Comparative study on microleakage and compressive strength of four fissure sealants

AIM: To evaluate the microleakage and compressive strength of 4 fissure sealants.METHODS:28 caries-free premolars extracted for orthodontic reasons from 12-16 years old volunteers were collected and randomly divided into 4 groups(n=7).Fissures were respectively sealed with Helioseal F,VOCO Fissurit F,AscentMT,and ClinproMT pit and fissure sealant.Then the teeth were thermocyclinged for 100 times.5 teeth in each group were stained with 20 mg/L methylene blue for 24 hours,and then were sectioned for the evaluation of microleakage.The remaining 2 teeth in each group were used for the observation of marginal adaptability of fissure sealants with tooth interface by SEM.9 disc-like specimens(with the thickness on 4mm diameter on 4mm) were prepared for each material and kept in normal saline at 37 ℃.The compressive strength of the specimens was examined 1 d,28 d and 63 d afer saline treatment(N=3).RESULTS:There was no significant difference in the microleakage among the 4 sealants,VOCO Fissurit F fully penetrated into the bottom of the fissure and fully integrated with enamel observed by SEM.The interface between Helioseal F,AscentMT or ClinproMT sealants and enamel was close.Compressive strength value of AscentMT was significantly higher than that of other 3 sealants at all measurement days,but air bubble and crack were found.CONCLUSION:VOCO Fissurit F has excellent marginal adaptation.AscentMT has strong compressive strength.