Nanosilica's Impact on Resin-Based Pulp Capping Material Incorporating Tricalcium Silicate From White Portland Cement

Area of Science:

• Dental Materials Science
• Biomaterials Engineering
• Restorative Dentistry

Background:

• Pulp capping is crucial for preserving pulp vitality in restorative dentistry.
• Mineral Trioxide Aggregate (MTA) is a traditional bioactive material for pulp capping.
• Tricalcium silicate from white Portland cement (TSWPC) is a potential cost-effective alternative to MTA.

Purpose of the Study:

• To investigate the effect of nanosilica (NS) on the bioactivity and mechanical properties of a resin-based TSWPC-ZrO2 formulation for pulp capping.
• To evaluate TSWPC-ZrO2 and TSWPC-SiO2-ZrO2 formulations as potential alternatives for vital pulp therapy.

Main Methods:

• Two formulations, TSWPC-ZrO2 and TSWPC-SiO2-ZrO2, were prepared.
• Mechanical properties (compressive strength, flexural strength, elastic modulus) were tested per ISO 9971-1 and ISO 4049.
• Bioactivity (pH, Ca2+/OH- release, NIH/3T3 cell viability, fibroblast attachment) was monitored over 28 days.

Main Results:

• Nanosilica addition increased 24h compressive strength (105 to 116 MPa) and elastic modulus (7.19 to 7.55 GPa), but decreased flexural strength (83 to 61 MPa).
• Both cements exhibited alkaline conditions (pH 8.0-9.5) and sustained calcium ion release (≤ 31 mg L-1) without significant differences.
• The nanosilica formulation demonstrated superior cell viability at 72h (244% ± 22%) and enhanced fibroblast attachment.

Conclusions:

• Nanosilica accelerates hydration and improves the compressive stiffness of TSWPC-based cements.
• The addition of nanosilica does not compromise the bioactivity of the material.
• The nanosilica-modified TSWPC formulation presents a mechanically robust and cost-effective alternative to MTA for vital pulp therapy.