In this case, we have a classic example of a leaking sealant. The interface between filling and sealant at the occluso-lingual groove of #3 has broken apart and been seeping with each day getting into the dentin beneath the filling and the tooth. The interface between the sealant and the filling breaks and starts leaking. I identified a small area of grayness at the marginal interface. These types of failures rarely show up on a radiograph, but, MUST be visually identified by the dentist. By the time it shows up on an x-ray, it would be very deep and very large. Luckily in this case we were able to identify it early and simply replace the failing restoration with a new clean composite that should last for many years to come.
People have asked me in the past, ‘Why do you only seal some teeth, but, not others?’ Only teeth in high risk patients and high risk teeth should be sealed. (Factors which determine caries risk are: whether the mother of the patient has caries, caries in the primary teeth, homecare – if they are brushing 2x per day, using a fluoridated toothpaste, and whether the individual tooth has deep grooves, and socioeconomic status.)