In Vitro Retentive Effect of Groove, Sandblasting, and Cement Type on Stainless Steel Crowns in Primary Molars.

PURPOSE: The purpose of this study was to evaluate and compare the effect of placing vertical grooves, sandblasting, and luting cements on the retention of stainless steel crowns (SSCs). METHODS: Eighty extracted primary molars were mounted in acrylic blocks. Specimens were divided into Group 1 (RelyX U200) and Group 2 (Smart Cem2). Teeth in each group were further subdivided into Subgroup A (no vertical grooves and no sandblasting), Subgroup B (vertical grooves), Subgroup C (sandblasting of crowns), and Subgroup D (vertical grooves and sandblasting of crowns). After cementation, SSCs were pulled off using a universal testing machine. One-way analysis of variance was used for statistical analyses. RESULTS: In Groups 1 and 2, the highest retentive strengths were found in Subgroup D (1,124 and 783 kPa, respectively), followed by Subgroup C (1,066 and 748 kPa, respectively), Subgroup A (762 and 356 kPa, respectively), and Subgroup B (743 and 314 kPa, respectively). Retentive strength in Group one was significantly higher than in Group two; Subgroups A and B were significantly lower than C and D. CONCLUSIONS: RelyX U200 showed higher retentive strength than Smart Cem2. Sandblasting increased the retention strength, whereas a vertical groove had no significant effect on retention.