In the name of GOD

Pit and fissure sealantsNarges shojaei

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the Centers for Disease Control and Prevention (CDC):

profession is dental caries, a chronic disease affecting more than 90% of adults aged 20 to 64 years.1 Although chronic diseases are among the most common and costly of all health problems, they are also among the most preventable

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Epidemiology of Pit and Fissure Caries

dramatic improvements in the prevention of caries have occurred :

I. fluoride exposure

II. enhanced awareness of the benefits of early care

III. increased access to dental care

IV. increased financial coverage by insurance companies

V. group plans, and government-funded programs of preventive and restorative dental procedures for children

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According to the National Institute for Dental and Craniofacial Research, 20% of the population bears at least 60% of the caries

• Dental caries :children living in poverty

• five time

• Minority populations

• specific tooth surfaces

• almost 25% of the decayed, missing, filled surfaces (dmfs) index

• 90% of caries in permanent

• two thirds of caries

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Why The occlusal surface is prone to caries ??

• immature tooth enamel high organic content

• pit and fissure morphology

• the molars take along time to fully erupt:1.5_2 years

• fluoride is less effective in preventing caries on the occlusal surfaces

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in 1955, Dr. Michael Buonocore revolutionized dentistry with the first reserch on adhesive dentistry

a physical barrier over susceptible pits and fissures and, in effect, “seal” out caries, preventing the carious process

In 1971 the first dental sealant, Nuva-Seal

the theory of sealing the occlusal surfaces of teeth in an effort to maximize “the power of prevention.”

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Sealant Effectiveness

Unquestionably, dental sealants prevent pit and fissure caries in both primary and permanent teeth

Healthy People 2010 set a goal for the prevalence of sealants in children and adolescents to increase to 50%

Low usage :

1. lack of confidence in the bonding of sealants to enamel

2. concern for sealing over caries

3. difficulty of achieving isolation

4. lack of reimbursement for sealant placement

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Current sealant utilization:

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How Sealants Work:1. Resin

2. glass ionomer

3. polyacid-modified resins

1. most commonly accepted material

2. by micromechanical retention

3. tooth must be clean and remain dry

4. enamel is etched with 35% to 37% phosphoric acid,

• different bonding mechanism• retention, chemcial bonding,

and chelation• hydrophilic 1. tooth is cleaned, and a tooth

conditioner of polyacrylic acid is applied

2. rinsed and dried3. Aply gi

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Types of sealants:

variety of materials, colors, and viscosities

Resin-based sealants :

• unfilled, filled

• clear, colored

• visible light–polymerized, autopolymerizing (chemically cured

• fluoride-releasing materials

earliest sealants :autopolymerizing but now replaced by self cured sealants

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Why?

1. sets in 10 to 20 seconds

2. No mixing and air bubble

3. the viscosity of the sealant remains constant

4. sealant material does not set until it is light activated

5. similar retention rates and similar strengths.

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Color:

available as clear or opaque white:

Advantage of an opaque sealant:

1. easy to see during application

2. easy to monitor its retention at a recall visit

3. . Assessment of a clear sealant requires tactile

4. No apparent difference in the clinical efficacy of either type of sealant

being able to quickly and correctly assess

sealant retention is clinically important.

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newer materials

1.color properties:Clinpro (3M ESPE, St. Paul, Minn.)

• that is pink upon application and turns white when cure

• . This color change provides no clinical advantage and has been described as a “perceived marketing benefit

2:(Ivoclar Vivadent, Amherst, N.Y.).

• containing a photochromic dye

• correct wavelengths :change from clear/yellow to green

• is clinically relevant because it may assist a provider in assessing the sealant’s retention upon recall examination

• But:using a polymerizing lamp

• have similar properties andcaries-protective as other resin-based sealants

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Filler Content:physical characteristics

unfilled sealants deeper into the fissures :

• low viscosity:longer resin tags, and therefore be better retained

• other studies have found similar retention rates with unfilled and filled sealants

• clear advantage of the unfilled sealant :

1. lower rates of microleakage

2. better penetration into the fissures

3. occlusal adjustment is not necessary(necessity to adjust the occlusion increases the time and cost of the procedure)

Viscosityflowability,and resistance to wear

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flowable composite: inferior retention and microleakage

utilizing a bonding agent improves fissure penetration and decreases microleakage

need for a bonding agent and occlusal adjustment

the conventional unfilled resin-based sealant appears to be the most appropriate preventive therapy.

Fluoride-Releasing Sealants:salivary fluoride levels are the same before and after

no long-lasting release of fluoride

marketing benefit by manufacturers

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Glass Ionomer:as an alternative to resin-based

1. fluoride-releasing

2. recharging ability

3. moisture toleration

4. easy application

But poor retention rates the use of resin-based sealant

usage:

ART(high-viscosity sealants placed with “finger pressure)

compromise sealant placement

Preventin of caries resin baced sealant

Retention resin based sealant16

Polyacid-Modified Resin Composites (Compomers):• the esthetic property of composite

• fluoride-releasing property and adhesion of glass ionomer

similar to composites

Similar to GI:release fluoride( GI )

poor marginal integrity,retention and occlusal wear

• contain no water hydrophobic

• polymerization• lack the ability to

bond to tooth• require bonding

agents

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Who Really Needs Sealants?

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Age at Placement:

• caries incidence occurring shortly after tooth eruption and then tapering

• occlusal surface was most vulnerable(first few years after eruption )

• that fluorides may have caused a delay in pit and fissure caries resulting in occlusal surfaces that decay at a later age

• adults should receive sealants when the tooth or the patient is at risk of experiencing caries

• place a sealant should not be based on how long ago the tooth erupted but on the clinical impression of whether a sealant is necessary to prevent caries

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Which Teeth Should Be Sealed?

Traditionally: non carious first and second permanent molars

with deep fissures

now any tooth at risk of developing caries

• including primary teeth

• permanent molars with incipient, noncavitated lesions, and/or premolars.

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Indications :

deep, retentive pits and fissures”(cause wedging or catching of an explorer)

stained pits and fissures with minimal appearance of decalcification or opacification (no cavitation)

no RG or clinical evidence of interproximal

use of other preventive treatment, such as fluoride therapy

possibility of isolation

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Contraindications :

well-coalesced, self-cleaning pits and fissures

interproximal caries in need of restoration

interproximal lesions or restorations with no preventive plan/treatment to inhibit caries formation

life expectancy of the primary tooth is limited

no possibility of isolation from salivary (due to either eruption status or patient behavior.)

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Diagnosing Occlusal Caries

dentists correctly diagnose only 42% of cases

Usage of expelorer : yes or no ?

No :

Yes :

eliminate plaque in the fissures

determine surface roughness of incipient lesions

time-tested tool

Tactile diagnosis :specific criteria for detection and diagnosis of pit and fissure lesions

does not increase dentists’ ability

tactile examination unreliable

enamel defects(cavitation

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Caries is present when :

1. explorer catches or resists removal after the insertion into a pit or fissure

2. when this is accompanied by one or more of the fallowing

• A softness at the base of the area

• Opacity adjacent to the pit or fissure

• Softened enamel adjacent to the pit or fissure

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the use of explorers is not necessary for the detection of early lesions

Visual examination alone (of a clean, dry tooth) is sufficient to detect early lesions

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Sealing Over Incipient Caries:

If sealants are applied properly and are monitored periodically, caries arrest beneath a sealant

sealant placement greatly reduces the number

of carious lesions that progress

decreases the viable bacteria

Acid etching eliminates 75% of the viable microorganisms

100% reduction in total viable bacteria

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. Whenever a situation occurs in which the practitioner is certain that a restoration is not yet warranted but is unsure of whether the fissure is simply stained or is exhibiting signs of incipient caries, the practitioner should err on the side of placing a sealant rather

than monitoring the lesion.

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Cleaning the tooth:

For flow in the fissures it must be cleand:several method:

historically:pumice ,prophy cap ,bristle brush

Other method: explorer ,air water spray or dry bristle brush

Sup cleaninig method: cavitron prophy-jet(air polishing)

Advantage: remove more debry ,increase resin tags

but not standard

equipment cost and complication

No difference in retention29

Mechanical preparation:

Invasive technique minimally described:

Enameloplasty and fissurotomy:

Better penetration

Increase surface area fore etching

Dosent decrease microleakage

Air abrasion :

another technique but cant substitute etching

Some studies show that air abrasion in combination with

Etching improved retention30

Disadvantage :

• limits delegation of sealant placement to axilliaries

• Decrease cost effectiveness

• Expose child to handpiese

the plaque should be removed but removal of tooth structure by bur unnecessary

Effect of fluoride treatment

Multiple studies confirm sealant bond strength and retention

Are not affected by fluoride treatment before sealant

application

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Factors affecting sealant success:

Etching

Drying agent and time

Curing

Isolation

Time of sealant placement

Auxiliary application

Four-handed delivery

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Etchant :

Phosphoric acid , self etching system , liquids and gel

Historically:ething:60 s and rinsing time :at least 10 s

Etching time for fluoride tooth should be increased

Usual recommendation : etching:30 s rinsing :20 -30 s

It is important that removal of all etching agent from surface

No difference between liquids or gel system in bond strength

And retention

Self etching needs a separate etching step

Not recommended

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Drying agent and time :

Applying alcohol or acetone Because of Resins that are hydrophobic agent :

Don’t decrease microleakage or increase retention

No recommended drying time : occlusal surface should have chalky

Or frosted appearance

No chalky : etching again

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Curing :Phothoiniatiator (camphoroquinone) absorb energy from blue light

(479 nm) that cause low viscosity monomer to matrix polymer

Sealant must be adequately cured to obtain purported physical properties

Most widely used:

1: QTH curing light:

1. Reguire cooling fan

2. Low cost

3. Easy to maintain and repair

4. Curing composite in 20 s

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2: LED : First LED curing had low energy output ,recent LED increase out put intensity

Latest LED s advertise 5s curing in<torbo> or <plasma> method

May be concerns with such quick cures:

1. Significant rise temperature(pulp injuries)

2. May cause undesirable physical properties

3. Increase polymerization contraction

4. More internal stress

5. Reduced flexural fatigue

Highest level of cure:40 s exposure with

the tip of the Light source placed directly

over sealant36

Several factors affect level of cure :

1. Shade of the materials

2. Filler content

3. Thickness of material

4. Intensity of light curing

5. Distance between light source and sealant surface

clear sealant can be cured to deeper level than opaque sealant in same curing time

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Isolation

Resin based sealant are moisture sensitive:

Saliva prevent the formation resin tag decrease retention

Isolation is a critical step to the success of sealant

Considered a key concept in clinical procedures

Rubber dam:

Some studies show increased retention

Whenever possible especially if cocorurrent

Operative treatment is provided rubberdam

should be used

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Timing of sealant placement :

• Correlated with overall retention:

• Partially erupted teeth require repair or replacement more than other

• When operculum extended over distal marginal ridge:50% of teeth to be resealed

• When it was at level of marginal ridge : reseal 26%

• When achieving isolatoin is difficult or precooperative :using

Glass ionomer

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Use of intermediate bonding agent :An intermediate layer between tooth and sealant

advantage

Increase retention rate

Decreased microleakage

Increased penetration of sealant into fissures

Not only permanent tooth : primary as well

Hypomineralized teeth(at higher risk than normal)

disadvantage

Proper sealant placement technique

Increased chair time

Cost

whould inhance sealant retention on clinical

Situation 40

Auxiliary application :

No difference in retention of sealant when applied by dentist or trained dental auxiliary

Four-hand delivery : No difference in retention

Expert opinion support use of trained dental assistant

Improve quality and efficiency of sealant placement

Isolation

Shorten placement time

Reduce fatigue and enhance patien care

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School based sealant program:

Increase sealant using

Reduceing careis

Provide prevention service to child less likely to receive dental care

It is important and effective public health approach that complements clinical care systems

in promoting oral health

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Other uses of sealant:

1. Sealing over the restoration

2. Repairing margin of restoration

3. Preventing demineralization around orthodontic brackets

Reduce microleakage

Decreased incidences of recurrent caries

Increase longevity of restoration through repair of marginal defect

No loss of tooth structure and low cost

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Clinical procedure:1:Isolation:

Most common method :cotton roll

For maxillary isolation :

tri angular buccal shield :angle posterior

Cotton roll : maxillary vestibule

Mirror is used during entire procedure

mandibular isolation :

Cotton roll : two vestibule

Cotton roll holder or hand may be

used

Triangular shield on buccal

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Etching :

With 37% phosphoric acid

Including pit and fissure and lingual groove of max molars

and buccal pit of man molars

Etching should extend up cuspal line ,2 -3 mm beyond anticipated

margin of sealant

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Rinsing and drying :

Air-water spray and high volume suction

Most manufactors recommended :20-30 s

The goal of rinsing is removal all of etchant from surface

Sealant application and polymerization:

Should be applied to all pit and fissures

With : expelorer ,PICH, or small brush

Shouldn’t be over filled

• Does not extend past the etched area

• Limit occlusal interence

• Ensure adequate depth of cure

Small bubbles should be teased out of the material before polymerization

• Exposure time of 40 s is more appropriate 46

Evaluating the sealant : Visually an tactilely examine the sealant before removing isolation

Void or bubble : material can be directly added

Sealant retention :examine by attempting to dislodge by expelorer

If sealant dislodge :

Fissure inspected for Remaining debri :re etched…

Sealant pooled on distal margin created ledge tht should be removed

Sealant misplaced on inter proximal should be removed

Un polymerized layer(BPA):removed by pomice or rinsing

Occlusion Adjustment :

Yes:filled sealant and flowable composite

With:com finishing bur(high spead

,round bur,stone(low spead)

MC:centric stop on enamel

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Periodic evaluation: It should be evaluated at every recall visit

Partial or complete loss of material failure

If only part of sealant remain : attempts can be made to dislodge with expelorer ,if it remain :no no need to remove this

MC :

5% -10% of sealant need to repaired or replaced yearly

Partialy or completely,discolored or defective old sealant should be removed

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Troubleshooting sealant placement :

If sealant debonds upon immediate evaluation:

1. Debris remains on the fissure

Cleaning,re etching and apply material

2 .Saliva contaminated the enamel

Re etched ,dry and resealant

3. The tooth wasnot completely dry after the rinsing step

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