Abstract: Objective: To observe the rate of the sealant reservation and caries prevention of pit and fissure sealant on the primary molars etched with self-etching adhesive and phosphoric acid within 18 months. Methods: There were 75 children including 300 second primary molars to be studied. The split mouth design was used in this study. One side of the mouth was randomly chosen for the experiment group using self-etching adhesive way, and the other side using phosphoric acid way was for the control group. Operation time, the sealant reservation rates and the caries condition after 6, 12 and 18 months were recorded. Results: The operation time for the teeth of the experiment group (103±10s) was statistically shorter than that of control group (210±24s, P<0.05). After 6, 12 and 18 months, the retention rates were 98.67%, 97.33% and 92.67% in the experiment group, while 97.33%, 96.67% and 90% in the control group. The caries rates were 0%, 0.67% and 2.67% in the experiment group, while 0.67%, 1.33% and 4% in the control group. However, there was no significant difference between two groups. Conclusion: The use of self-etching adhesive for primary molar pit and fissure sealant can shorten the operation time, reduce the need of children compliance, and is suitable for clinical application.

Key words: Primary molar , Self-etching adhesive, Pit and fissure sealant , Retention rate