Bone substitute nanomaterials for enhancing the apatite-forming capacity of dental repair material
European Journal of Prosthodontics and Restorative Dentistry (2026) 34(2), 91–98
KeywordsApatite-forming ability, Bioactivity, Surface mineralization, Ca/P ratio, Surface chemical reactivity, Dental cement.
AuthorABSTRACTObjective: To analyse the apatite-forming ability of mineral trioxide aggregate (MTA Angelus) modified with nano carbonated hydroxyapatite (nCHAp) as a bioactive endodontic biomaterial. Methods: Disc specimens (10.0 ± 0.1 mm diameter; 2.0 ± 0.1 mm thickness) were made-up from unmodified MTA (control) and MTA hold 2, 3, and 4 wt%nCHAp (n=12/group). After setting for 24 h at 37 °C and relative humidity, six specimens per group were immersed in 20 mL sterile phosphate-buffered saline (PBS, pH 7.4) at 37 °C for 21 days with PBS renewal every 3 days; the remaining six were stored dry. Surface mineralization was measured by fieldemission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDX; five spots/specimen) with Ca/P ratio calculation, and Xray diffraction (XRD) for phase finding. Statistical analysis was performed using ANOVA/Tukey tests (α = 0.05). Results: PBS exposure evoked calcium-phosphate deposition on all immersed specimens. Unmodified MTA showed porous spherical Ca–P aggregates agreeable with amorphous calcium phosphate; phosphorus emerged (13.60 wt%) and Ca/P was 2.49, indicating calcium-rich, immature surface deposits. Adding nCHAp boosted mineralization, and the effect got stronger with higher concentrations. At 2 wt%, it created an early layer with a change into flat, plate-like crystals. When the concentration went up to 3–4 wt%, it formed continuous nano-sized apatite layers with needle and plate shapes, along with rosette-like clusters. After soaking, the calcium-to-phosphorus ratios dropped a bit—down to around 1.80 for 2%, 1.76 for 3%, and 1.70 for 4%—getting closer to normally seen in natural bone. XRD results showed clear signs of hydroxyapatite/carbonated hydroxyapatite reflections with decreased silicate/portlandite intensities after immersion. Conclusions: Adding 2–4 wt% nCHAp speeds up the natural-like apatite formation on MTA, boosting its chances for regenerative endodontic repair and strengthening the mineral layer where dentin meets the material. Clinical Relevance: Improving the bioactivity helps the seal become stronger and supports the hard tissue in healing better. This could make MTA last longer and perform more reliably during root canal treatments.
INTRODUCTIONIn recent years, there’s been some exciting advancement in dental materials. New fillings and products that help regrow bone. These advances are shifting how dentists treat patients and making outcomes better1. These days, there’s a focus on bioactive material because they interact with biological tissues when they touch cells. They aid natural repair and regeneration processes, which ultimately lead to better oral health2. Calcium hydroxide, the first endodontic material known for its ability to encourage the formation of a dentinal bridge over exposed pulp tissue3. Over time, newer materials like mineral trioxide aggregate (MTA) and similar calcium silicate cements were developed. These are basically portland cement mixed with bismuth oxide to make them visible on X-rays. These hydraulic bioceramics have become popular for use in procedures like vital pulp therapy, repairing perforations, and other dental repairs4. Their bioactivity comes from releasing calcium ions, which react with phosphate in the body fluids, this creates hydroxyapatite crystals on the surface of the material to support tissue repair5. •••••••••••••••••••••••••••••••• ejprd.org - Published by Riset Publishing Services LLC
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