Characterisation and microleakage of a new hydrophilic fissure sealant-ultraseal XT®hydro™

Objectives: the aim of this study was to characterise the new hydrophilic fissure sealant,ultraseal xt® hydro™ (ultradent products,usa),and to investigate its in vitro resistance to microleakage after placement on conventionally acid etched and sequentially lased and acid etched molars. material and methods: the sealant was characterised by fourier transform infra-red spectroscopy (ftir),scanning electron microscopy (sem),energy dispersive x-ray analysis (edx),and vickers indentation test. occlusal surfaces of extracted human molars were either conventionally acid etched (n=10),or sequentially acid etched and laser irradiated (n=10). ultraseal xt® hydro™ was applied to both groups of teeth which were then subjected to 2,500 thermocycles between 5 and 55°c prior to microleakage assessment by fuchsin dye penetration. results: ultraseal xt® hydro™ is an acrylate-based sealant that achieved a degree of conversion of 50.6±2.2% and a vickers microhardness of 24.2±1.5 under standard light curing (1,000 mwcm-2 for 20 s). fluoride ion release is negligible within a 14-day period. sem and edx analyses indicated that the sealant comprises irregular submicron and nano-sized silicon-,barium-,and aluminium-bearing filler phases embedded in a ductile matrix. laser preconditioning was found to significantly reduce microleakage (mann-whitney u test,p<0.001). the lased teeth presented enhanced surface roughness on a 50 to 100 μm scale that caused the segregation and concentration of the filler particles at the enamel-sealant interface. conclusion: laser preconditioning significantly decreased microleakage and increased enamel surface roughness,which caused zoning of the filler particles at the enamel-sealant interface. © 2016,faculdade de odontologia de bauru. all rights reserved.