Dental Sealants Prof. Hala Amer

Why are dental sealants placed on teeth? Tooth decay is caused by the bacteria found in dental plaque. In general, the longer dental plaque remains on a tooth surface the more likely it will be able to form cavity

Strep mutans Strep sorbinus Lactobacillus

What are dental sealants? Dental sealants are plastic resins which bond to the pit and fissure surfaces of enamel to prevent occlusal caries in posterior teeth

Why pit & fissure surfaces in posterior teeth? Posterior teeth, especially molars, can be difficult for a person to clean because the pits & fissure found on their chewing surface are deep and narrow.

When the person brushes his teeth, not all the tooth brush bristles gain access into the depths of the pits and fissures, because they are simply too narrow and the tooth can’t be cleansed effectively.

In some instances the enamel that lies at the base of the grooves is thinner than the enamel that covers the other surfaces of the tooth. Occlusal decay will take less time penetrating through the enamel layer and progressing into the inner parts of the tooth.

How does a sealant work? a. Bonding the plastic resin into the grooves of the tooth creates a physical barrier sealing off pits and fissures and a smooth tooth surface. Dental plaque can be removed more easily and effectively. There are no longer any area on the occlusal surface of the tooth that the toothbrush bristles can’t access and clean. Eventually, there is much less chance for the tooth decay.

A sealant does not penetrate the full depth of the fissure, but it isolates down in the depth of the fissure a layer of bacteria that becomes non-pathogenic, because it becomes deprived from nutrients, water and air.

Requirement of a sealant material: Adhesion to enamel for extended periods. 2. Simple clinical application. 3. Non-injurious to oral tissues. 4. Free flowing and capable of entering narrow fissures by capillarity 5. Rapidly polymerized 6. Low solubility in oral fluids 7. Enough strength for facing mastication

Indications of sealants placement: Occlusal pits and fissure, buccal pits and cingulum pits in caries free teeth. 2. Newly erupted teeth with deep and narrow pits & fissures. 3. Patients with previous caries experience [High caries susceptibility].

Caries free occlusal surfaces during early teen age where the contra lateral tooth surface is carious or restored, this is because teeth on opposite sides of the mouth are usually equally susceptible to caries. 5.

Sealants are also indicated to be applied on the teeth of adults: if there is evidence of existing or risk for caries susceptibility, such as subjects with excessive intake of sugar, or those with drug or irradiation induced xerostomia, any systemic disease with caries susceptibility, and in normal subjects with orthodontic or other appliances (where there is increased plaque accumulation).

Contra-indication of fissure sealants Sealants are not needed in caries free teeth with shallow wide grooves. The patient’s behavior does not permit use of adequate dry field techniques throughout the procedure. There is an open occlusal carious lesion. There is already a large occlusal restoration.

Caries is present on other surfaces of the same tooth, where compound restoration usually extend to the occlusal surfaces.

Proper age of sealant application when sealant is indicated The proper age for sealing deciduous teeth will be 3-4 years. The proper age for sealing first permanent molars will be 6-7 years, while ages The proper age for sealing second permanent molars and premolars is 11 to 13. Sealant retention may be equally satisfactory if properly applied on deciduous as well as permanent teeth.

How does sealant bind to the tooth by mechanical retention

What is mechanical retention ? Physical adherence of one substance to another. Acid etching (conditioner) leaves micro-spaces between the enamel rods which when filled with the sealant it locks it into these spaces

Two types of sealants Chemical polymerized – (auto cured) Photopolymerized – (light cured)

Chemical Polymerized (Autopolymerized) Two liquids are mixed together (Mix catalyst with a base) Low cost Working time limited No control over set time

Photopolymerized (visible-light-cured) Hardened when exposed to light When visible light is directed at sealant it starts the curing process No mixing is required Better control over setting time More working time than chemical

Steps in placement Select teeth according to criteria and indications. Clean the tooth surface by removing deposits & debris with a mixture of pumice & water and suction. Recheck area with explorer to ensure all debris is removed.

Isolate the teeth to be sealed Purpose Prevent contamination from saliva Keep materials from touching oral tissues (unpleasant taste) Types of isolation - rubber dam - cotton rolls

Dry tooth/teeth to be treated Purpose - prepare area for conditioner - prevent dilution of the conditioner Use dry air - air dry for 10 seconds

Apply conditioner Phosphoric acid (37%-50%) - Apply with a brush - Use gentle dabbing motion. Purpose - create surface irregularities - increase size of micro-spaces between enamel rods - remove bacterial plaque

How long? Acid etch gel Permanent teeth – 15-20 seconds Primary teeth – 20-30 seconds Contaminated w/ saliva – 10 seconds

Rinse thoroughly Purpose Maintained dry area - remove excess acid - prevent saliva from reaching area Maintained dry area - remove and replace wet cotton rolls - suction constantly applied

Dry enough? Surface should appear dull and chalky white when air dried (20 sec) Primary teeth or older permanent teeth may need a repeat conditioning treatment.

Apply sealant Placement - only 2 teeth per mix - start with the most posterior tooth - flow into the deepest portion of the fissure - avoid ridges and cusp tips If using chemical mix, do not disturb the mix!!

Curing light Always wear eye protection Hold tip of light as close as possible to the tooth surface without compromising the sealant. 30 – 45 seconds

Annual recall is adequate to reseal lost sealants and, thus, maintain sealant integrity.

We can improve the retention of sealants to nearby 100% by: Proper placement of the sealant, checking it annually, and replacing it when needed.

Sealant retention after a single application 92 – 96% 1 year 67 – 82% 5 years 41 – 57% 10 years 20% 15 years

Guidelines for sealant placement Sealants are cost-effective if applied to high caries risk patients Sealants are not cost-effective if applied to all patients without regard to diet, caries activity, etc.

The cost of screening large numbers of individuals to identify those at risk for caries might be excessive.

At-risk teeth determined by: Pit and fissure morphology Caries activity in mouth

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