ALEXANDRINA MUNTEAN, ANCA MESAROS, DANA FESTILA, MARIOARA MOLDOVAN, MICHAELA MESAROS IN VITRO MICROLEAKAGE EVALUATION AROUND THREE TYPES OF DENTAL SEALANTS Dental sealants are a specific prophylactic alternative for fissures with an irregular morphology. The aim of this in vitro study was to evaluate dye penetration around three materials recommended for fissure sealing with a different composition. Thirty teeth were sealed according to manufacturer’s instructions as follows (n=10): Group I, light-cured unfilled resin-based sealant, Admira Seal® (Voco GmbH); Group II, light-cured filled resin-based sealant, Fotoseal® (S.C.Remed Prodimpex S.R.L., Bucharest, Romania); Group III, resin modified glass ionomer sealant without varnish, GC Fuji Triage® (GC Corporation). The teeth were thermocycled, then immersed in 0.5% basic fuchsine dye for 24 h. The teeth were sectioned buccal-lingually in order to obtain one section per tooth in the middle of the occlusal surface and the sections were examined at 40x with an inverted microscope. Dye penetration was recorded (mm) using specific software and related to the total length of the sealed fissure. Average values for each group were subjected to statistical analysis by Student’s t and Kolmogorov-Smirnov tests (p<0.05). Significantly less dye penetration was recorded for both resin-based sealants compared to the resin modified glass ionomer sealant, with no difference between the filled and the unfilled resin sealant (p=0.34). The resin-based sealants were more effective in sealing the fissures than the resin modified glass ionomer cement sealant.