a. A dental sealant is a thin plastic coating that is bonded into the pits and grooves of a tooth. They are typically applied to the chewing surfaces of the back teeth (premolars and molars) where decay occurs most often.
B. How long have sealants been around?
b.) There's nothing new about the use of sealants. Dentists have been placing them since the late 1960's.
C. Why are they needed?
c.) Thorough brushing and flossing helps remove food particles and plaque from smooth surfaces of teeth. But toothbrush bristles cannot reach all the way into deep grooves of the teeth to extract food and plaque. Sealants protect these vulnerable areas by "sealing out" plaque and food.
D. When should sealants be applied?
d.) Typically children get sealants on their permanent molars and premolars as soon as these teeth come in; before any sign of a cavity has had a chance to form.
E. Are sealants only for children?
e.) The likelihood of developing pit and fissure decay begins early in life, so children and teenagers are obvious candidates, but adults can benefit from sealants as well.
F. Should sealants always be placed?
f.) Not all teeth require the protection that dental sealants can provide. After an examination, your dentist can let you know what they think is necessary.
G. How long do dental sealants last?
g1.) Most dentists would consider any sealant that remained intact for 3 to 5 years to be a success. One study's review of dental literature (Feigal, 1998) estimated a sealant loss rate (including partial loss) on the order of 5 to 10% per year.
g2.) They can, however, last much longer than that. 10 years might be considered the upper limit for one, although it's somewhat common that a dentist will see sealants that were placed during childhood still intact on adult patient's teeth.
H. How are sealants placed?
h.) Below is a diagram showing the steps used in the process of sealant placement:
Sources:
http://www.animated-teeth.com/tooth_sealants/t1_sealing_teeth.htm
http://www.mouthhealthy.org/en/az-topics/s/sealants