Outline • Discuss the current evidence on use of fluoride in prevention of the initiation and progression of dental caries
Fluoride • Water fluoridation • Toothpaste and gels (dentifrice) • Additional topical fluoride applications at home: rinses, and high concentration fluoride dentifrices • Professionally applied fluoride applications
FLUORIDE MECHANISMS TO PREVENT CARIOUS LESION PROGRESSION • Remineralization of initial lesions. F, Ca, PO4 Ions from plaque move into demineralized enamel when pH drops. • Interference with bacterial metabolism by inhibiting the enzyme glucosyltransferase. • At high concentrations, F is bactericidal. • May increase the resistance of enamel to acid solubility by pre-eruptive incorporation into the hydroxyapatite crystal. Reference: Journal of Dental Research 1990;69(Spec Issue).
CONCLUSIONS FROM THE STUDY OF HAYES AND COLLEAGUES FROM GRAND RAPIDS STUDY, 1956 • “The decrease in caries appeared to be greater for deeper lesions than for shallow lesions.” • “The decrease in the deeper lesions without a balancing increase in the shallow lesions suggests that fluoride retards the development of caries and that it also prevents the inception of caries.”
Fluoride works best to prevent and control dental caries when a small concentration is constantly present in the oral cavity. The goal of any fluoride program is thus to achieve and maintain this status through frequent exposure to low-concentration fluorides: toothpastes, drinking water, fluoridated salt, rinses, varnishes.
FLUORIDE IN DENTAL PLAQUE • Plays a vital role in remineralization • Plaque usually has 5-10 ppm F (wet weight) • Less than 5% free ions, the rest is bound • Plaque F levels rise with exposure to F; the higher the F content of the exposure, the higher plaque F levels will become • Plaque F levels soon drop without continued introduction of F into the mouth
FLUORIDE IN SALIVA Resting saliva levels are 70% - 80% of plasma F levels. When drinking water is 0.1 ppm F, saliva is 0.006 ppm F When drinking water is 1.2 ppm F, saliva is 0.017 ppm F This difference is considered to be of no clinical importance. Saliva F levels rise exponentially (100- to 1,000- times) when F is introduced into the mouth. Baseline levels return within 3-6 hours.
Fluoridation is the controlled addition of a fluoride compound to a public water supply in order to bring its fluoride concentration up to an optimum level for preventing and controlling dental caries. http://www.cdc.gov/nccdphp/oh/
CARIES IN THE GRAND RAPIDS STUDY 15 y-o 13 y-o 11 y-o 9 y-o Birth Cohort
AGE-STANDARDIZED MEAN DMFT FOR 7-14 y-o CHILDREN IN NEWBURGH (1.0 ppm F) AND KINGSTON (0.1 ppm F) OVER 50 YEARS
FLUORIDATION AND SOCIAL CLASS IN 12-y-o BRITISH CHILDREN. ( Murray et al, 1991). Hartlepool 1.3 ppm F Middlesbrough 0.2 ppm F Newcastle 1.0 ppm F
CARIES EXPERIENCE BY SOCIAL CLASS AMONG BRITISH 5-year-olds IN FLUORIDATED AND NON-FLUORIDATED AREAS: County Durham (Provart and Carmichael 1995). Fluoridated Non-Fluoridated
Water Fluoridation: Current Recommendations • Initial studies of community water fluoridation demonstrated that reductions in childhood dental caries attributable to fluoridation were approximately 50%--60% (94--97). More recent estimates are lower --- 18%--40% (98,99). This decrease in attributable benefit is likely caused by the increasing use of fluoride from other sources, with the widespread use of fluoride toothpaste probably the most important. • The diffusion or "halo" effect of beverages and food processed in fluoridated areas but consumed in nonfluoridated areas also indirectly spreads some benefit of fluoridated water to nonfluoridated communities. This effect lessens the differences in caries experience among communities (100). CDC Recommendations. MMWR 2001
Water Fluoridation: Current Recommendations • Fluoride concentrations in drinking water should be maintained at optimal levels, both to achieve effective caries prevention and because changes in fluoride concentration as low as 0.2 ppm can result in a measurable change in the prevalence and severity of enamel fluorosis . CDC Recommendations. MMWR 2001
Water Fluoridation: University of Your Systematic review • 214 studies were included. The quality ofstudies was low to moderate. Water fluoridation was associatedwith an increased proportion of children without caries and areduction in the number of teeth affected by caries. The range of mean differences in the proportion of children withoutcaries was 5.0% to 64% (14.6%). The range of mean changein decayed, missing, and filled primary/permanent teeth was 0.5to 4.4 (2.25) teeth. A dose-dependent increase in dental fluorosiswas found. BMJ 2000;321:855-859 ( 7 October ). Systematic review of water fluoridation a NHS Centre for Reviews and Dissemination, University of York, York
Fluoridated Dentifrices • Seventy-four studies were included. For the 70 that contributed data for meta-analysis (involving 42,300 children) the D(M)FS pooled PF was 24% (95% confidence interval (CI), 21 to 28%; P < 0.0001). This means that 1.6 children need to brush with a fluoride toothpaste (rather than a non-fluoride toothpaste) to prevent one D(M)FS in populations with caries increment of 2.6 D(M)FS per year. In populations with caries increment of 1.1 D(M)FS per year, 3.7 children will need to use a fluoride toothpaste to avoid one D(M)FS. There was clear heterogeneity, confirmed statistically (P < 0.0001). The effect of fluoride toothpaste increased with higher baseline levels of D(M)FS, higher fluoride concentration, higher frequency of use, and supervised brushing, but was not influenced by exposure to water fluoridation. There is little information concerning the deciduous dentition or adverse effects (fluorosis). Marinho VCC, Higgins JPT, Logan S, Sheiham A. Fluoride toothpastes for preventing dental caries in children and adolescents. Cochrane Database of Systematic Reviews 2003, Issue 1. Art. No.: CD002278. DOI: 10.1002/14651858.CD002278.
Panel Conclusions • Fluoride gel is effective in preventing caries in school-children (Ia). • Patients whose caries risk is low, as defined by the panel, may not receive additional benefit from professional topical fluoride applications (Ia). • Four-minute professionally applied F gels are supported by evidence (Ia); however, there is no clinical equivalency data to support the 1-minute fluoride gel application (IV).
Panel Conclusions • Fluoride varnish applied every six months is effective in preventing caries in the primary and permanent dentitions of children and adolescents (Ia). • Two or more applications of fluoride varnish per year are effective in preventing caries in high-risk populations (Ia).
Panel Conclusions • Fluoride varnish applications take less time, create less patient discomfort and achieve greater patient acceptability than do fluoride gel applications, especially in preschool children (III). • Four-minute fluoride foam applications, every six months, are effective in caries prevention in the primary dentition and newly erupted permanent first molars (Ib). • There is insufficient evidence to address whether or not there is a difference in the efficacy of NaF versus APF gels (IV).
Clinical Recommendations • Caries risk (low, medium, high) • Appropriate preventive dental treatment (including fluoride therapy) can be planned after identification of caries risk status. • Caries risk status should be evaluated periodically. • The panel concluded that there is no single widely accepted risk assessment system. • Dentists, however, can use simple clinical indicators.
High Caries Risk • Younger than 6 years (any of the following) • Any incipient or cavitated primary or secondary carious lesion during the last three years • Presence of multiple factors that may increase caries risk (high titers of cariogenic bacteria, poor oral hygiene, prolonged nursing [bottle or breast]) • Low socioeconomic status • Suboptimal fluoride exposure • Xerostomia (medication-, radiation-, or disease-induced)
Clinical Recommendations • High-caries risk • < 6 years • Varnish application at 6-month intervals (A) • Varnish application at 3-month intervals (D) • 6 to <18 years • Varnish or gel applications at 6 month intervals (A) • Varnish application at 3-month intervals (A) • Gel application at 3-month intervals (D) • 18 years • Varnish or gel applications at 3- or 6-month intervals (D)
Clinical Recommendations • Low-caries risk • < 6 years and 6-18 years • May not receive additional benefit from professional topical fluoride application (B) (Fluoridated water and dentifrices may provide adequate prevention) • 18+ years • May not receive additional benefit from professional topical fluoride application (D)
Other Considerations • The available evidence on fluoride foam is weak and the Panel did not make a recommendation. • Application time for fluoride gel and foam should be four minutes.
ADA Clinical Recommendation on Sealants
ADA Clinical Recommendations • Pit and fissure sealants can be used effectively as part of a comprehensive approach for caries prevention on an individual basis or as a public health measure for at-risk populations.
ADA Clinical Recommendations • Sealants are placed to prevent caries initiation and to arrest caries progression by providing a physical barrier that inhibits micro-organisms and food particles from collecting in pit and fissure surfaces.
ADA Clinical Recommendations • It is generally accepted that the effectiveness of sealants for caries prevention is dependent on long-term retention. • Full retention of sealants can be evaluated through visual and tactile exams. In situations where a sealant has been lost or partially retained, the sealant should be reapplied to ensure effectiveness.
ADA Clinical Recommendations • Pitandfissuresealantsarecurrentlyunderutilized,particularlyamongthoseathighriskforcaries,includingchildreninlowerincomeandcertainracialandethnicgroups. • Thenationaloralhealthobjectivesfordentalsealants,asstatedintheUSDepartmentofHealthandHumanServicesinitiativeHealthyPeople2010,includesincreasingtheproportionofchildrenwhohavereceiveddentalsealantsontheirmolarteethto50percent.
ADA Clinical Recommendations • US national data indicate that sealant prevalence on permanent teeth among children aged 6 to 11 years is 30.5 percent but represents a substantial increase over the 8 percent prevalence reported in 1986-87.
ADA Clinical Recommendations • Placement of resin-based sealants on the permanent molars of children and adolescents is effective for caries reduction. Ia • Reduction of caries incidence after placement of resin-based sealants ranges from 86 percent at one year, to 78.6 at two years, and 58.6 percent at four years in children and adolescents. Ia
ADA Clinical Recommendations • Sealants are effective in reducing occlusal caries incidence in permanent first molars of children, with caries reductions of 76.3 percent at four years when sealants were reapplied as needed. • Caries reduction was 65 percent at nine years from initial treatment, with no reapplication during the last five years. Ib
ADA Clinical Recommendations • Pit and fissure sealants are retained on primary molars at a rate of 74.0 to 96.3 percent at one year, 59 and 75 percent at 2.8 years. III • There is consistent evidence from private dental insurance and Medicaid databases that placement of sealants on first and second permanent molars in children and adolescents is associated with reductions in the subsequent provision of restorative services. III
ADA Clinical Recommendations • Placement of pit-and-fissure sealants significantly reduces the percentage of non-cavitated carious lesions that progress in children, adolescents and young adults up to five years after sealant placement, compared with unsealed teeth. Ia
ADA Clinical Recommendations • Sealants should be placed in children on pits and fissures of primary teeth when it is determined that the tooth, or the individual, is at risk for caries. III, D • Sealants should be placed in children and adolescents on pits and fissures of permanent teeth when it is determined that the tooth, or the individual, is at risk for caries. Ia, B • Sealants should be placed in adults on pits and fissures of permanent teeth when it is determined that the tooth, or the individual, is at risk for caries. Ia, D
ADA Clinical Recommendations • Pit and fissure sealants should be placed on early (non-cavitated) carious lesions … in children, adolescents and young adults, to reduce the percentage of lesions that progress. Ia, B • Pit and fissure sealants should be placed on early (non-cavitated) carious lesions, as defined in this document, in adults, to reduce the percentage of lesions that progress. Ia, D
ADA Clinical Recommendations • Resin-based sealants are the first choice of material for dental sealants. Ia, A • Glass ionomer cement may be used as an interim preventive agent when there are indications for placement of a resin-based sealant but concerns about moisture control may compromise the placement of a resin-based sealant. IV, D
ADA Clinical Recommendations • A compatible one-bottle bonding agent, which contains both an adhesive and a primer, between the previously acid-etched enamel surface and the sealant material may be used when, in the opinion of the dental professional, retention may be enhanced in the clinical situation. Ib, B • Presently available self-etching bonding agents, which do not involve a separate etching step, may provide less retention than the standard acid etching technique and are not recommended. Ib, B
ADA Clinical Recommendations • Routine mechanical preparation of enamel before acid etching is not recommended. IIb, B • Use a four-handed technique while placing resin-based sealants, when possible. III, C • Use a four-handed technique while placing glass ionomer cement sealants, when possible. IV, D • Monitor and reapply sealants as needed to maximize effectiveness. IV, D
Sealants: Conclusions • Sealants are effective as primary and secondary preventive materials. • Sealants should be applied to at-risk teeth within an integrated oral health promotion and prevention program. • Sealants require re-evaluation on a regular basis. • Sealants should be part of a comprehensive oral health promotion and prevention program that provides dental care.