In semi-crystalline materials such as PEEK, the mold temperature is an important factor in determining the parameters of the injected product for performance ( Blundell and Osborn, 1983, Cebe et al., 1987, Hamdan and Swallowe, 1996, Invibio, 2004a, Invibio, 2004b). The mold temperature has perhaps a less obvious but often more dominant effect on the properties of the final product. Unfortunately, the non-uniform distribution of mold temperature is a problem that can affect injection molding ( Pawlak and Galeski, 2005, Chen et al., 2006). The injection molding system is one of the most commonly used processing technologies in the plastics industry, and the temperature of the mold is an important factor in determining the final quality of the injected product. Exceptional solvent resistance, low modulus of elasticity, and biocompatibility with bone make this polymer a good candidate to replace the use of metals in the body ( Brillhart and Botsis, 1994, Sobieraj and Rimnac, 2012). PEEK available for medical purposes as granules to be pressed and blank disks to mill. It has increasingly employed in industry and as a biomaterial that can be used for medical purposes ( Kurtz, 2012, Li et al., 2017) and has attracted more interest than any other implantable material for medical devices in the last 20 years ( Rae et al., 2007, Koutouzis et al., 2011, Hahnel et al., 2015, Lee et al., 2017). It is one of the Polyaryletherketones (PAEKs) polymer group family, which is characterized by ultra-high molecular weight polyethylene (UHMWPE) ( Reinhart and Clements, 1993, Merrett et al., 2002, Callister and Rethwisch, 2007). Polyetheretherketone (PEEK) is a semi-crystalline thermoplastic biomaterial with a chemical formula of (-C6H4-O-C6H4-O-C6H4-CO-)n. However, shortcomings in some of their properties have limited their use ( Pfeiffer and Rosenbauer, 2004, Pfeiffer et al., 2005) and it seems that as yet no material fully satisfies the ideal criteria for a denture base.īiocompatibility is a primary requirement in all restorative materials, followed by mechanical and physical properties that guarantee appropriate function and structural permanence over long periods of time ( Anusavice et al., 2013, Teoh et al., 2016). Polysulfone (PSF), nylon and polycarbonate (PC) are suggested for patients who are allergic to acrylic ( Stafford et al., 1986, Tanoue et al., 2005). There has been interested in discovering materials that of very similar to PMMA but have better properties. Although PMMA is a non-metallic denture base material, there is still the possibility of toxic reactions or irritations for the wearer ( Alanko et al., 1996, Kanerva et al., 1997, Lung and Darvell, 2005) and for dental technicians involved in handling and fabrication ( Kanerva et al., 1993, Kiec-Swierczynska, 1996). Some research has proposed the use or development of alternative materials ( Ucar et al., 2012). Nevertheless, many studies have proposed various techniques to improve upon PMMA through the inclusion of other materials ( Bowman and Manley, 1984, Carroll and Von Fraunhofer, 1984, Jagger et al., 1999, Vuorinen et al., 2008, Young, 2010, Ahmed et al., 2016) the addition of metal reinforcement ( Hahnel et al., 2015) fibers ( Uzun et al., 1999, Çağlar et al., 2002, Çökeliler et al., 2007) hydroxyapatite filler or Silica ( Mc Nally et al., 2006, Young, 2010) and modification the chemical properties of the PMMA. Since PMMA is relatively low in cost and easy to use both clinically and in the laboratory, it remains the most popular choice for polymeric removable prosthodontics ( Phoenix, 1996, Rahme et al., 2005). These fractures are due to either flexural fatigue or impact ( Vallittu, 1997, Jagger et al., 1999) which is generally associated with material properties ( Vallittu and Kokkonen, 1997, Sato et al., 2003) and/or framework design integrity ( Rudd and Rudd, 2001a, Rudd and Rudd, 2001b, Rudd and Rudd, 2001c). However, PMMA dentures are susceptible to fracture during use or when dropped onto hard surfaces. The poor performance of these materials led to Polymethylmethacrylate (PMMA) suggested as a replacement ( Little, 1982, Van Noort and Barbour, 2014) and it has now become the most commonly used material for the fabrication of dentures. In dentistry, several materials have been introduced over the last century for dentures such as cellulose products, phenol- formaldehyde (Bakelite), vinyl resins and vulcanite ( Tandon et al., 2010, Van Noort and Barbour, 2014).
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