Prevention of Dental Caries

1
Prevention of Dental Caries
2
Outline

• Discuss the current evidence on use of fluoride
  in prevention of the initiation and progression
  of dental caries

3
Fluoride

• Water fluoridation
• Toothpaste and gels (dentifrice)
• Additional topical fluoride applications at home
  rinses, and high concentration fluoride
  dentifrices
• Professionally applied fluoride applications

4
Mechanisms of Action
5
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
  199069(Spec Issue).

6
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.

7
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.
8
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

9
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.
10
Water Fluoridation
11
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/
12
CARIES IN THE GRAND RAPIDS STUDY
15 y-o
13 y-o
11 y-o
9 y-o
Birth Cohort
13
CARIES IN BRITISH CHILDREN AGED 12 WHEN
FLUORIDATION STARTED
27 Less
14
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
15
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
16
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
17
FLUOROSIS IN DEANS STUDIES IN THE 1930s
18
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
19
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
20
Water Fluoridation University of Your Systematic
review

• 214 studies were included. The quality of studies
  was low to moderate. Water fluoridation was
  associated with an increased proportion of
  children without caries and a reduction in the
  number of teeth affected by caries. The range of
  mean differences in the proportion of children
  without caries was 5.0 to 64 (14.6). The range
  of mean change in decayed, missing, and filled
  primary/permanent teeth was 0.5 to 4.4 (2.25)
  teeth. A dose-dependent increase in dental
  fluorosis was found.

BMJ 2000321855-859 ( 7 October ). Systematic
review of water fluoridation a NHS Centre for
Reviews and Dissemination, University of York,
York
21
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 lt 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 lt 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.
22
Professionally Applied Topical Fluorides
23
Grade Category of Evidence
Ia Evidence from systematic reviews of randomized controlled trials
Ib Evidence from at least one randomized controlled trial
IIa Evidence from at least one controlled study without randomization
IIb Evidence from at least one other type of quasi-experimental study
III Evidence from non-experimental descriptive studies, as comparative studies, correlation studies, cohort studies and case-control studies
IV Evidence from expert committee reports or opinions or clinical experience of respected authorities
24
Classification Strength of Recommendations
A Directly based on category I evidence
B Directly based on category II evidence or extrapolated recommendation from category I evidence
C Directly based on category III evidence or extrapolated recommendation from category I or II evidence
D Directly based on category IV evidence or extrapolated recommendation from category I, III or III evidence
25
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).

26
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).

27
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).

28
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.

29
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)

30
Clinical Recommendations

• High-caries risk
• lt 6 years
• Varnish application at 6-month intervals (A)
• Varnish application at 3-month intervals (D)
• 6 to lt18 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)

31
Clinical Recommendations

• Low-caries risk
• lt 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)

32
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.

33

• ADA
• Clinical Recommendation on Sealants

34
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.

35
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.

36
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.

37
ADA Clinical Recommendations

• Pit and fissure sealants are currently
  underutilized, particularly among those at high
  risk for caries, including children in lower
  income and certain racial and ethnic groups.
• The national oral health objectives for dental
  sealants, as stated in the US Department of
  Health and Human Services initiative Healthy
  People 2010, includes increasing the proportion
  of children who have received dental sealants on
  their molar teeth to 50 percent.

38
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.

39
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

40
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

41
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

42
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

43
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

44
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

45
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

46
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

47
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

48
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.