Presentation on theme: "Prof. Hala Amer. Tooth decay is caused by the bacteria found in dental plaque. In general, the longer dental plaque remains on a tooth surface the more."— Presentation transcript:
Prof. Hala Amer
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
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 cant 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.
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 cant access and clean. Eventually, there is much less chance for the tooth decay.
b.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.
1.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
1. 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].
4.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).
Sealants are not needed in caries free teeth with shallow wide grooves. The patients 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.
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.
by 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
Chemical polymerized – (auto cured) Photopolymerized – (light cured)
Two liquids are mixed together (Mix catalyst with a base) Low cost Working time limited No control over set time
Hardened when exposed to light More working time than chemical When visible light is directed at sealant it starts the curing process No mixing is required Better control over setting time
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.
Purpose -Prevent contamination from saliva -Keep materials from touching oral tissues (unpleasant taste) Types of isolation - rubber dam - cotton rolls
Purpose - prepare area for conditioner - prevent dilution of the conditioner Use dry air - air dry for 10 seconds
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