In this study, novel composites materials composed of polymethyl methacrylate (PMMA) reinforced ZrO2-Al2O3-SiO2 filler system were developed. Zirconia-alumina-silica filler system were synthesized through sol-gel technique. Chitosan and trimethoxypropilsilane (TMPS) were used to modify the composites system. The resulting composites material were characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD) and hardness test. SEM images displayed the composites particles in nanometer size with minor agglomeration. The XRD results revealed the presence of cubic and tetragonal phase of zirconia and also monoclinic silica phases in the composites system. These crystallographic characteristic could affect the mechanical properties of the composites. The hardness value for un-modified composites was 15.27 ± 0.25 VHN and for TMPS 19.43 ± 1.89 VHN and chitosan modification 18.75 ± 2.05 VHN, respectively. Therefore, these novel composites materials composed of PMMA reinforced filler system of zirconia-alumina-silica would provide the potential to apply in dental technology.

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Introduction: A dental post is a restoration to preserve the remaining tooth structure thus can be functioned normally. Many researchers suggested a fiber dental post due to its biomechanical properties that are similar to dentin structure. This study aims to analyse the flexural properties of electrospun polymethyl methacrylate microfiber-reinforced BisGMA for dental post prefabrication. Methods: The sample used was following the ADA guideline, as well as for the number of samples. The sample size was 25×2×2mm, which is close to the average dental post size. PMMA microfibers were prepared by dissolving heat cure PMMA powder with 99% acetone, then electrospinning with a rotary collector. Acquired PMMA microfibers were immersed into the resin matrix containing BisGMA, camphorquinone, and 2-dimethylaminoethyl methacrylate (DMAEMA) as a monomer, initiator, and co-initiator, respectively, to prepare the dental posts. Results: PMMA microfibers structure and surface fracture of dental posts were confirmed by Scanning Electron Microscopy (SEM). PMMA microfibers show unaligned fiber morphology with an approximate diameter size of 1-5 µm.  A universal testing machine was used to measure the dental post's flexural properties (flexural strength and flexural modulus). Dental posts with PMMA fibers showed higher flexural strength (83.5 ± 10.7 MPa) compared to the dental post without PMMA fibers (61.7 ± 3.03 MPa) with a p-value <0.05. On the other hand, PMMA fibers' addition did not significantly increase the dental post's flexural modulus. Conclusion: The PMMA microfibers can intimately adhere to the BisGMA mixture as the resin matrix. Therefore, the PMMA microfiber significantly improves the flexural strength of the BisGMA for dental post prefabrication.