Comparative Evaluation of the Effect of Different Desensitising Methods on the Retention of Crowns Cemented with Resin Modified GIC:An In-Vitro Study

Introductions: This in vitro study aimed to evaluate and compare the effect of three different desensitizing methods— Admira Protect, dentin bonding agent (Tetric N Bond), and diode laser—on the retention of porcelain-fused-to-metal (PFM) crowns cemented with resin-modified glass ionomer cement (RMGIC). Methods: Forty extracted, non-carious human premolars were prepared for full-coverage crowns and divided into four groups (n = 10): Group I (Control, no desensitizer), Group II (Admira Protect), Group III (Dentin bonding agent), and Group IV (Diode laser). Standardized tooth preparations were performed and PFM crowns were fabricated and cemented using RMGIC (RelyX Luting 2, 3M ESPE). The crowns were subjected to tensile dislodgement forces using a universal testing machine, and peak dislodgement loads were recorded. Data were analyzed using the Kruskal-Wallis test followed by post hoc comparisons. Results: Significant differences in crown retention were observed among the groups (p < 0.05). The control group exhibited the highest mean retention value (27.835 ± 0.790 kgf), followed by the diode laser group (25.607 ±1.054kgf), dentin bonding agent group (22.101 ± 0.871 kgf), and Admira Protect group (20.826 ± 0.862 kgf). Post hoc analysis revealed statistically significant differences between most groups, indicating that desensitizing agents can influence cement retention. Conclusions: Among the tested methods, diode laser treatment showed the least compromise in retention and can be considered a viable desensitizing option before cementation with RMGIC. Admira Protect significantly reduced retention values, possibly due to interference with the bonding mechanism of the cement. These findings highlight the importance of choosing appropriate desensitizing agents to balance sensitivity management and prosthesis retention.