Preventive and Bleaching Materials Chapter 7. Fluorides Naturally occurring Have proved very...

Preventive and Bleaching Materials

Chapter 7

Fluorides

Naturally occurringHave proved very effective and safe in

preventing dental decayOne of the greatest public health

successes of the 20th centuryMay occur naturally or by supplementAccepted optimal level of fluoride in

drinking water is 0.7 to 1.2mg/L or parts per million (ppm)

Too Much Fluoride

Dental fluorosis, also known as mottled enamel, may appear as white spots (mild) to large brown spots and badly weakened enamel in severe cases.

Eating fluoridated toothpaste or swallowing supplemental fluoride during dental treatment can cause fluorosis.

Community FluorideFluorine, from which fluoride is derived, is

the 13th most abundant element and is released into the environment naturally in both water and air.

Fluoride is naturally present in all water.Community water fluoridation is the

addition of fluoride to adjust the natural fluoride concentration of a community’s water supply to the level recommended for optimal dental health, that is, approximately 1.0 ppm (parts per million).

Systemic and Topical Fluorides

Systemic fluorides are also known as dietary fluorides.

They are ingested in food and water, other beverages, and supplements.

The required amount of fluoride is absorbed through the intestine into the bloodstream.

Topical fluorides are non-dietary and are applied directly to the teeth.

Topical Fluorides

Professional application, usually by the hygienist, in the dental office

Applied by gel or foam for 4 minutesToothpastes containing fluoride are

important for daily use.

Copyright © 2011 by Saunders, an imprint of Elsevier Inc.

Topical vs. Systemic

For years it has been thought that fluoride incorporated into the teeth at the time of development was the main reason for the lowering of dental caries (tooth decay) rates seen in areas of water fluoridation

Studies show that fluoride’s greatest anti-caries benefit is gained from topical fluoride exposure after the teeth have erupted

Fl makes it more difficult for the acids produced by cariogenic (decay causing) bacteria in plaque to demineralize tooth structure and cause dental caries

There is evidence that fl from drinking water, toothpastes, mouth rinses, and some foods remain in the saliva for hours and has a prolonged topical effect


Protection Against Erosion

Highly acidic foods and beverages such as citrus fruits, sodas, and wine can contribute to the loss of tooth mineral that is called erosion

Erosion differs from caries because bacteria are not involved and most of the mineral is lost at the tooth surface

Some medical conditions also cause erosion of the teeth by causing stomach acid to enter the mouth (acid reflux, bulimia, anorexia

By making the tooth structure less soluble in acids, fluoride provides some degree of protection against erosion, but repeated acid attacks will overcome the beneficial effects of fluoride


Bacterial Inhibition

Fluoride interferes with the essential enzyme activity of the bacteria

Although fluoride ions have not been shown to cross the bacterial cell wall, it can travel through in the form of hydrofluoric acid (HF)

The HF separates into the fluoride ion and the hydrogen ion and disrupts the enzyme activities essential to the functioning of the bacteria and cause their death


Fluoride and Antibacterial Rinses for Caries Control

Fl alone is not as effective in managing dental caries as when it is used in conjunction with an antibacterial mouth rinse

Chlorhexidine gluconate is effective against a broad spectrum of microorganismss

In the US the maximum concentration is 0.12% Most effective against the reduction of plaque (55%) and

gingivitis (45%) Antibacterial effect from a single dose is greatest for several

hours after use, but may last for a few days Used in the management of bacteria associated with perio

and is also effective in suppressing mutans-type Streptococci associated with dental caries


Method of Delivery Dietary Fluoride Supplements

Not desired when the community water supply fl content is higher than 0.6 ppm

In-Office Fluoride Applications (Topical) Self-Applied Topical Gels

Recommended for moderate to high risk for dental caries

Self-applied gels are available by prescription as 1.1% neutral sodium fluoride (5000 ppm fluoride) or 0.4% stannous fluoride (900 ppm fluoride)

Not recommended for children younger than 6 years Over-the-Counter Fluoride Rinses

Rinses available are 0.05% sodium Fl (225 ppm) Gel-Kam, ACT, Prevident

Fluoride-Containing Toothpaste Fl content of most paste is 1000 ppm

Fluoride-Containing Prophylaxis Pastes Most common additive 1.23% APF


Safety

Most common reaction seen in the dental office or shortly after leaving the office when a child has swallowed fluoride is nausea and vomiting

Pit and Fissure Sealants

Sealants are unfilled or lightly filled resins that are used to seal the noncarious pits and fissures of deciduous and permanent teeth.

The purpose of the sealant is to prevent dental caries in the pits and fissures found primarily on the occlusal surfaces of posterior teeth.

Pit and Fissure Sealants (cont’d)

The widespread use of fluoride has caused a dramatic reduction in dental caries in children.

The greatest benefit derived from fluorides has been the smooth surfaces of teeth.

Most incidents of caries in children (approximately 88%) occur in the pits and fissures.


The pits and fissures are often deep, narrow, and impossible to reach with the bristles of a toothbrush.

These areas then collect food, debris, and bacteria, which begins the demineralization process.


Sealants provide a conservative means of protecting pits and fissures by preventing debris, food, and bacteria from settling in these areas.

When a sealant is placed early, before cavitation has begun, it provides an effective barrier.


If caries are sealed over, typically the caries process is stopped, because a food source is no longer available to continue the process.

If the sealant is poorly placed, the margins could leak and the caries process could continue.

Indications

Not all teeth need sealants.Teeth indicated for sealants are those

with deep pits and fissures.Teeth with uncoalesced grooves are at

greatest risk for caries.

Composition

Sealants are chemically similar to composite resin.

Their resin component is based on a dimethacrylate monomer (bis-GMA).

Polymerization of the resin occurs by chemical reaction or by light activation.

Working Time

The self-cured sealant polymerizes to final set within approximately 2 minutes from the start of mixing of the two components.

When the material is light-cured, the operator can manipulate the material at will.

The light-cured material requires a 20-second application of the curing light to each tooth or surface to which the material is applied.

Color and WearManufacturers provide sealants in a

variety of colors.Sealant may be clear, amber, or

opaque.The clear material is very difficult for

the dentist to see once placed.Sealants are checked at each exam for

determination of stability.

Color and Wear (cont’d)Sealants are subject to wear on the

occlusal surface.Unfilled sealants wear faster than

filled sealants.Wear typically is not an issue if the

sealant is placed properly.


Sealants Cont’d

Studies had shown that etched enamel begins remineralization after a 24-hour exposure to saliva by deposition of calcium phosphate salts

In areas where sealants wear away, resin tags remaining in the enamel provide some caries protection

See Table 7-3 for potential problems and ways to solve the problems

Desensitizing Agents

Many patients experience sensitivity in their teeth to cold foods or beverages, sweets, or cold air.

Desensitizing agents are used to reduce or eliminate the problem.

Some agents are available over the counter.

Others can be applied in the dental office.

Causes of Tooth SensitivityTeeth may become sensitive when

dentinal tubules are exposed to the oral cavity.

Stimulus fluid enters the tubules and can irritate the pulp.

Temperature, sugars, and acids are the biggest causes of sensitivity.

Another cause is exposed root structure (cementum).

TB abrasion, erosion, abfraction and SRP are also contributing factors for exposed dentin

Treatment

Many desensitizing agents work by closing the open ends of the dentinal tubules.

This process can be chemical or mechanical.

Some desensitizing agents use potassium nitrate to directly affect pulp sensitivity.

Treatment (cont’d)

Desensitizing agents are used in several different ways to decrease or eliminate sensitivity.

These include the following: Under a restoration After a routine cleaning In areas of gingival recession On exposed root surfaces

Treatment (cont’d)

The duration of relief may vary from days to weeks to up to a year.

The way to best eliminate sensitivity is to eliminate the source of the problem: Brushing technique Restoration Acidic diet Temperature change

Mouth Guards and Splints

The purpose of mouth guards and splints is to protect the teeth and their supporting structures.

Mouth guards are recommended for Athletics (not just contact sports)

Many states mandate use of mouth guards Use as night guards

Sports Mouth GuardsMouth guards for sports can be

purchased in any sports store.Stock mouth guards are available in a

variety of sizes and typically do not fit very well: Thick and bulky Poor fit

Sports Mouth Guards (cont’d)

Ideally, a good mouth guard is custom made in the dental office: Custom fit Much more comfortable Athlete much more likely to wear it


Protection

Sports guards can: Absorb about 80% of the energy from a traumatic

hit to the mouth Protect teeth and jaws from fracture by a direct

blow or can cushion the upper and lower teeth when an athlete’s jaws are forced together by a blow to the lower jaw

Prevent laceration to lips for athletes with braces and protect dental work (bridges, veneers or crowns); Athletes should leave removable prostheses out when playing sports so they do not dislodge into throat

Heavy contact sports: 4mm thickness Less physical sports: 2mm thickness

Night Guards

Many patients grind their teeth (bruxing).

Most bruxing occurs during sleep.Other patients clench their teeth

during stressful times.A guard does not stop the habit, but it

does relieve the stress placed on the jaw joint.


Types of Materials

Hard Acrylic (methylmethacrylate resin and monomer) Usually fabricated in dental lab Requires more chair time Feels tight when first tried in

Thermoplastic sheets of poly(vinyl acetate)-polyethylene Easy to make, can be fabricated in office by

assistant, RDH, or DDS; can be sent to lab Less time to adjust

Laminates of hard and soft thermoplastic materials


Maintenance

Must instruct patient in proper homecare of the guard (Refer to table pg. 81)

Clean DAILY!Staining is common with all types of guards;

especially common with amalgams

Teeth Bleaching

Teeth bleaching has become an active part of many dental practices.

Patients request it, to make their teeth white.

Bleaching may be done in the office or at home.

Most bleaching agents are peroxide-based.

How Teeth Bleaching WorksThe enamel on the tooth crown is composed

almost entirely of mineral (97% by weight), with microscopic spaces between the enamel rods that contain water and organic material.

Stains accumulate within these small spaces in the enamel over time.

Teeth bleaching occurs when the hydrogen peroxide or non-peroxide bleaching material passes through the spaces in the enamel and oxidizes the stains, producing a lighter color.


Types of Stain

See Table 7-5, pg.82 Extrinsic

On tooth surface Can be removed by hand or ultrasonic scaling and

polishing Intrinsic

Internally stained, usually during development, or combination(ext and int)

Common foods/drinks that stain: Coffee Tea Red wine Cola Berries

Bleaching of Vital Teeth

Vital teeth have a healthy blood supply.When a person has his or her teeth

whitened in the dental office, a much stronger solution is used.

“Power” bleaching materials typically are similar to home bleaching materials but are much stronger.

These materials often are coupled with a dental light.

Bleaching of Nonvital Teeth

Teeth that have lost their blood supply (root canal) will turn dark.

This type of bleaching is isolated to one tooth.

Bleaching material is placed inside the pulp chamber, where it stays for several days.

Bleaching sometimes takes several applications.


Home Bleaching

Popular and cost effective Most used chemical for bleaching systems is 10 to 22%

carbamide peroxide Some products contain potassium nitrate to reduce tooth

sensitivity Gel is placed in custom fitted trays and worn for as little as

30 min twice daily to overnight May have reservoirs (help hold bleach in trays) Length of treatment varies, usually 2 weeks Recommended follow-up visits is every 2 to 3 weeks

Over-the-Counter Products

Types Bleaching strips Paint-on pastes Pre-loaded gel trays

Less caustic materialsDo not cause as much sensitivityAre less effective

Toothpastes that claim to whiten do not bleach the teeth, they remove surface stain only!


Restorative Considerations

Before bleaching, cavities should be filled and leaking restorations should be replaced to prevent excessive penetration of bleach into the dentinal tubules

Patients need to be informed that the color of existing restorations will not lighten with bleaching

During bleaching avoid foods/drinks that stain and smoking

Contraindications Bleaching is not for everyone.Some patients may be allergic to

components of the bleaching material.Sensitive teeth may exacerbate the

problem.Patients may have unrealistic

expectations.


Retreatment

Both in-office and home bleaching will fade with time and may require retreatment

Typically, patients find in 1to 3 years they want to get additional whitening

In-office usually requires full price to retreatHome bleaching gel can be repurchased for

additional whitening

Summary

Preventive practices in dentistry extend far beyond normal cleaning and fluoride application every 6 months.

Prevention involves the disease process and extends to injury, habit avoidance, and esthetics.

Preventive and Bleaching Materials Chapter 7. Fluorides Naturally occurring Have proved very...

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