The effect of Fluoride varnish on the retention of full coverage crowns cemented by Self-adhesive cement RelyX U200

Introduction: Due to the importance of the retention on long term success in fix prosthodontics and its known complications effect of insufficient retention, and due to lack of sufficient information about the effect of Fluoride varnish on the retention of full coverage crowns cemented by Self-adhesive cement (RelyX U200), in this study we evaluated the effect of Fluoride varnish on the retention of full coverage crowns cemented by Self-adhesive cement (RelyX U200). Methods: In this experimental study, 20 intact human premolars after preparation and create 0.5 mm chamfer finish line above the cementenamel junction, allocated to the two groups of cases (10 teeth treated with Fluoride varnish) and control group (10 teeth without surface treatment). Full metal crowns were made of base metal with a ring (for retention test). Then all the crowns were cemented with RelyX U200 cement and the retention test was performed using a universal testing machine. Data were analyzed with t-test (SPSS Ver:22). Result: The tensile strength of Fluoride varnish group (153.92±67.50) is significantly lower than control group (458.32±165.52) (P=0.0001). Conclusion: Fluoride varnish has negative effect on the tensile strength of Self-adhesive cement (RelyX U200).