Comparative Evaluation of Mechanical Properties of Dental Nanomaterials

Abstract

This study examines the properties of nanobased dental restorative materials with nanoindentation method in a precise, repeatable, and comparable way. Microhybrid and nanohybrid composites, conventional glass ionomer materials, and light cured nanoionomer materials were utilised for the study. Specimen discs (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M1"><mml:mi>r</mml:mi><mml:mo>=</mml:mo><mml:mn fontstyle="italic">10</mml:mn></mml:math> mm,<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M2"><mml:mi>h</mml:mi><mml:mo>=</mml:mo></mml:math>2 mm) were prepared to test the hardness, modulus of elasticity, yield strength, and fracture toughness values for each sample in a nanoindentation device with an atomic force microscopy add-on (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M3"><mml:mi>n</mml:mi><mml:mo>=</mml:mo><mml:mn fontstyle="italic">25</mml:mn></mml:math>). Comparative analyses were performed by one-way ANOVA and post hoc Tukey tests. The hardness and modulus of elasticity values of nanocomposite were higher (2.58 GPa and 32.86 GPa, resp.) than those of other dental materials. Although glass ionomer exhibited a hardness that was similar to a nanoionomer (0.81 versus 0.87 GPa), glass ionomer had the lowest fracture toughness value (<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M4"><mml:msub><mml:mrow><mml:mi>K</mml:mi></mml:mrow><mml:mrow><mml:mi>c</mml:mi></mml:mrow></mml:msub><mml:mo>=</mml:mo><mml:mn fontstyle="italic">0.83</mml:mn></mml:math> MPa/mm 0.5 ). The mechanical properties of resin composites improve with additional nanoscale fillers, unlike the glass ionomer material.