Determination of the Effect of Rod‐Shaped Lithium Disilicate Particles on the Mechanical and Physical Properties of Dental Composites

ABSTRACT This study examined the potential use of lithium disilicate (LS) particles to reinforce dental composites and improve their mechanical properties. The present study is original in determining the effects of LS powders on dental composite properties. High‐aspect‐ratio LS powders were successfully synthesized hydrothermally. LS particles were added to the composite at 0, 2.5, 5, 10, and 15 wt%. Amorphous silica was added to bring the total reinforcement to 50 wt% for all composites. The resulting composites were tested for flexural strength, flexural modulus, micro‐hardness, water sorption, solubility, polymerization shrinkage, and curing depth. LS powders improved the mechanical properties of composites at low reinforcement ratios. The LS‐5 sample, which contained 5% LS by weight, produced the best results. The flexural strength and modulus of the LS‐5 increased by about 15% and 90%, respectively. Additionally, adding LS to this sample reduced polymerization shrinkage by about 50%. However, at higher reinforcement levels, mechanical properties decreased due to agglomeration. Overall, the results indicate that adding small amounts of high‐aspect‐ratio LS powders as a secondary reinforcement improves the mechanical properties of dental composites.