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Objective To investigate the influence of surface treatments conducted in presintering and postsintering stages on flexural strength and optical properties of zirconia. Materials and methods Specimens were milled from partially sintered zirconia blocks in different geometries and divided into three main groups as presintered, postsintered, and control groups. Test groups were further divided into three subgroups (n = 10) according to the surface treatments conducted (grinding, Er,Cr:YSGG laser irradiation, air-borne particle abrasion [APA]). Four-point flexural strength (σ) test and Weibull analysis were conducted. Color differences (ΔE00 ) and translucency parameter (TPab ) were calculated with a spectrophotometer. Surfaces of specimens were scrutinized under FESEM. Data were statistically analyzed. Results Postsintered groups exhibited higher σ values (P 0.8). Higher TPab values were obtained and deeper scratches were observed in presintered groups. Conclusions Surface treatments performed at postsintering stage had a favorable effect on the flexural strength of all specimens. Surface treatments performed before sintering increased translucency and caused higher ΔE00 values. Clinical significance Surface treatments performed at different sintering stages can alter mechanical and optical properties of zirconia.

Statement of problem The influences of coloring and sintering procedures on the optical and mechanical properties of monolithic zirconia have not been thoroughly investigated. Purpose The purpose of this in vitro study was to investigate the effects of the coloring procedure and of varying final sintering temperatures on the translucency parameter (TP) and biaxial flexural strength (BFS) of monolithic zirconia. Material and methods Disk-shaped specimens (N=210) of 2 different monolithic zirconia brands (Vita YZ HT White [VYZa]; Vita YZ HT Color A2 [VYZb]; Prettau Zirkonzahn [PZ]; Prettau Anterior Zirkonzahn [PZA]) with a diameter of 15 mm and a thickness of 1.0 ±0.05 mm were prepared. Half of the specimens prepared from noncolored blocks (VYZa, PZ, and PZA) received coloring liquid application. Then, the specimens were divided into 3 subgroups (n=10) according to the final sintering temperatures (1350°C, 1450°C, and 1600°C). The TP was determined by using a reflection spectrophotometer, and the BFS was tested with the piston-on-3-ball method in a universal testing machine. Data were statistically analyzed by multivariate multiple regression and Bonferroni tests (α=.05). Results Significant differences were obtained among the groups based on the results of the TP and BFS ( P P P >.05). Conclusions Increased sintering temperature leads to increased translucency with minimal impact on the BFS. The coloring procedure should be considered at the time of material selection to avoid possible reduction in translucency.

As a result of serial examinations of two patients with leiomyosarcoma of the stomach, it is felt that the gastroscopic picture at times may be distinctive enough to warrant inclusion of this tumor among the gastroscopically diagnosable diseases. The present findings were those of malignant intramural infiltration with prominent smooth non-ulcerated hemispheric nodules, and increased translucency of the overlying mucosa. The gastroscopic findings may return to normal temporarily following supervoltage roentgen therapy.

Involutional ptosis is a ptosis of varying degree. There is good levator function with a high lid fold and increased lid excursion on downgaze. There may be increased translucency of the upper lid. We reviewed all adult ptosis cases over the past three years at Sydney Eye Hospital and found 20 cases to have aponeurotic defects such as a dehiscence or disinsertion. Ninety percent of our cases had a positive 10% phenylephrine test. We recommend that all operations be done under local anaesthesia without adrenaline, overcorrecting by 1-2 mm at the time of surgery.