کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5640551 1585469 2017 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Translucent zirconia in the ceramic scenario for monolithic restorations: A flexural strength and translucency comparison test
ترجمه فارسی عنوان
زیرکونیا شفاف در سناریوی سرامیکی برای ترمیم یکپارچه: یک آزمون مقایسه قدرت و خمش
موضوعات مرتبط
علوم پزشکی و سلامت پزشکی و دندانپزشکی دندانپزشکی، جراحی دهان و پزشکی
چکیده انگلیسی

ObjectiveTo compare three different compositions of Yttria-Tetragonal Zirconia Polycrystal (Y-TZP) ceramic and a lithium disilicate ceramic in terms of flexural strength and translucency.MethodsThree zirconia materials of different composition and translucency, Aadva ST [ST], Aadva EI [EI] and Aadva NT [NT](GC Tech, Leuven, Belgium) were cut with a slow speed diamond saw into beams and tabs in order to obtain, after sintering, dimensions of 1.2 × 4.0 × 15.0 mm and 15.0 × 15.0 × 1.0 mm respectively. Blocks of IPS e.max CAD LT were cut and crystallized in the same shapes and dimensions and used as a reference group [LD]. Beams (n = 15) were tested in a universal testing machine for three-point bending strength. Critical fracture load was recorded in N, flexural strength (σ in MPa), Weibull modulus (m) and Weibull characteristic strength (σ0 in MPa) were then calculated. Tabs (n = 10) were measured with a spectrophotometer equipped with an integrating sphere. Contrast Ratios were calculated as CR = Yb/Yw. SEM of thermally etched samples coupled with lineal line analysis (n = 6) was used to measure the tested zirconia grain size. Data were statistically analyzed.ResultsDifferences in translucency, flexural strength and grain size were found to be statistically significant. CR increased and flexural strength decreased in the following order ST(σ 1215 ± 190 MPa, CR 0.74 ± 0.01) > EI(σ 983 ± 182 MPa, CR 0.69 ± 0.01) > NT(σ 539 ± 66 MPa, CR 0.65 ± 0.01) > LD (σ 377 ± 39 Mpa, CR 0.56 ± 0.02). The average grain size was different for the three zirconia samples with NT(558 ± 38 nm) > ST(445 ± 34 nm) > EI(284 ± 11 nm).ConclusionsThe zirconia composition heavily influenced both the flexural strength and the translucency. Different percentages of Yittria and Alumina result in new materials with intermediate properties in between the conventional zirconia and lithium disilicate. Clinical indications for Zirconia Aadva NT should be limited up to three-unit span bridges.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Dentistry - Volume 60, May 2017, Pages 70-76
نویسندگان
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