Abstract: Objective: Observe the adhesive residue around the implant restoration after using different bonding methods, to analyze and compare the clinical effects of various bonding methods. Methods: 90 locking-taper implants were implanted on the posterior teeth from June 2018 to June 2019 were randomly divided into rubber barrier group(group A), adhesive substitute group(group B) and direct adhesive group(group C), each group was divided into three subgroups according to the relationship between crown edge and gingiva. All selected cases were bonded in the mouth, remove the excess adhesive visible to the naked eye and X-ray was taken to confirm the absence of adhesive residue. The abutment and crown were then removed to observe and record the adhesive residue. Finally, the abutment crown was placed in the mouth after removing the residual adhesive. Results: The deeper the crown edge is under the gum, the more adhesive remains. There were statistically significant differences in adhesive residues between different subgroups of each group. When the crown edge was at the same subgingival depth, there was no significant difference in adhesive residues between group A and group B. There was no significant difference in adhesive residues between the three groups when the crown edge was at the level of the gingiva. Conclusion: The position of the crown edge would affect the adhesive residue, and the deeper the subgingival depth, the more adhesive residue. When the crown edge is located under the gingiva, both the rubber barrier method and the adhesive substitution method can effectively reduce the amount of adhesive residue, but the adhesive substitution method is more convenient to operate and has a better effect on reducing adhesive residue.

Key words: Implant restoration, Adhesive residue, rubber barrier, adhesive substitution