Preventive resin restorations should only be placed if there is decay present. If there is no decay, then a sealant should be placed as a preventive measure. Sealants aren’t meant to last forever, but restorations are irreversible, invasive procedures that are meant to last. Dianne Glasscoe quoted Dr. Simonsen saying, “To place a restoration (an irreversible, invasive procedure) when a preventive treatment is indicated, is an egregious breach of the trust put in us by our patients. When caries is suspected, an exploratory widening of the fissure with either air abrasion or a small bur to such a point as to be able to say with certainty that there is caries present (and then remove it and place a PRR), or to confirm that caries is not present (either seal or use PRR if enamel has been penetrated) is justified.”
http://www.rdhmag.com/articles/print/volume-20/issue-8/columns/staff-rx/sealants-vs-prr.html