Synthesis of PMMA/ZnO nanoparticles composite used for resin teeth

Abstract

Wear resistance is one of the most important physical properties of the artificial teeth used in acrylic dentures. The goal of this research was to synthesize a new composite material made of matrix Poly-(methyl methacrylate)-PMMA with different percentages (2 % and 3 % of volume fractions) of zinc-oxide nanoparticles (ZnO NPs) as reinforcing elements, to improve its mechanical properties. The dynamic mechanical behaviour of this composite was studied through the DMA method in comparison to the pure PMMA supported by the characterization of their microstructures. Then the wear resistance was analysed on the samples, which were prepared in the form of teeth. In this context their vertical height loss was measured after 100,000 chewing cycles on a chewing simulator, before and after the artificial thermal ageing. Investigations showed that the PMMA/ZnO NP composites dampened the vibrations better than the pure PMMA, which could be assigned to the homogenous distribution of ZnO NPs in the PMMA matrix. It was found that the mean vertical height loss for the pure PMMA teeth was significantly higher (more than 4 times) compared to composite teeth made with ZnO NPs. Introducing the thermal artificial ageing led to the finding that there was no effect on the height loss by the composite material with 3 % of volume fractions of ZnO NPs. Based on this it was concluded that PMMA/ZnO NPs composites showed improved in-vitro wear resistance compared to acrylic-resin denture teeth, so this new composite material should be preferred when occlusal stability is considered to be of high priority. Keywords: poly-(methyl methacrylate)-PMMA, zinc-oxide nanoparticles, composite, resin teeth Odpornost proti obrabi je ena izmed najbolj pomembnih fizikalnih lastnosti umetnih zob pri akrilnih protezah. Cilj te raziskave je bil sintetiziranje novega kompozitnega materiala, izdelanega iz matrice poli-(metil meta akrilata)-PMMA z razli~nimi volumskimi odstotki (2 % in 3 %) nanodelcev cinkovega oksida (ZnO NPs), uporabljenimi kot oja~itveni element za izbolj{anje mehanskih lastnosti materiala. Dinami~no mehansko obna{anje teh kompozitov smo raziskali z metodo DMA v primerjavi s istim PMMA, ter s karakterizacijo njihovih mikrostruktur. Nato je bila analizirana odpornost proti obrabi na vzorcih, ki so bili pripravljeni v obliki zob. Izmerjena je bila njihova navpi~na izguba vi{ine po 100.000`ve~ilnih ciklih na`ve~ilnem simulatorju, pred in po umetnem toplotnem staranju. Preiskave so pokazale, da so PMMA/ZnO NPs kompoziti bolje bla`ili vibracije kot~isti PMMA, kar lahko pripi{emo homogeni porazdelitvi ZnO NPs v PMMA matrici. Ugotovili smo, da je bila povpre~na navpi~na izguba vi{ina za~isti PMMA zob znatno vi{ja (ve~kot 4×) v primerjavi s kompozitnimi zobmi z ZnO NPs. Umetno toplotno staranje ni imelo u~inka na izgubo navpi~ne vi{ine zoba iz kompozitnega materiala s 3 volumskimi % ZnO NPs. Na podlagi tega smo sklenili, da imajo kompoziti PMMA/ZnO NPs izbolj{ano in vitro odpornost proti obrabi, v primerjavi z zobno protezo iz akrilne smole, zato n...

Microstructure Characterisation and Identification of the Mechanical and Functional Properties of a New PMMA-ZnO Composite

“…Those results are also followed by increased E modulus and damping and reduced level of cross-linking, which leads to this material being more friendly to oral mucosa due to vibration damping. This phenomenon consequently resulted in fewer residual monomers and is in concordance with some previous research [25,31,39]. Consequently, PMMA/ZnO NPs present dentistry and patients with a new option for PMMA replacement because it is expected, due to its higher density, to have a reduced risk of allergic reactions; specifically, allergic reactions are closely connected to the presentation of residual monomers and porosity inside of polymer materials [22], which could lead to lower mechanical properties too.…”

“…The ZnO NPs are shown as white particles mixed with PMMA powder in Figure 1, where the image was taken on a Sirion electron microscope 400 NC (Field Electron and Ion Company-FEI, Hillsboro, OR, USA). For the synthesis of the new composite based on PMMA, the use of 2 wt.% ZnO NPs was chosen, according to our previous experience and based on the literature [25].…”

“…The ZnO NPs are shown as white particles mixed with PMMA powder in Figure 1, where the image was taken on a Sirion electron microscope 400 NC (Field Electron and Ion Company-FEI, Hillsboro, OR, USA). For the synthesis of the new composite based on PMMA, the use of 2 wt.% ZnO NPs was chosen, according to our previous experience and based on the literature [25]. The PMMA matrix (PMMA powder with benzoyl-peroxide, pigments and the liquid methylmethacrylate HQ 60, ethylene glycoldimethacrylate, methylmethacrylate composite) was purchased from Galenika (Belgrade, Serbia).…”

“…Based on our previous research [25], it was determined that the percentages of ZnO NPs in the PMMA matrix of 2 vol.% and 3 vol.% are sufficient to improve the physical and mechanical characteristics of the newly obtained PMMA/ZnO NPs composite.…”

Mechanical and Physicochemical Properties of Newly Formed ZnO-PMMA Nanocomposites for Denture Bases

“…The antibacterial and antifungal activity of ZnO-NPs was the major rationale for commencing in 2014 the research on dentures modified by ZnO-NPs, which are supposed to ultimately be characterized by antifungal properties [ 12 , 13 ]. At present, this issue has gained a growing interest among the scientist around the world and has already been investigated by several research groups [ 14 , 15 , 16 , 17 , 18 , 19 , 20 ].…”