Effect of Immediate Dentin Sealing on the Bond Strength of Resin Cement to Diabetic Dentin

This in vitro study evaluated the shear bond strength (SBS) of resin cement to diabetic and non-diabetic dentin following immediate dentin sealing (IDS) or conventional bonding without IDS, under two cementation protocols: immediate cementation (IC) and one-week delayed cementation (DC) after provisionalization. From a biomimetic perspective, IDS represents a tissue-preserving adhesive approach aimed at maintaining a stable resin–dentin interface; however, systemic conditions such as diabetes mellitus may alter the dentin substrate and affect adhesive performance. A total of 120 extracted human molars were divided into diabetic (n = 60) and non-diabetic (n = 60) groups, each further categorized by adhesive strategy (IDS or without IDS) and cementation protocol (IC or DC). IDS was performed using a three-step etch-and-rinse adhesive system, and cementation was completed with a dual-cure resin cement. Differences in SBS were observed between diabetic and non-diabetic dentin, adhesive strategies, and cementation protocols. Across all conditions, IDS-treated specimens exhibited higher bond strength than those without IDS, and DC resulted in lower SBS than IC in both adhesive strategies. In all subgroups, non-diabetic dentin showed greater SBS than diabetic dentin. The highest SBS was recorded in the non-diabetic IDS-IC group, whereas the lowest was observed in the diabetic without IDS–DC group. Under the tested laboratory conditions, IDS-treated groups showed higher SBS than the corresponding groups without IDS, while the immediate cementation protocol resulted in higher SBS than the delayed cementation protocol.