The Retention of Stainless Steel Molar Bands on BioFlx® Crowns With Different Types of Luting Cements: An In Vitro Study.

Purpose: To evaluate the bond strengths of stainless steel molar bands (SSMBs) on NuSmile^® BioFlx^® crowns (BFCs) using glass ionomer cement (GIC), resin-modified glass ionomer cement (RMGIC), self-adhesive resin cement (SARC), and zinc polycarboxylate cement (PXC). Methods: Eighty BFCs (size 4) and SSMBs (size 35+) were closely fit on the crowns. Four different types of luting cements (20 per group: group one-GIC; group two-RMGIC; group three-SARC; and group four-PXC) were used to cement the SSMBs onto the BFCs. The bond strength between the SSMBs and the BFCs was tested using a universal testing machine. The adhesive remnant index (ARI) was used to quantify the residual cement on the crown surface to determine the mode of bond failure. One-way analysis of variance was used to compare the mean bond strengths between the groups, and the chi-square test was used to assess the predominant site of bond failure. Results: The mean bond strength was highest (2.76±0.07 MPa) and lowest (1.38±0.2 MPa) in the SARC and PXC groups, respectively. The bond strength was significantly different be- tween the groups (P<0.05). Bond failures were observed more frequently at the crown-cement interface in the SARC, RMGIC, and GIC groups and at the band-cement interface in the PXC group. SARC had the lowest ARI score, and PXC had the highest. Conclusion: Self-adhesive resin cement significantly had the highest bond strength and the lowest adhesive remnant score after debanding, followed by resin-modified glass ionomer cement, glass ionomer cement, and zinc polycarboxylate cement, respectively.