Effect of extrinsic pigmentation and multiple firing cycles on the properties of a zirconia-containing lithium silicate ceramic.

Purpose: To assess the impact of staining and multiple firings on the mechanical, optical, and surface characteristics of zirconia-containing lithium silicate ceramics (ZLS).

Materials And Methods: Ninety ZLS discs (Suprinity, VITA Zahnfabrick) were divided according to the "Number of firings" protocol: Ctr-control, no characterization; SC-single firing cycle (for characterization, crystallization and staining simultaneously); and DC-double firing cycle (crystallization firing cycle was performed separately from the staining firing). Extrinsic pigmentation was performed to replicate the characterization of a monolithic restoration.

Effect of different surface treatments on the micro tensile bond strength to dentin, biaxial flexural strength and roughness of CAD/CAM resin composite and polymer infiltrated ceramic.

Objectives: To evaluate the biaxial flexural strength (BFS), surface roughness (Ra) and micro tensile bond strength (μTBS) of two CAD/CAM materials after different surface treatments.

Materials And Methods: For μTBS, 64 human molars were used and 32 blocks of resin composite (RC-Lava Ultimate) and polymer-infiltrated ceramic (PIC -Vita Enamic). The blocks and teeth were distributed into 16 groups according to the factors "surface treatment" (HF: 10% hydrofluoric acid; APA: AlO sandblasting; SC: silicate-AlO sandblasting; MEP: Monobond Etch and Prime) and "thermal cycling" (TC).

Effect of different surface treatments on the biaxial flexure strength, Weibull characteristics, roughness, and surface topography of bonded CAD/CAM silica-based ceramics.

Objective: To investigate the influence of different surface treatments on biaxial flexure strength, roughness, and surface topography of lithium silicate/disilicate-based ceramics.

Methods: 225 discs (∅: 12 mm; 1.2 mm - ISO 6872) were made from three ceramics: IPS e.

Can different etching protocols change the properties of a hybrid ceramic?

The aim of this study was to evaluate the effects of different concentrations of hydrofluoric acid (HF) and etching times on the flexural strength, roughness, wettability, and type of failure of a hybrid ceramic (VITA ENAMIC). Blocks of the ceramic material were made according to the norms of International Organization for Standardization standard 6872:2015 and randomly divided into 7 groups (n = 13): control (no treatment); surface etching with 5% HF for 30 (HF5-30), 60 (HF5-60), or 90 (HF5-90) seconds; and surface etching with 10% HF for 30 (HF10-30), 60 (HF10-60), or 90 (HF10-90) seconds. The adhesive surface of 10 specimens in each group was cemented with dual-curing resin cement.

Effect of repeated firings and staining on the mechanical behavior and composition of lithium disilicate.

Objective: To evaluate the composition, flexural strength and fatigue behaviour of lithium disilicate ceramic (LD) after repeated firings and different staining techniques.

Methods: LD discs were fabricated and divided according to number of firing cycles and staining technique: CO - control, discs were crystallized (850°C/10min); SC - single-step characterization - crystallization and staining (applied with a thin brush) were performed in a single step with one firing cycle (850°C/10min); and DC - double-step characterization - crystallization firing cycle was performed first (850°C/10min), followed by staining firing cycle (770°C/90s). Specimens were fired two, four or six times (one crystallization firing cycle and one, three or five staining firing cycles), resulting into 9 groups (n=30): COII, COIV, COVI, SCII, SCIV, SCVI, DCII, DCIV and DCVI.

Effect of staining and repeated firing on the surface and optical properties of lithium disilicate.

Objective: Evaluate the effect of staining and repeated firings on color, translucency and surface proprieties of CAD/CAM lithium disilicate (LD).

Material And Methods: One hundred eighty LD discs were made (ISO 6872) and distributed in different groups (n = 20): control (CO)-no treatment; single-step characterization (SC)-crystallization and staining fired together; and double step characterization (DC)-crystallization and then staining. The samples were submitted to two, four, or six firings, resulting in nine groups: COII, COIV, COVI, SCII, SCIV, SCVI, DCII, DCIV, and DCVI.

Effect of extrinsic pigmentation and surface treatments on biaxial flexure strength after cyclic loading of a translucent ZrO ceramic.

Objective: To evaluate the influence of extrinsic pigmentation on the biaxial flexural strength and surface topographic of translucent Y-TZP (InCoris TZI - Sirona - USA) subjected to several surface treatments.

Methods: Sintered zirconia discs-shaped specimens (n=120) (ø:12mm; thickness:1.2mm; ISO 6872) were prepared and divided (n=15) according to various factors: "extrinsic pigmentation" (n: without; p: with) and "surface treatments" (C: control - as sintered; A: abraded with silica-coated alumina particles (30μm); G: glazed with a thin film of low-fusing porcelain glaze; GH: glazed and etched with 10% hydrofluoridric acid for 60s.

Effect of different loading pistons on stress distribution of a CAD/CAM silica-based ceramic: CAD-FEA modeling and fatigue survival analysis.

Purpose: This study evaluated the effect of different loading pistons, made of various materials and with different elastic moduli acting as antagonist material, on stress distribution and fatigue behavior of a CAD/CAM silica-based ceramic.

Materials And Methods: Discs of CAD/CAM made silica-based ceramic (N = 60) (VITA MARK II) were divided into six groups (n = 10 per group), according to the test method (M: Monotonic; F: Fatigue) and the antagonist piston material (T: Tungsten; S: Steel; G: Epoxy resin). FT, FS and FG combinations were submitted to mechanical cycling (2 × 10 cycles, 4 Hz, 45 N).

Can low-fusing glass application affect the marginal misfit and bond strength of Y-TZP crowns?

To evaluate the effect of different surface treatments on the marginal misfit and retentive strength between Y-TZP crowns and an epoxy resin. Forty (40) epoxy resin (G10) abutments (height: 5mm, conicity: 60, finish line: large chamfer) with equal dimensions were milled and included in polyurethane to simulate the periodontal ligament. Next, 40 Y-TZP crowns (thickness: 1mm) were milled (Cerec in Lab) and randomly divided into four groups (n=10) according to the surface treatment: GS(glaze spray), GP(glaze powder/liquid), P(zirconia primer) and RS(tribochemical silica coating).

Effect of fatigue protocols on flexural strength of lithium disilicate bars with clamped-ends.

The aim of this study was compare the effect of two in vitro ageing protocols to intraoral aging on the flexural strength of a lithium disilicate (LD) ceramic bars with clamped ends. After polishing and crystallization, the both ends of the bars were cemented to a metallic device and subjected to mechanical cycling, thermomechanical cycling, or intraoral ageing. Ten volunteers used an intraoral device - similar to an occlusal splint with a balanced contact condition on the occlusal surface of the ceramic bar - during 8 h night time / 30 days.