Impact of High-Speed Sintering of Three-Unit 3Y-TZP and 4Y-TZP Fixed Dental Prostheses on Fracture Load With and Without Artificial Aging.

Purpose: To investigate the impact of high-speed sintering and artificial aging on the fracture load of three-unit zirconia fixed dental prostheses (FDPs).

Materials And Methods: Three-unit FDPs manufactured from 3Y-TZP (Ceramill Zolid, Amann Girrbach) and 4Y-TZP (Ceramill Zolid HT+, Amann Girrbach; N = 128, n = 64/group) were sintered at 1,580°C (high-speed sintering) or at 1,450°C (control group; n = 32/subgroup). Specimens were bonded to steel abutment models using Multilink Automix (Ivoclar Vivadent), and fracture load was examined without (n = 16/subgroup) and with artificial aging (6,000 thermocycles [5°C/55°C] and 1,200,000 chewing cycles [50 N]; n = 16/subgroup).

Impact of high-speed sintering, layer thickness and artificial aging on the fracture load and two-body wear of zirconia crowns.

Objective: To investigate the impact of high-speed sintering, layer thickness and artificial aging in a chewing simulator on the fracture load (FL) and two-body wear (2BW) of 4Y-TZP crowns.

Methods: 4Y-TZP crowns (Ceramill Zolid HT+, Amann Girrbach AG) in three different layer thicknesses (0.5, 1.

Translucency, flexural strength, fracture toughness, fracture load of 3-unit FDPs, Martens hardness parameter and grain size of 3Y-TZP materials.

Objective: This investigation tested pre-shaded 3Y-TZP materials on optical, mechanical and structural properties and calculated correlations between these properties.

Methods: Seven A2-shaded 3Y-TZP zirconia materials were investigated on translucency (T) via UV-vis-spectrophotometer, fracture load of 3-unit FDPs (FL), biaxial flexural strength (FS), Chevron-Notch Beam (CNB), fracture toughness (K) and Martens parameter (hardness: HM and indentation modulus: E). FL, FS and K were measured in a universal testing machine.

Different polishing methods for zirconia: impact on surface, optical, and mechanical properties.

Objectives: To test the impact of polishing strategies on zirconia properties.

Materials And Methods: One hundred eight zirconia specimens were divided into nine groups (n = 12/group). Seven groups were polished in the white-stage with either (1) a felt wheel (FW), (2) a felt wheel combined with a polishing paste (FWP), (3) a goat hair brush (GB), (4) a goat hair brush combined with a polishing paste (GBP), (5) a green-state finishing kit (FK), (6) a universal polisher (UP), or (7) with SiC polishing paper (PP), and sintered.

Impact of high-speed sintering on translucency, phase content, grain sizes, and flexural strength of 3Y-TZP and 4Y-TZP zirconia materials.

Statement Of Problem: The lengthy sintering time of zirconia is costly and limits applications. The consequences of shortening the sintering time are mainly unknown.

Purpose: The purpose of this in vitro study was to test and compare 2 high-speed sintering protocols and 1 conventional sintering protocol on the translucency, phase content, grain sizes, and flexural strength of 3 zirconia materials.

The human papillomavirus type 8 E2 protein induces skin tumors in transgenic mice.

Transgenic mice expressing early genes of the cutaneous human papillomavirus 8 (HPV8) spontaneously develop skin papillomas, epidermal dysplasia, and squamous cell carcinoma (6%). As the HPV8 protein E2 revealed transforming capacity in vitro, we generated three epidermal specific HPV8-E2-transgenic FVB/N mouse lines to dissect its role in tumor development. The rate of tumor formation in the three lines correlated with the different E2-mRNA levels.

Expression of matrix metalloproteinase (MMP)-2, MMP-9, MMP-13, and MT1-MMP in skin tumors of human papillomavirus type 8 transgenic mice.

Human papillomaviruses (HPV) are small DNA viruses that induce a wide variety of hyperproliferative lesions in cutaneous and mucosal epithelia. It is proposed that HPV is involved in non-melanoma skin cancer development. We have previously shown that HPV8 transgenic mice spontaneously develop papillomatous skin tumors.