2Why 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
4What 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
5Why 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.
7When 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.
8In 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.
13How does a sealant work?a. Bonding the plastic resin into the grooves ofthe 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.
14A sealant does not penetrate the full depth of the fissure, but it isolates down in the depth of the fissure a layer of bacteria thatbecomes non-pathogenic, becauseit becomes deprivedfrom nutrients, waterand air.
16Requirement 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 capillarity5. Rapidly polymerized6. Low solubility in oral fluids7. Enough strength for facing mastication
17Indications 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].
18Caries 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.
19Sealants 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).
20Contra-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.
21Caries is present on other surfaces of the same tooth, where compound restoration usually extend to the occlusal surfaces.
22Proper 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 agesThe 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.
23How does sealant bind to the tooth by mechanical retention
24What 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
26Two types of sealants Chemical polymerized – (auto cured) Photopolymerized – (light cured)
27Chemical Polymerized (Autopolymerized) Two liquids are mixed together(Mix catalyst with a base)Low costWorking time limitedNo control over set time
28Photopolymerized (visible-light-cured) Hardened when exposed to lightWhen visible light is directed at sealant it starts the curing processNo mixing is requiredBetter control over setting timeMore working time than chemical
29Steps 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.
30Isolate the teeth to be sealed PurposePrevent contamination from salivaKeep materials from touching oral tissues (unpleasant taste)Types of isolation- rubber dam- cotton rolls
31Dry tooth/teeth to be treated Purpose- prepare area for conditioner- prevent dilution of the conditionerUse dry air- air dry for 10 seconds
32Apply conditioner Phosphoric acid (37%-50%) - Apply with a brush - Use gentle dabbing motion.Purpose- create surface irregularities- increase size of micro-spaces betweenenamel rods- remove bacterial plaque
34Rinse thoroughly Purpose Maintained dry area - remove excess acid - prevent saliva from reaching areaMaintained dry area- remove and replace wet cotton rolls- suction constantly applied
35Dry 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.
36Apply 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 tipsIf using chemical mix, do not disturb the mix!!
37Curing light Always wear eye protection Hold tip of light as close as possible to the tooth surface without compromising the sealant.30 – 45 seconds
39Annual recall is adequate to reseal lost sealants and, thus, maintain sealant integrity.
40We can improve the retention of sealants to nearby 100% by: Proper placement of the sealant,checking it annually, andreplacing it when needed.
41Sealant retention after a single application 92 – 96% 1 year67 – 82% 5 years 41 – 57% years20% years
42Guidelines for sealant placement Sealants are cost-effective if applied to high caries risk patientsSealants are not cost-effective if applied to all patients without regard to diet, caries activity, etc.
43The cost of screening large numbers of individuals to identify those at risk for caries might be excessive.
44At-risk teeth determined by: Pit and fissure morphologyCaries activity in mouth