DEPARTMENT OF HEALTH & HUMAN SERVICES Public Health Service Centers fr Disease Cntrl and Preventin (CDC) Atlanta GA 30341-3724 July 2, 2015 RE: Cmments Regarding the Cchrane Review f Water Fluridatin fr the Preventin f Dental Caries Dear Clleagues, In June 2015, the Cchrane Oral Health Grup released a publicatin n cmmunity water fluridatin. This review has attracted attentin because it appears t reach different cnclusins abut the effectiveness f this cmmunity-based interventin than the final Public Health Service (PHS) recmmendatin recently released by the U.S. Department f Health and Human Services (HHS). The Centers fr Disease Cntrl and Preventin s (CDC) Divisin f Oral Health wuld like t prvide sme clarificatin n this issue in rder t stress where key findings regarding the effectiveness f water fluridatin are in fact the same, and t explain where and why differences exist between the tw dcuments. Abve all, we want t assure yu that HHS maintains its cnfidence in water fluridatin as a valuable tl t prevent tth decay in children as well as adults, and views it as the basis fr the primary preventin f tth decay. The Cchrane review and the PHS recmmendatin bth identified reductins in caries in children s permanent and primary teeth assciated with cmmunity water fluridatin. Further, data frm natinal surveys cnducted in the U.S. cntinue t shw that the percentage f adlescents wh have tth decay has cntinued t decline acrss sci-ecnmic and racial and ethnic grups. Bth the Cchrane review and the PHS recmmendatin agree that dental caries cntinues t be a significant public health prblem, and HHS is cmmitted t reducing dental disease thrugh evidence based interventins such as cmmunity water fluridatin. In 2010, HHS cnvened a federal, interdepartmental, interagency panel f scientists t review the PHS 1962 recmmendatin that cmmunity water systems add fluride t their drinking water t prevent tth decay. The PHS review panel utilized the best available science in making their recmmendatins. The panel cncluded that water fluridatin remains a safe and effective strategy t reduce tth decay, and that it is the mst cst effective and feasible way fr cmmunities t address dental disease. One key difference between this review and the Cchrane review is that Cchrane used mre restrictive criteria fr including studies in their analyses. A cnsequence f their apprach was that studies included in the Cchrane review were primarily cnducted befre 1975. As a result, Cchrane fund insufficient infrmatin available t determine if water fluridatin had an impact in an envirnment where fluride prducts such as tthpaste are nw widely used. Althugh valid, peer-reviewed studies dcument the effectiveness f cmmunity water fluridatin in children and adults even after the use f fluride tthpaste became widespread, these studies were nt cnsidered by Cchrane. Anther factr that impacted Cchrane s assessment f the quality f the evidence is that their methdlgy favrs randmized cntrlled trials (RCTs). While RCTs are a preferred study design fr studies cmparing
different clinical treatments amng individual patients, this research design is ften nt feasible fr interventins that ccur n a cmmunity level, like cmmunity water fluridatin. A mre detailed cmparisn f the findings between the Cchrane reprt and the PHS recmmendatin alng with key references is attached. We hpe yu find this summary useful. Sincerely, Katherine Wen, DDS, JD Directr Divisin f Oral Health Natinal Center fr Chrnic Disease Preventin and Health Prmtin Centers fr Disease Cntrl and Preventin Attachment: Summary Cmparisn f Findings
Attachment: Discussin f Cmmunity Water Fluridatin Systemic Reviews: Cchrane Cllabrative, Water Fluridatin t Prevent Tth Decay, 2015 Public Health Service (PHS) Recmmendatin fr Fluride Cncentratin in Drinking Water fr the Preventin f Dental Caries, 2015 (Nte: The 2010 HHS Panel utilized reviews frm the 2013 Cmmunity Preventive Services Task Frce (Task Frce) in the develpment f the 2015 PHS recmmendatin. The Task Frce is an independent, nnfederal, unpaid panel f public health and preventin experts that prvides evidence-based findings and recmmendatins abut cmmunity preventive services, prgrams, and plicies t imprve health. Its members represent a brad range f research, practice, and plicy expertise in cmmunity preventive services, public health, health prmtin, and disease preventin.) Effectiveness f Cmmunity Water Fluridatin: Effectiveness f Water Fluridatin in Reducing Caries in Children: Cchrane fund that water fluridatin is effective in reducing caries in primary and permanent teeth in children. The Cchrane review fund that water fluridatin resulted in fewer teeth affected by cavities (abut 2 primary teeth and 1 permanent tth ), cmpared t cmmunities that did nt have water fluridatin. These differences indicate that initiatin f water fluridatin can result in ntable decreases, up t 35%, in cavities in children. In additin, water fluridatin resulted in higher percentages f children withut any cavities (caries-free). These estimates f fewer teeth affected by cavities in fluridated cmmunities and a higher percentage f caries-free children are similar t findings f ther evidence-based reviews (e.g., the Task Frce in 2013). Fr adlescents, the prevalence f tth decay in the permanent teeth decreased frm 90% in the 1960 s t 60% in recent natinal surveys; the number f teeth affected decreased frm mre than 6 t fewer than 3. Effectiveness f Water Fluridatin in Reducing Caries in Adults: N studies met Cchrane s criteria regarding the effectiveness f water fluridatin in adults. Cchrane includes nly studies where the utcmes are evaluated at tw pints in time in the same sample f adults. Clearly, such an evaluatin ver a lng time perid culd be difficult. Research published in the peer-reviewed literature (in Australia and the United States) fund differences in caries experience (i.e., numbers f teeth r tth surfaces with caries) between adults wh have access t cmmunity water fluridatin and thse wh d nt. Althugh these studies used methds designed t cntrl factrs that might bias findings, they did nt meet criteria established fr the Cchrane review.
These studies pted t cllect data at ne pint in time amng adults with r withut lifetime expsure t fluridatin and then lk back t the time when their permanent teeth wuld have erupted free f tth decay. In these studies, the researchers used statistical methds t cntrl ther factrs, such as age, educatin, and ther fluride expsures, that culd affect the relatinship between fluridatin and tth decay. Findings shw that water fluridatin resulted in lwer caries levels in adults wh were expsed t fluridatin even after ther surces f fluride, such as fluride tthpaste, became widely available. Griffin SO, Regnier E, Griffin PM, Huntley V. Effectiveness f fluride in preventing caries in adults. J Dent Res 2007;86:410-5. Slade GD, Sanders AE, D L, Rberts-Thmpsn K, Spencer AJ. Effects f fluridated drinking water n dental caries in Australian adults. J Dent Res 2013;92:376-82. Strength f the Evidence Supprting Cmmunity Water Fluridatin: While ther reviews, such as that dne by the Task Frce, cncluded that the evidence supprting water fluridatin is strng, Cchrane interpreted this differently. Their selectin criteria excluded mst studies cnducted after 1975, s they fund insufficient evidence t determine if water fluridatin had an impact in an envirnment where fluride prducts such as tthpaste are widely used. There are mre recent peer reviewed, scientifically sund studies dne after 1975 which have fund that water fluridatin is effective in children and adults, but these studies did nt meet Cchrane s criteria fr inclusin. Rugg-Gunn AJ, D L. Effectiveness f water fluridatin in caries preventin. Cmmunity Dent Oral Epidemil 2012;40(Suppl. 2):55-64. Brunelle JA, Carls JP. Recent trends in dental caries in U.S. children and the effect f water fluridatin. J Dent Res 1990;69(Spec Iss):723-727 Griffin SO, Regnier E, Griffin PM, Huntley V. Effectiveness f fluride in preventing caries in adults. J Dent Res 2007;86:410-5. Slade GD, Sanders AE, D L, Rberts-Thmpsn K, Spencer AJ. Effects f fluridated drinking water n dental caries in Australian adults. J Dent Res 2013;92:376-82. Of studies that were included in the review by Cchrane, nly ne the mst recent shwed n effect n severity f tth decay. Cchrane nted in their discussin that this study had a lw level f tth decay at the beginning f the study and the shrtest duratin f fllw-up. Cchrane als nted that the study was cnducted in Australia a cuntry where water fluridatin is widespread. Lw caries levels may reflect the diffusin f fluride frm fluridated t nn-fluridated regins thrugh the cmmercial distributin f prcessed fds and beverages. Impact f Cmmunity Water Fluridatin n Disparate Ppulatins: Cchrane cncluded that there was insufficient infrmatin t shw that fluridatin wrks t reduce differences in tth decay acrss sci-ecnmic grups. Data frm natinal surveys in the U.S. shw that prevalence f tth decay fr grups f adlescents defined by pverty status r race/ethnicity has cntinued t decline ver time. The biggest advantage f cmmunity water fluridatin is that it is the best methd f delivering
fluride t all members f the cmmunity, regardless f age, educatin, incme level r access t rutine dental care. Furthermre, CDC recgnized cmmunity water fluridatin as a majr factr respnsible fr declines in the prevalence and severity f tth decay ver the past 70 years, and named it ne f 10 great public health achievements during the 20th century. Fr example, several studies at the state level have fund that Medicaid csts fr treatment f tth decay were lwer in fluridated than nn-fluridated cmmunities. The difference in annual per child treatment csts ranged frm $28 t $67. Need fr mre Research: Bth the Cchrane Review and the latest review cnducted by the Task Frce identified the need fr mre research t address the effectiveness f fluridatin in the current envirnment f widespread use f fluride tthpaste and ther measures t prevent tth decay, such as fluride varnish and dental sealants. In the U.S., the Centers fr Disease Cntrl and Preventin (CDC) uses data frm the Natinal Health and Nutritin Examinatin Survey (NHANES) t mnitr the ral health f the ppulatin. NHANES began testing hme water samples fr fluride cntent in 2013 and is als asking questins abut use f ther fluride prducts, such as tthpaste and prescriptin fluride drps/tablets, and residence histry. Researchers als will cntinue t examine data fr tth decay as well as dental flursis n a natinal level and fr selected sciecnmic and racial grups.