The effectiveness of completely and incompletely sealed first permanent molars on caries prevention.

Fissure sealants are effective caries preventive measure. However, a dilemma has been expressed more than once, whether incompletely sealed fissures provides sufficient protection against caries. Dental examinations were performed in 88 children, aged 8 and then 4 years later at 12 years. All first permanent molars (FPMs), as diagnosed at the age of 8, were divided into three groups: nonsealed, incompletely and completely sealed. Four years later caries incidence and changes in presence and quality of fissure sealant were analyzed. At the age of 8 and 12 mean DMFT were 0.73 ± 1.24 and 3.48 ± 3.04, respectively. 71.59% of the 8-year-olds and 78.41% of the 12-year-olds had at least one sealed FPM. At the age of 8, 154 FPMs were completely sealed and 42 FPMs were incompletely sealed. Four years later, 81.17%, 71.43% and 69.4% of FPMs were healthy (sound or with noncavitated caries) in the baseline groups completely sealed, incompletely sealed and nonsealed FPMs, respectively. Incompletely sealed fissures were more susceptible to caries development than completely sealed fissures. It is important that incompletely sealed fissures are resealed as soon as possible.