Retention of fissure sealants using two different methods of application in teeth with hypomineralised molars (MIH): a 4 year clinical study.

Objective: This was to evaluate the retention rate of fissure sealants applied to MIH molars with occlusal enamel opacities, using two different application methods after 4 years.

Methods: 54 children exhibiting molars with MIH aged 6-7 years, participated in the study. Methods: presence of at least 2 fully erupted caries-free maxillary or mandibular first permanent molars in the opposite sides of the mouth, both with occlusal enamel opacities without breakdown. Following parental consent, sealants were applied using a half-mouth experimental design. Group A: On a randomly assigned first molar on one side of the mouth sealants Fissurit were placed using a single bottle adhesive system (One-step prior to sealant application. Group B: Sealants were applied on the contra-lateral molar using the conventional etch and seal technique. Children were seen biannually when a preventive program was applied, without replacing any lost sealant.

Results: After 4 years, 47 sets of molars (94 teeth) were available for blind evaluation. Teeth in Group A presented a better retention rate; 70.2% were fully sealed, 29.7% partly sealed and none unsealed (lost sealant). Group B revealed 25.5% fully sealed, 44.6% partly sealed and 29.7% unsealed teeth. Methods: Differences between groups A and B were statistically significant (p<0.001). Also both groups revealed a decreasing retention rate over the 4-year period (p<0.001). There was no difference in dental caries increment rate and enamel breakdowns at the end of the study (p>0.01).

Conclusions: In hypomineralised molars with occlusal opacities sealants appear to have greater retention when applied using 5th generation adhesive systems prior to sealant.