Do sealants really prevent cavities?

Yes — studies consistently show sealants reduce cavities in the deep grooves of molars by well over half compared to no sealant. They work by physically blocking the grooves where a toothbrush bristle can’t reach and food and bacteria collect. They’re most valuable on six-year molars and twelve-year molars right after they come in, before decay has a chance to start. Sealants aren’t a substitute for brushing or checkups — they protect one specific vulnerable spot, not the whole tooth.