contact with the tooth structure. It is known that even the methods of delivering fluoride known as 'systemic' act mainly through a topical effect when they are in contact with the teeth. The effectiveness of water fluoridation in many geographic areas is lower than in previous eras due to the widespread use of other fluoride modalities. Nevertheless, this evidence should not be interpreted as an indication that systemic methods are no longer relevant ways to deliver fluoride on an individual basis or for collective health programs. Caution must be taken to avoid excess ingestion of fluoride when prescribing dietary fluoride supplements for children in order to minimize the risk of dental fluorosis, particularly if there are other relevant sources of fluoride intake - such as drinking water, salt or milk and/or dentifrice. Safe and effective doses of fluoride can be achieved when combining topical and systemic methods.

Tooth loss in the very old: 13-15-year incidence among elderly Iowans.

OBJECTIVES: Very few studies have reported tooth loss incidence over a period of 10 years or more, and fewer have reported tooth loss occurrence in subjects aged 80 and older, so that the long-term pattern of tooth loss in the very old is largely unknown. This study assessed 13-15-year tooth loss incidence among a cohort of Iowans, aged 65 and older at baseline. METHODS: Oral examinations were conducted on 520 subjects beginning in 1983, and periodically until 1988, with another round of examinations conducted on surviving members of the initial cohort during 1996-98. RESULTS: Of the 73 remaining subjects, 45 subjects lost a total of 153 teeth during the period (mean=2.1 teeth lost), with a maximum of 17 teeth lost. Molars were the most commonly lost teeth, while canines and maxillary incisors were the least commonly lost. Bivariate analyses found that tooth loss was associated with untreated decay at baseline and level of periodontal attachment loss at earlier examinations. Logistic regression identified only greater severity of attachment loss as a significant risk factor for tooth loss (Adjusted odds ratio=2.4, P=0.006). The impact of tooth loss on subjects' lives was assessed using OHIP and other questions. The occurrence of tooth loss over the study period had little impact, but the number of remaining teeth significantly impacted subjects' ability to eat or chew food, swallow, or their willingness to smile. CONCLUSIONS: These results suggest that tooth loss continues in the very old, that periodontal attachment loss is associated with tooth loss in this age group, and that loss of teeth over one's lifetime does affect certain quality-of-life measures.