In the same 8-year-old patient, another primary molar has only occlusal (pit and fissure) caries confined to enamel. What is the most appropriate treatment?

For occlusal caries that has progressed into dentin (cavitated lesion), a restoration is indicated. The most appropriate treatment for an occlusal carious lesion in a primary molar in a cooperative 8-year-old is a composite resin restoration (or amalgam). Sealants are appropriate for non-cavitated (early) lesions or caries prevention in healthy pits and fissures — not for frank cavitated caries. SDF arrests caries but does not restore the tooth and leaves a black stain, making it more appropriate when conventional treatment is not possible. If the question specifies 'occlusal caries' without specifying cavitation, composite resin restoration is the standard choice.