The harnessing of the waste arising from Y-TZP dental ceramics manufactured by CAD/CAM to be used as alternative dental materials

Current prospect of dental zirconia recycling: A scoping review

“…In an included study published in Chinese [6], the effects of two particle sizes (50 μm<particle diameter≤125 μm and particle diameter≤50 μm) of recycled zirconia powder and the presintering heating rate (2°C, 5°C, and 8°C/min) on the performance of dental recycled zirconia were examined. 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].…”

“…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].…”

“…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].…”

“…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]. This also renders the preparation parameters of commercial zirconia unsuitable for recycled zirconia [6,12].…”