180 - Oxymetazoline as a Pulpotomy Medicament: Effects on MTA Structure-Function

Abstract:

Purpose: This study evaluated the effect of a pulpotomy hemostatic medicament, 0.05% oxymetazoline solution (OXY), on the morphology, elemental composition, and mechanical properties of calcium silicates.

Methods: In this in vitro study, calcium silicate (NeoPutty) material was placed in resin molds and immersed in 30μl test samples (n=5) containing: distilled water (DW), 17% EDTA, OXY (nasal spray solution, Afrin), and 5.25% Sodium Hypochlorite (NaOCl) for 1 min. Treated samples were incubated in artificial saliva (AS) for 7 days at 37°C. SEM-EDX was used to analyze the microstructure and elemental composition of hydrated calcium silicate. Mechanical properties were assessed using Hysitron TriboIndenter. Microleakage was evaluated in occlusally prepped permanent molars (4 mm × 3 mm; n = 8) after 6 months of incubation using 2% methylene blue dye.

Results: SEM revealed that DW and OXY-treated calcium silicate exhibited larger amorphous, granular-globular deposits with distinct plate-like crystals. EDTA and NaOCl-treated samples showed roughened surfaces with porosities and leaching of white hydration products, indicating disruption of the hydration matrix. EDX for all groups primarily displayed oxygen, calcium, tantalum, silica, aluminum. EDX showed significant difference in Ca (Wt%) between EDTA and and NaOCl-treated samples (P < .05). Nanoindentation and microleakage testing are ongoing to further characterize the mechanical integrity and sealing potential of treated calcium silicate.

Conclusion: The results of this study suggest that when an OXY-based nasal solution is applied directly to pulp tissue to induce hemostasis, residual amounts will preserve the surface morphology of calcium silicates when used as a pulp capping material.

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