Temporal effects of restorative pretreatments on biodentine: an in-vitro study

Background: Biodentine is frequently exposed to various surface pretreatments, such as dentin conditioner (DC), glass ionomer liquid (GICL), acid etchant, and adhesives, during pulp capping procedures. However, the impact of these agents on Biodentine's surface microstructure and chemical composition remains underexplored. Objective: This study qualitatively analyzed the effects of DC, type II GICL, acid etchant (AE), Clearfil SE (CFS, a two-step self-etch adhesive), and Single Bond Universal (SBU, a universal adhesive) on the surface microstructure and chemical composition of Biodentine (BD) at 5 min, 12 min, 24 h, and 7 days after manipulation. Materials and methods: BD samples were subjected to the pretreatments and qualitatively analyzed using scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX), micro-Raman spectroscopy, and X-ray diffraction (XRD). Results: SEM revealed distinct surface morphologies depending on the pretreatment and time interval, ranging from homogenous and grainy to smooth and polymer-coated surfaces. EDX showed significant variations in calcium-to-silicon ratios over time. Notably, AE caused pronounced surface disruption up to 24 h, while CFS and SBU resulted in minimal changes. DC, GICL, and DC+GICL did not adversely affect BD's surface microstructure at any time point. XRD and micro-Raman analyses indicated no change in the chemical composition of BD across all groups and time intervals. Conclusion: Surface pretreatments influence BD differently depending on timing. AE compromised surface integrity until 24 h, whereas self-etch and universal adhesives produced only superficial alterations. Delaying aggressive pretreatments until 7 days minimizes disruption.