The current work focuses on the modification of dental nanocomposites using nanosized fillers. To determine the impact on the wear resistance, flexural strength, compressive strength, and hardness qualities of the dental nanocomposites, three types of nanoparticles—silica (SiO₂), zircon (ZrO₂), and hydroxyapatite (H.A.: Ca₅(PO₄)₃OH)—are combined with a standard matrix of dental resin. This study’s objective is to create dental nanocomposites using the nanoparticles above as fillers in Bis-GMA with unsaturated monomers, urethanedimethacrylate (UDMA), methylmethacrylate (MMA), methacrylic acid (MAA), and bisphenol A dimethacrylate in the presence of 1,6-hexanediol methacrylate (HDODA) as a crosslinking agent. To start the copolymerization of matrix resins, camphor quinone (C.Q.) of 0.5 wt.% and 2-(dimethyl amino) ethyl methacrylate (DMAEMA) of 0.5 wt.% are utilized as photoinitiation systems. These nanocomposites have the potential for posterior restorative applications. Treatment of the Nano (SiO₂, ZrO₂, Hydroxyapitate (HA)) particles was carried out with a silane coupling agent, 3-(methacryloyloxy)propyltrimethoxysilane (MPTMS), to improve bonding between the Nano particles and resin matrix, and reduce agglomeration of the Nano SiO₂,ZrO₂, Hydroxyapitate (HA)). Characterization of products was carried out using scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR). SEM images showed the adhesion between the resin matrix and the Nano (SiO₂, ZrO₂, Hydroxyapitate (HA)), and particle size distribution in addition to the particle agglomeration that is related to the treated Nanofillers in Nanocomposites. FTIR was used to show the qualitative composition of untreated Nanofillers and treated Nanofillers. The three types of nanoparticles (SiO₂, ZrO₂, and H.A. with an average size between 10 and 30 nm) were further functionalized with 3-(methacryloyloxy)propyltrimethoxysilane (MPTMS), a silane coupling agent, to improve compatibility between the phases. Using scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy, the compatibility between the phases and the morphology was determined (FTIR). The adhesion between the resin matrix and the particle, whether homogeneous or heterogeneous nanocomposites, are formed. SEM saw the effect of salinization. FTIR was employed to communicate qualitative information regarding the impact of salinization. flexural strength, and compressive strength, of nanocomposites made with untreated nanoparticles or nanoparticles treated with 2.5 wt.% MPTMS were significantly greater than those made with nanoparticles treated with 1.5 or 3.5 wt.% MPTMS. The nanocomposites containing 10 wt.% SiO₂ had more flexural strength, compressive strength than those containing other nanofillers (ZrO₂ and hydroxyapatite (H.A.). Surprisingly, this development was observed at a significantly lower nanosized filler concentration. Utilizing the TGA and DSC methodologies, physicochemical parameters such as solubility (S.L.), water sorption (W.S.), and volumetric shrinkage (VS) were also investigated. Additionally, the thermal stability of the entire dental nanocomposites is evaluated.

Keywords: Nanoparticles fillers, Coupling agent MPTMS, flexural strength ,Compressive strength , Light curing.