Abstract: Abstract Objectives To evaluate the clinical effect on prosthesis of sub gingival wedge-shaped defect with gingival retraction cord and gingival retractor. Methods 240 teeth with wedge-shaped defect in sub-gingival depth of 1-2mm were randomized into gingival retraction cord group, gingival retractor group and combined group with 80 teeth in each group. CLEARFIL SE BOND system and CLEARFIL AP-X? composite resin were used in each group to bond and fill the defects. Follow-up study was carried out 1 year after treatment to examine the filling material loss and gingival health status. Results In the combined group, filling material in 4 teeth fell off, and 3 teeth of the 76 teeth whose filling material was in good condition got gingivitis. The loss rate of the filling material and the incidence of gingivitis in the combined group were 5.00% and 3.95%. In the gingival retraction cord group, filling material in 12 teeth fell off, and 9 teeth of the 68 teeth whose filling material was in good condition got gingivitis. The loss rate of the filling material and the incidence of gingivitis in the combined group were 15.00% and 13.24%. In the gingival retractor group, filling material in 15 teeth fell off, and 11 teeth of the 65 teeth whose filling material was in good condition got gingivitis. The loss rate of the filling material and the incidence of gingivitis in the combined group were 18.75%、16.92%. The loss rate of the filling material and the incidence of gingivitis in the combined group were lower than those of gingival retraction cord group and gingival retractor group, and there is a statistical significance in difference (p<0.05).Conclusions Utilization of gingival retraction cord combined with gingival retractor in the restoration of sub-gingival wedge-shaped defect can efficiently improve the overall quality of the restoration.

Key words: wedge-shaped defect, gingival retraction, clinical effect