Preventive Dentistry

(Lecture 10)

Other caries preventive factors

Dr Caroline Mohamed

D Caroline Mohamed 1

Outline of lectures

OTHER CARIES-PREVENTIVE FACTORS Fluorides Topically applied fluoride Systemically administered fluoride Fluorides agents and compounds for topical use Delivery systems for topical self-application of fluoride Other oral hygiene aids Delivery systems for professional topical application of fluorides

D Caroline Mohamed 2

Topical Applied Fluoride

• The posteruptive cariostatic effects of fluoride are correlated with : –

fluoride concentration

as well as with –

total exposure time

.

The latter is also influenced by the

fluoride in the oral cavity.

"substantivity

" of D Caroline Mohamed 3

• • •

Fluoride clearance fases.

First

within 1 hour.

The analysis of saliva after a single application of a dentifrice or mouthwash fluoride shows that much of the retained fluoride is

cleared from the mouth within 1 hour.

• • •

Secondary

clearance phase of 2 hours or more .

The salivary fluoride concentration decreases more slowly.

The initial rapid clearance phase

is the result of

salivary washout

and the

second phase

is initiated by the

release into saliva of fluoride initially retained in oral reservoirs.

(Duckworth et al, 1991, 1994) D Caroline Mohamed 4

Potential reservoirs are:

– the teeth, – the plaque, – the soft tissues of the gingiva, – the tongue, – the cheeks, and – stagnation zones between the teeth, under the tongue, and in the buccal sulcus. D Caroline Mohamed 5

•

From a cariostatic aspect

, the

most important fluoride reservoirs

are: –

CaF 2 and

–

fluoride bound to plaque bacteria.

D Caroline Mohamed 6

• • The

most important effects of posteruptive

(

topical

) use of fluoride are: – –

the inhibition of demineralization and enhancement of remineralization.

Fluoride exerts

physiochemical effects

i n: –

the oral fluids, such as the interrod and intercrystalline fluid, pellicle fluid, plaque fluid, and saliva,

–

bound in CaF 2 , FA, and FHA

( fluorohydroxyapatite).

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• • •

Fluoride also: reduces acid formation in the dental plaque, may reduce plaque formation rate and plaque adhesion, and may change the ecology of the plaque microflora. Of these effects, the most important is the reduction of acid formation.

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• • • The fall in plaque pH following sucrose plaque fluoride content has been exposure is reduced when

enhanced by repeated topical treatment

.

Fluoride alone is inadequate to completely arrest caries

because its cariostatic effect is limited.

process If plaque

pH falls below about 4.5

, the plaque fluid becomes

undersaturated

with respect to

fluorapatite, and demineralization will occur

, regardless of the presence of fluoride.

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Systemically administered fluoride

• • The cariostatic effect of fluoride is posteruptive (

topical effect

).

almost

100% Fluoride has been systemically administered in:

drinking water, salt, milk, tablets, lozenges, chewing gums, drops.

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• • • Different concentrations of in these delivery systems.

sodium fluoride

have been used

Fluoridated drinking water is the most cost-effective public health measure for prevention and control of caries and remineralization of early enamel caries.

This is due to the fact that most people drink water several times a day with even those without regular dental care and regular use of fluoride toothpaste benefit from water fluoridation.

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• •

Water fluoridation should therefore be recommended in all populations in which there is a relatively high caries prevalence, poor oral hygiene, and a lack of organized preventive programs or daily use of fluoride toothpaste.

The recommended fluoride concentration in is 0.7 to 1.2 mg of F/L , but in temperate climates, warm to hot subtropical and tropical regions, only 0.5 to 0.7 mg of F/L is recommended, to prevent the development of esthetically unacceptable fluorosis.

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•

Results from early studies with fluoridated water showed about 50% caries reduction in the permanent dentition and 40% in the primary dentition, compared to control areas. Significant reductions in root caries were also seen (Murray et al 1991).

• •

At that and in time, caries prevalence was high in the United States Europe , where the studies were run, and few topical agents such as toothpaste and mouthrinses were available.

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•

Nowadays , the supplementary effect of fluoridated drinking water would be only 5% to 25% in most European countries and the USA , because of improved oral hygiene and daily use of fluoride toothpaste and other topical fluoride agents , red uctions which have resulted in in both caries very significant prevalence and incidence .

•

However, in regions with relatively high caries prevalence, limited dental resources, and no daily use of fluoride toothpaste, water fluoridation should still achieve about 50% caries reduction.

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•

However, only about 3% of the world population has access to fluoridated drinking water , mostly in the USA, where caries prevalence is low and almost 100% of the population use fluoride toothpaste and other topical fluoride agents daily.

•

The use of the other fluoride delivery systems in the world is marginal (salt, 0.6%; tablets, etc 0.3%).

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Prevalence of dental fluorosis

• • •

an increase in the prevalence of dental fluorosis has been noticed.

The increase is in the mild and very mild forms of fluorosis, and is proportionally greater in non fluoridated areas than in fluoridated areas.

This is because of the increase in the mean fluoride intake from all sources since the 1940s.

Some of the reasons that were postulated for the increase in the prevalence of fluorosis

•

widespread fluoridated communities.

use of and fluoride in both non-fluoridated

•

Foods and beverages may be processed in fluoridated communities but are shipped, sold, and consumed in non-fluoridated communities.

•

Hallo effect

Worldwide distribution

• • • •

Endemic in 22 countries

in Asia, India and China are worst affected Mexico in North and Argentina in Latin America

East and North Africa are also endemic

Risk factors

• • • • The most important risk factor in determining fluorosis occurrence and severity is the

total amount of fluoride consumed from all sources during the critical period of tooth development. Demographic risk factors: Age: fluorosis is related to the ingestion of F during critical period of tooth development.

SES : fluoride intake from tooth paste and infant formula can vary by SES status

Optimal levels of fluoride drinking wat

er

• • • It was accepted that optimal level of fluoride in drinking water was 1PPM.

With other sources of fluoride now days this level become 0.5 to 1 ppm according to the community.

Waters with high levels of fluoride content are mostly found at the foot of high mountains and in areas where the sea has made geological deposits.

• • • •

Known fluoride belts on land include:

one that stretches from Syria through Jordan, Egypt,

Libya

, Algeria, Sudan and Kenya, and another that stretches from Turkey through Iraq, Iran, Afghanistan, India, northern Thailand and China.

There are similar belts in the Americas and Japan.

In these areas fluorosis has been reported.

Fluoride dietary supplement

• • • Was used in non fluoridated areas There is strong evidence that fluoride supplements are risk factor to mild to moderate fluorosis.

The risk is high in fluoridated areas.

Early use of fluoride tooth paste

• • Young children in whom the swallowing reflex is not fully developed can ingest up to 0.3 –o,5mg F at each brushing.

The risk is not as high as fluoride supplement

• • Infant formula: B/C its own F content and especially because it is mixed with fluoridated water.

Other factors that have been associated with susceptibility of populations to dental fluorosis are altitude, renal insufficiency, and possibly malnutrition.

Dietary supplements

• • •

Fluoride dietary supplements were first introduced in the late 40´s and were intended as a substitute for fluoridated water for children in non-fluoridated areas.

S upplements contain fluoride from 0.25 , 0.5 to 1.0 mg usually as sodium fluoride or calcium fluoride, acidulated phosphate fluoride or potassium fluoride.

The original pills have been joined by lozenges.

chewable tablets and

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• • • Animals experiments shown that fluoride given once a day is more likely to cause fluoroses than the same ammount of fluoride given intermittently.

In Europe, it is recommended that a dose of 0.5 mg F/day should be prescribed

only to children living in areas with water supplies containing less than 0.3 ppm F, who are considered to be high risk , after a diet analyses, starting only at age of 3 years.

THE FLUORIDE SUPPLEMENT HAS NO PLACE IN PUBLIC HEALTH

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American Dental Association. Fluoride and fluoridation. Available at: www.ada.org/public/topics/fluoride. Accessed June 20, 2007.

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• • •

The aim of using fluoride tablets is to achieve a supplementary posteruptive cariostatic effect similar to that provided by other topical fluoride agents, such as toothpaste.

Therefore , slow release lozenges should be recommended because of the prolonged fluoride clearance time in the oral fluids.

An optimal effect should be achieved if the lozenges are used as a "dessert" directly after meals, particularly in adults with reduced salivary secretion rates.

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• •

For very caries-susceptible patients fluoride chewing gum should be the preferred systemic agent, to be used for 15 minutes directly after every meal.

It is recommended primarily for caries-susceptible adults with reduced salivary secretion rates and for caries susceptible children and young adults, especially during the eruption of molars (5.5 to 7 years and 11.5 to 13 years).

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Fluoride agents and compounds for topical use

• • • •

The caries-preventive effect of most topical fluoride measures to range between 20% and 40%.

Topical fluoride agents are available for

professional application selfcare

or (eg, by dentists, dental hygienist or dental assistant).

For

selfcare

, the fluoride agents can be used:

toothpastes; toothpicks, dental tape, and dental floss; mouthrinses; gels, artificial saliva, lozenges, and chewing gum.

Professionally

applied fluoride agents are

paints; gels; prophylaxis pastes; varnish, glass-ionomer cement (GC), and other slow release agents.

D Caroline Mohamed 31

Toothpastes

The cariostatic effect of fluoride toothpastes was recognized more than 40 years ago.

More than 90% of toothpastes in the industrialized countries contain fluoride (WHO 1994).

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• •

Fluoride toothpaste is by far the most frequently used topical fluoride agent, used by 450 million people (WHO 1994).

Only 20 million people use mouthrinses or tablets, while 20 million receive professional applications of fluoride (WHO 1994).

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The main functions of toothpastes are to

facilitate mechanical plaque removal by brushing and to serve as vehicles for active agents

(

fluorides, chemical plaque control agents, anticalculus agents, etc.).

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D Caroline Mohamed 35

Fluoride

 

The use of fluoride dentifrices has reduced the incidence of caries by 9.7% – 24.9% 1 Sodium fluoride (NaF) and sodiummonofluorophosphat e (MFP) are the most common sources of fluoride in dentifrices

– These can be used alone

or in combination

1. Twetman S, et al. Acta Odontologica Scandinavica 2003;61;6:347-355.

2. Volpe AR, et al. Am J Dent. 1993;6:S13-S42.

3. Sullivan RJ, et al. J Clin Dent. 1995;6:135-138.

Fluoride formulation factors and mode of action

 Not all fluoride toothpastes are the same –

Different fluoride source, pH and choice of formulation can affect fluoride uptake 1,2



Fluoride needs to be deposited and slowly released to be effective following brushing 3

–

The amount of fluoride released into saliva and adsorbed by enamel during the period after brushing is critical

1. Friberger P. Scand J Dent Res 1975:83;339-344.

2. White DJ, et al. Caries Res 1986;20:332-336.

3. ten Cate JM. Eur J Oral Sci 1997;105:461-465.

Many different fluoride compounds are used in agents for self-care and professional application. The three main categories are:

1

. Inorganic compound s

, including NaF, stannous fluoride (SnF 2 ), ammonium fluoride (NH 4 F ) etc. The salts are readily soluble, providing free fluoride.

2.

Monofluorophosphate-containing compounds

, such as sodium monofluorophosphate (Na 2 FPO 4 ): The fluoride is covalently bound in the FPO 3 2 ion and apparently requires hydrolysis to free the F .

3.

Organic fluorides ,

such as amine fluoride, and silane fluorides.

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Ionic compounds

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Factors that influence fluoride delivery

  

Fluoride sour

ce (NaF, MFP, stannous fluoride) – For example, MFP requires activation by hydrolysis by salivary phosphatase to release active F -

Fluoride concentration in formulation Formulation properties

– pH will drive different fluoride modes of action – Ingredients such as divalent cations (eg, Ca 2+ ) can reduce the amount of available fluoride – Ingredients such as high levels of phosphates can reduce fluoride uptake

Sometimes two or more of the above compounds are combined in the same topical fluoride agent.

The fluoride concentration in agents for self-care, such as toothpastes and mouthrinses, varies from fluoride , while up to 1 % fluoride is used 0.012% to 0.15% in gels.

The fluoride concentration in agents for professional application to 6.0%, is usually much higher, ranging from about which, as discussed earlier, will promote

precipitation of

CaF 2 reservoirs

.

0.7%

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Fluorides mouthwashes

• • • •

Stannous Fluoride- antiplaque properties Sodium Fluoride

The stannous ion, not the fluoride, which is responsible for antimicrobial effect.

Mechanism of action:

Tin from the stannous ion enters the cell, impairs the metabolism and effect the growth and adherence properties of bacteria.

Week antiplaque activity .

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Delivery systems for topical self-application of fluorides

The following topical fluoride agents are available for self-care: toothpastes; toothpicks, dental floss, and dental tape; mouth rinses; gels; artificial saliva; lozenges; and chewing gum. D Caroline Mohamed 43

The following fluoride compounds are used in toothpastes:

l. Inorganic fluorides

a. Sodium fluoride (NaF) b. Sodium monofluorophosphate (Na 2 FPO 3 ) c.

Stannous fluoride (SnF 2 ) d. Potassium fluoride (KF) e. Aluminum fluoride (AlF 3 ) D Caroline Mohamed 44

2. Organic fluorides

a. Amine fluoride (Hetaflur) b. Amine fluoride (Olaflur)

3. Combinations of fluorides

a. Sodium fluoride + sodium monofluorophosphate b. Amine fluoride + Stannous fluoride c. Amine fluoride + Sodium fluoride D Caroline Mohamed 45

• • • Sodium fluoride and sodium monofluorophosphate are by far the most common, followed by stannous fluoride and amine fluoride .

Almost all the

NaF, SnF 2 ,

and

amine fluoride in toothpastes will be dissolved in the mouth during brushing, releasing optimal amounts of free F ions.

On the other hand

free F Na 2 FPO 3

initially

releases fewer ions, but also supplies FPO 3 2 ions which within about 1 hour are broken by phosphate enzymes in the mouth, releasing F ions

.

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• From 1955 to 1985 the standard fluoride concentration in toothpastes was about

1,000 ppm of fluoride (0.1% F=1 mg F/g

toothpaste), supplied as 0.2% Na F, 0.76% Na 2 FPO 3 , SMFP and 0.4% SnF 2 .

• The average

caries reduction

achieved in various

2- to 3-year clinical studies was about 25% to 30 %

(Johnson,1993; Volpe et al, 1993).

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• The cariostatic elfects of fluoride toothpastes are also related to accessibility and fluoride clearance in the oral fluids.

• Accessibility may be improved by:

1. Frequent mechanical removal of dental plaque, particularly on the approximal surfaces of the posterior teeth.

2. Deliberate application of fluoride toothpaste to the posterior interdental spaces before approximal cleaning.

3. Thorough swishing with the remaining toothpaste slurry after cleaning, followed only by one brief rinse with water.

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The following measures may prolong fluoride clearance time from the oral fluids: 1. Using as high a fluoride concentration as possible.

2. Increasing the daily frequency of fluoride toothpaste.

3. Using the toothpaste technique recommended above

.

4. Filling the posterior interdental spaces with fluoride toothpaste after cleaning at bedtime.

D Caroline Mohamed 49

• Toothpastes containing

fluoride as well as chemical plaque control agents should be recommended, particularly to caries-susceptible patients with high plaque formation rates

(Plaque Formation Rate Index score 4 to 5,

gingivitis. ) periodontitis, or Toothpastes containing SnF 2 or amine fluoride also have documented antiplaque effects.

D Caroline Mohamed 50

Other oral hygiene aids

•

Oral hygiene aids that not only mechanically remove plaque but also at the same time, release fluoride to the most caries susceptible tooth surfaces in the dentition, the approximal surfaces of the posterior teeth, would be most appropriate.

•

Several brands of fluoridated toothpicks (TePe, Butler, Elmex, Jordan, etc) and dental tape and floss (Johnson & Johnson, Oral B, Butler, Elmex,J ordan, etc) have been introduced commercially.

D Caroline Mohamed 51

Mouthrinses

Weekly school-based mouthrinsing with

10-mL neutral 0.2% NaF solutions for 1 minute

are still

very cost effective for caries control

in regions where water fluoride concentration is low, for

populations with high prevalence of caries, poor oral hygiene and no daily use of fluoride toothpaste.

D Caroline Mohamed 52

• •

Rinsing with 10 ml of fluoride solution (0.025% F) for 1 minute after every tooth cleaning procedure is an efficient supplement for caries control in caries-susceptible patients.

Fluoride mouthrinses containing chemical plaque control agents ( triclosan + copolymer+ sodium lauryl sulfate solutions.

[Colgate Total], chlorhexidine, amine fluoride + SnF 2 [Meridol], etc) should have a greater cariostatic effect than pure neutral NaF

D Caroline Mohamed 53

Artificial saliva

For patients with dry mouth (xerostomia), artificial saliva containing NaF is available to improve physical and subjective symptoms and reduce the risk of rampant caries in these extremely high-risk patients.

However, in these patients, meticulous mechanical and chemical plaque control and combination of the m ost efficient fluoride agents are also essential.

Fluoridated artificial spray is formulated either as a gel or as a spray; patient acceptance is generally higher for the spray, which is usually applied 20 to 30 times a day.

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The effect of fluoride gels is related to the of application, accessibility,

Gels

concentration, time and other factors.

Most commercial fluoride gels for daily use by self-care contain about 0.5% fluoride in the form of neutral NaF, acidulated phosphate fluoride, SnF 2 or amine fluoride plus NaF.

two also have documented anti plaque effects.

The last

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Gels

• To improve the effect of the gels, the recommended application time is 4 minutes or more preferably applied in customized trays.

D Caroline Mohamed 57

Delivery systems for professional topical application of fluorides

• • • The following systems are available for professional application:

fluoride solutions for painting gels, prophylaxis pastes, and slow-release agents, such as varnishes and glass-ionomer cements.

The fluoride concentration in agents for professional use ranges from 1% to 8%. D Caroline Mohamed 58

The fluoride compounds most commonly used professionally are neutral

NaF, acidulated phoshate fluoride,and SnF

2

.

Amine fluoride and silane fluoride are also in some commercial products.

For optimal accessibility, plaque must be removed by professional mechanical tooth cleaning before the fluoride agent is applied to the tooth surfaces at greatest risk.

D Caroline Mohamed 59

Professionally applied fluoride agents recommended for public health programs for.

are

1. for areas with relatively homogenous

high-risk prevalence, fluoride-deficient drinking water and lack of fluoride toothpaste,

but personnel resources available for a

school-based preventive program;

2. in

special risk groups

such as the

mentally handicapped or elderly people with reduced salivary flow, exposed root surfaces and heavily restored dentitions; and in people with senile dementia.

D Caroline Mohamed 60

From a

cost-effectiveness

aspect professionally applied fluoride agents are also justified as a public health measure for specific groups of children,

during eruption of the first and second molars (5 to 7 year olds and 11 to 13 year olds).

D Caroline Mohamed 61

Fluoride solutions for painting

The most common fluoride solutions for painting are neutral 2% NaF (1% F), 8% SnF 2 (2% F) and acidulated phosphate fluoride (1.23% F).

D Caroline Mohamed 62

Fluoride gels

Fluoride gels for professional use contain a similar assortment of fluoride compounds as gels for self-care ( neutral NaF, acidulated phosphate fluoride, SnF2, amine fluoride plus NaF).

For optimal accessibility, plaque must he removed by professionally by mechanical tooth cleaning, the gel syringed into the posterior interproximal spaces, followed by gel application in a customized tray for more than 4 minutes.

D Caroline Mohamed 63

Fluoride gel in disposable trays

D Caroline Mohamed 64

Prophylaxis pastes

• They are used mainly for professional mechanical tooth cleaning but also for finishing and polishing and may contain fluoride. D Caroline Mohamed 65

Semislow-release and slow-release fluoride agents

• • These are such as

cements.

fluoride varnishes, glassionomer

Examples of

fluoride varnishes

are:

Duraphat

(5% NaF; 2.3% F), fluoride; 0.1% F) and

Bifluorid

about 6% F).

Fluor Protector (silan 12 (6% NaF + 6% CaF 2 ; Based on clinical studies, the

caries reduction achieved by fluoride varnishes ranges from 20% to 70%.

D Caroline Mohamed 66

Fluoride varnish

D Caroline Mohamed 67

• • It is recommended that the initial varnish application be repeated

3 times within 7-10 days in patients with caries risk

, to

heal gingivitis,

thereby reducing the plaque formation rate, and to

arrest enamel

caries by

micropore surface as soon as possible.

sealing the outer

Thereafter the varnish should be reapplied

intervals, 2-4 times/year.

at needs related

D Caroline Mohamed 68

Activity

• Detail the techniques for fluoride gel application and fluoride varnish application and their indications.

D Caroline Mohamed 69

Thanks It is not fun!

D Caroline Mohamed 70