کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1421219 986399 2013 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Influence of substructure design, veneer application technique, and firing regime on the in vitro performance of molar zirconia crowns
موضوعات مرتبط
مهندسی و علوم پایه مهندسی مواد بیومتریال
پیش نمایش صفحه اول مقاله
Influence of substructure design, veneer application technique, and firing regime on the in vitro performance of molar zirconia crowns
چکیده انگلیسی

ObjectivesThe aim of this in vitro study was to evaluate the influence of substructure design, veneer application technique, and firing regime on the failure and fracture resistance of molar zirconia crowns.MethodsSix groups (n = 8/group) of zirconia crowns were fabricated in simple core (SC) or anatomically reduced (AR) design, veneered with different feldspathic or glass ceramic materials, and defined according to the application technique and firing regime (LT: layering technique; LT_L: LT with long-term cooling; PT: press technique; DV: digital veneering technique). The following groups were investigated: SCLT, ARLT, SCLT_L, SCPT, ARPT, ARDV. Crowns were adhesively bonded to polymethylmethacrylate abutment teeth and subjected to thermal cycling (TC: 2 × 3000 × 5°/55°) and mechanical loading (ML: 1.2 × 106; 50 N; 1.6 Hz) in a chewing simulator with metal-ceramic molar crowns as antagonists. Failures were monitored and fracture resistance determined after aging. Data were statistically analyzed (one-way analysis of variance, ANOVA; post hoc Bonferroni, α = 0.05). Crowns were subjected to scanning electron microscopy for fractographic failure analysis.ResultsFailures (chipping, cracks) during TCML were observed in groups SCLT (2×), ARDV (2×) and SCLT_L (1×). Defect sizes varied between 3.5 mm (SCLT: crack) and 30.0 mm2 (SCLT_L: chipping). Mean (SD) fracture forces ranged between 1529.0 (405.2) N for SCPT and 2372.3 (351.8) N for ARDV.SignificanceThe failure frequency of veneered zirconia crowns could be reduced by using anatomically reduced substructures, the press veneering technique, and an adapted cooling protocol. Fracture resistance increased with use of anatomically reduced substructures and the digital veneering technique.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Dental Materials - Volume 29, Issue 7, July 2013, Pages e113–e121
نویسندگان
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