Sealants are effective in preventing caries:*Only in permanent molarsOnly on non-demineralized surfacesIn primary molarsOnly with enamelplasty

Sealants are effective in preventing caries in both primary and permanent molars. They work by creating a barrier that prevents bacteria and food particles from settling into the grooves and pits of the teeth, which are common areas for caries to develop.

Here's a step-by-step breakdown:

1. Sealants are applied to the chewing surfaces of molars where decay occurs most often. This includes both primary (baby) and permanent (adult) teeth.

2. The process of applying sealants involves cleaning the tooth surface, preparing it with a special solution, and then applying the sealant material. This can be done on both demineralized and non-demineralized surfaces.

3. Enamelplasty, or the process of reshaping the tooth's surface before applying a sealant, can improve the sealant's adherence to the tooth. However, sealants can still be effective without enamelplasty.

So, to answer your question, sealants can be effective in preventing caries in all of the situations listed, not just one.