Study of the Sintering Dental Ceramic Waste from ZrO₂-Y₂O₃ System

Abstract

During processing of zirconia blocks, where they are used for different dental implants type, most of the loosed material as a powder is subsequently discarded. Besides damage to the environment, waste of material results in financial losses, resulting in higher final cost of treatment. The yttria stabilized zirconia (Y-TZP) has a variety of applications due to it is combination of high strength and fracture toughness. The objective was to reuse zirconia waste analyzing the effects of sintering temperature. The starting materials used in this study were two different powders of ceramic system ZrO3-Y2O3: commercial zirconia nanoparticle and microparticle zirconia waste. The raw material was shaped by uniaxial and isostatic pressing and then sintered at 1500, 1550 and 1600 ° C over 1 hour. The X-ray diffraction (XRD) and dilatometry were used to powder characterization. After sintering density / porosity, flexural strength, and scanning electron microscopy (SEM) were realized .The waste showed similar values of density, and grain size to commercial material studied, confirming that it can be reused.

Current prospect of dental zirconia recycling: A scoping review

“…Compared with coarse particles, recycled zirconia powder with fine particles effectively enhanced the physical and mechanical properties of recycled zirconia, which is consistent with the results of another study [12]. Recycled zirconia is typically formed through uniaxial or cold isostatic pressing, and the latter method yields denser recycled zirconia [11,13]. The flexural strength of zirconia showed no mechanical improvement with the incorporation of zirconia residue powder.…”

“…3). The predominant zirconia material used for recycling is 3 mol% Y-TZP (3Y-TZP) [4][5][6][11][12][13][25][26][27][28][29][30][31][32][33]. Among the included studies, one was published in Chinese [6], while the others were published in English.…”

“…Ten studies focused on examining the direct recycling of dental zirconia residue powder [4,[11][12][13]25,26,30,31,33,34]. Six of these studies involved pressing the recycled zirconia powder into green zirconia bodies, which were then sintered [4,[11][12][13]25,30]. Two studies utilized recycled zirconia powder as reinforcing fillers in polymeth-ylmethacrylate (PMMA) [33,34].…”

“…Similarly, previous studies on recycling dental zirconia residuals have shown that recycled zirconia obtained through various recycling approaches can exhibit different properties [6,[11][12][13]. For instance, recycled zirconia treated with cold isostatic pressing exhibits superior density and bending strength compared with zirconia prepared through uniaxial molding [11,13]. Compared with the initial zirconia powder, recycled zirconia powder has a larger particle size and an irregular shape, which can negatively affect its molding and sintering kinetics [4,6].…”

“…These diverse methodologies employed contribute to the large differences between commercial products [10]. Similarly, previous studies on recycling dental zirconia residuals have shown that recycled zirconia obtained through various recycling approaches can exhibit different properties [6,[11][12][13]. For instance, recycled zirconia treated with cold isostatic pressing exhibits superior density and bending strength compared with zirconia prepared through uniaxial molding [11,13].…”