Abstract: Objective Through a 2year followup study on the effect of the two enameloplasty sealant techniques, to compare the efficacy of the application of phosphate etching and selfetching on preventing the caries of pit and fissure. Methods With splitmouth comparison,100 children aged 8 were selected to study, which means 400 first permanent molars were involved. After the enameloplasty, the left teeth of the mouth were selfetched (experimental group),and the right ones were phosphate etched (control group). The retention rates of sealing agent at 6 months,12 months and 24months were followed up. Results There were no significant differences between the phosphate etching and selfetching adhesive in the retention rate of sealing agent at 6 months, 12 months and 24 months（P>0.05）. Conclusions The effect of the two etching adhesives in enameloplasty sealant technique is satisfying.

Key words: enameloplasty sealant technique, phosphate etching, selfetching, the retention rate of sealing agent