A. If a person has caries in pits and fissures and it is undiagnosed or untreated it will spread. pit and fissure caries starts in enamel and then progresses to the second layer of the tooth. There are cases where decay is so minimal that it can be arrested in enamel by treating the tooth with fluoride and now in some cases with an ozone machine, however this is not common. Many dentists will carry out a preventive resin restoration when they see this type of decay. The fissures are drilled out along with the staining and decay and a white resin filling is placed over the top. This can usually be done without anaesthetic and the cavity remains only in dentine.