Access to Fluoridated Water and Adult Dental Caries

Abstract

Systematic reviews have found no evidence to support a benefit of water fluoridation (WF) to prevent dental caries in adult populations. The aim of this natural experiment was to investigate whether lifetime access to fluoridated water is associated with dental caries experience among adults from Florianópolis, Brazil. The data originated from a population-based cohort study (EpiFloripa Adult) initiated in 2009 (n = 1,720) when participants were aged 20 to 59 years. The second wave was carried out in 2012 (n = 1,140) and included a dental examination and a face-to-face questionnaire. Participants residing at the same address since the age of 7 y or before were included in the primary analyses. Sensitivity analyses were also performed. WF was implemented in the city in 2 different periods of time: 1982 (60% of the population) and 1996. Dental caries was assessed by the decayed, missing, and filled teeth (DMFT) index. A combination of residential status, participant's age, and year of implementation of WF permitted the creation of participants' lifetime access to fluoridated water: >75%, 50% to 75%, and <50% of a participant's lifetime. Covariates included sex, age, socioeconomic mobility, educational attainment, income, pattern of dental attendance, and smoking. Participants who accessed fluoridate water <50% of their lifetime presented a higher mean rate ratio of DMFT (1.39; 95% CI, 1.05-1.84) compared with those living >75% of their lifetime with residential access to fluoridated water. Participants living between 50% and 75% and <50% of their lives in fluoridated areas presented a decayed and filled teeth mean ratio of 1.34 (95% CI, 1.02-1.75) and 1.47 (95% CI, 1.05-2.04) higher than those with residential access to fluoridated water >75% of their lifetime, respectively. Longer residential lifetime access to fluoridated water was associated with less dental caries even in a context of multiple exposures to fluoride.

Effectiveness of water fluoridation in the prevention of dental caries across adult age groups

“…There were strong age‐specific differences in residential access to water fluoridation and caries experience across the wide age range. We found a significant association of per cent lifetime access to water fluoridation and caries experience, which is comparable to that reported elsewhere . The magnitude of the association differed among birth cohorts or age groups.…”

“…Epidemiological evidence of the effectiveness of water fluoridation on dental caries experience in adults is relatively scarce. A population‐based cohort study in Brazil reported significant association between lifetime access to fluoridated water (FW) and dental caries experience in adults after adjusting for socioeconomic status and health behaviours . Such beneficial association was also found between access to FW and tooth loss .…”

Bioethical considerations about water fluoridation: a critical review

“…A natural experiment carried out in Brazil observed the relationship between access to fluoridated drinking water and its association with caries in adults 10 , concluding that access to fluoride water was associated with a lower prevalence of caries even with multiple exposures to fluoride during the course of life. Among the limitations noted by the authors, there are the small sample size and the fact that exposure to fluorides in water was assumed to be constant over the years, which can lead to errors in the estimation.…”

“…Fluoride is often added to drinking water as a way to reduce caries 10 . Since its implementation as a national policy, fluoridation of drinking water has had supporters who advocate the benefits of fluoridation in reducing the incidence and progression of caries.…”

Heterocontrole da fluoretação nos municípios da Região Metropolitana de Curitiba nos anos de 2014 e 2015

“…Estima-se que o poder preventivo da fluoretação seja em torno de 40 a 70% em crianças, reduzindo a perda dentária em adultos de 40 a 60% 4 . O benefício da fluoretação na prevenção da cárie dentária também está demonstrado em vários estudos [5][6][7][8][9] , e muitas entidades representativas de saúde recomendam a fluoretação, como International Association for Dental Research, European Organization for Caries Research, Organização Pan-Americana de Saúde, Organização Mundial da Saúde e World Dental Federation 10 . A fluoretação da água de abastecimento começou nos Estados Unidos em 1945.…”