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Made available in DSpace on 2022-04-28T17:22:40Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-07-01 Little is known about the impact of bleaching on the optical properties of computer-aided design and computer-aided manufactured (CAD-CAM) monolithic materials. The aim of the present study was to evaluate the effect of one session of in-office bleaching on stain removal, staining susceptibility, translucency, and whiteness variations of CAD-CAM monolithic materials. Disks were fabricated from Lava Ultimate (LU), Vita Enamic (VE), Vita Suprinity (VS), and IPS e.max CAD (IPS). A spectrophotometer was used to register Commission Internationale de l'Eclairage L*a*b* coordinates. For stain removal, 80 specimens from each material were assessed at baseline (R-0) and after immersion in deionized water or coffee for 36.5 days followed or not by bleaching with 40% hydrogen peroxide (R-1). For staining susceptibility, 80 specimens from each material were analyzed at baseline (R-0'), and after having been bleached or not and immersed in deionized water or coffee (R-1'). Both analyses were calculated as the color difference (Delta E-00) between R-1-R-0 and R-1'-R-0', respectively. Differences in translucency (Delta TP00) and whiteness (.WID) between R-1-R-0 and R-1'-R-0' were also calculated. Data were analyzed by three-way ANOVA and the Games-Howell post hoc test (alpha=0.05). Clinical significance was based on 50%:50% perceptibility and acceptability thresholds for Delta E-00, Delta TP00 and Delta W-ID, respectively. Surfaces were analyzed by scanning electron microscopy. Coffee increased Delta E-00 in LU, VE, and VS, and decreased their translucency and whiteness, whereas the IPS had only its whiteness affected. Bleaching after immersion in coffee decreased Delta E-00 in LU and VE, and increased translucency and whiteness of LU, VE, and VS. No effect was observed on IPS. Bleaching before immersion in coffee decreased translucency of LU, but within the acceptable interval, while VE exhibited lower Delta E-00, and became more translucent and less dark. Both VS and IPS were not affected. One session of in-office bleaching benefited optical properties of the previously stained LU, VE, and VS, without increasing their susceptibility to staining or adversely providing clinically unacceptable variations in their translucency and whiteness. All variations exhibited by the IPS were below the perceptible threshold. Sao Paulo State Univ UNESP, Dept Dent Mat & Prosthodont, Sch Dent, Araraquara, SP, Brazil Sao Paulo State Univ UNESP, Sch Dent, Araraquara, SP, Brazil Sao Paulo State Univ UNESP, Sch Dent, Dept Social Dent, Araraquara, SP, Brazil Sao Paulo State Univ UNESP, Dept Dent Mat & Prosthodont, Sch Dent, Araraquara, SP, Brazil Sao Paulo State Univ UNESP, Sch Dent, Araraquara, SP, Brazil Sao Paulo State Univ UNESP, Sch Dent, Dept Social Dent, Araraquara, SP, Brazil

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.

A woman in her 20s presented to dermatology clinic with a four year history of a mildly itchy hypopigmented patch in her natal cleft, and similar itchy lesions that had gradually appeared on the back of both knees over the past six months (fig 1, fig 2). The lesions ranged from white to brown. Fig 1 Hypopigmented atrophic plaques in upper part of natal cleft Fig 2 Hypopigmented atrophic plaques in popliteal fossae Treatment with topical antifungal creams for suspected candidal intertrigo was unsuccessful. Cutaneous examination revealed multiple ill defined hypopigmented plaques in the upper part of the natal cleft and both popliteal fossae. On close inspection, the affected skin showed fine wrinkling and increased translucency (not clear in the figure) …

Objectives The present narrative review was focused on the optical properties, surface treatment, adhesion, and clinical indications of zirconia-reinforced lithium silicate ceramics (ZLS) for Computer-aided design / Computer-aided manufacturing (CAD/CAM) technologies. Data/Sources A literature search was performed by 3 calibrated independent researchers on PubMed, Scopus, Embase, Google Scholar, Dynamed, and Open Grey. The criteria for inclusion were: 1) papers addressing at least one of the following variables about ZLS: optical properties, surface treatment, adhesion, and clinical indications; 2) in vitro, in silico, or in vivo studies; 3) case reports; 4) systematic reviews. The exclusion criteria were: 1) animal studies; 2) non-dental studies; 3) studies only focusing on ZLS used in the heat-pressed process. Study Selection 98 records among in vitro studies and case reports were included. Conclusions Despite the promising microstructure characteristics of ZLS, increased translucency compared to lithium disilicate ceramics (LS2) was not proven, but acceptable color changes and stability were reported. Mechanical polishing was the most effective method to reduce surface roughness. Moreover, machinability and handling of ZLS resulted harder than LS2. Conventional acid etching procedures seemed effective in conditioning ZLS surface, but no protocol has been established yet. Besides, silane-coupling and dual-curing resin cements were recommended. Clinical Significance ZLSs can be used for anterior and posterior fixed single-unit CAD/CAM restorations onto both natural teeth and implants, but do not seem to represent a viable treatment option for endocrowns onto posterior teeth or fixed dental prostheses.

Scoring is a common method to evaluate eggshell translucency, and it mainly depends on the area and the density of translucent spots in eggshells. However, the lack of common scoring criteria and the difficulty of quantitatively measuring spots in eggshells impede effective comparisons between research papers and greatly hinder the progress of research on translucent eggshell. To make measurement of translucent eggshells more objective, we optimized the scoring method and compared it with 2 new methods: grayscale recognition and the colorimeter method. Briefly, a total of 354 eggs from 600, 395-day-old dwarf brown laying hens were collected and classified into 4 score groups according to their degree of translucency. This subjective process was repeated 5 times. Then, we captured the profile side of each egg using a camera and measured spot characteristics using grayscale recognition, which involved measuring the quantity of spots (QS), diameter of each spot (DS), average area of each spot (AAES), sum of spot areas (SUSA), sum of shell area (SUSHA), and ratio of SUSA to SUSHA (RSS) on the eggshell. Furthermore, the L, A, and B values of each egg at the sharp, middle, and blunt ends were separately measured using a colorimeter. As a result, average values of 31.31, 29.78, 29.81, and 9.08% of all eggs were divided into score levels 1, 2, 3, and 4 (from opaque to translucent), which correspond with RSS values of 1.34, 3.23, 6.21, and 11.89%, respectively. By grayscale recognition, QS, DS, AAES, SUSA, SUSHA, and RSS all increased along with increased translucency scores (P < 0.05). Using scoring, an egg with a specific RSS value was more easily assigned to a specific score level (50%) or adjacent score levels (50%). The L, A, and B values of eggshells in score level 1 were significantly different from those of eggshells in levels 3 or 4; however, there were no significant differences between any adjacent score levels. In summary, the present study explored objective reference metrics to measure eggshell translucency.

The removal of pineapple crowns and slips during the final stage of fruit development can alter source-sink relationships and fruit quality. Published results have reported both positive and negative effects of both crown removal and slip removal on fruit size and quality. In this study, four treatments: control (no treatment), slips removed by hand, crown removed with a knife, and both crowns and slips removed were evaluated to clarify the effect of crown removal and slip removal on fruit quality. Crowns and slips were removed one to two months before expected harvest date, soon after slip development began. The trial was repeated three times throughout the year. Crown and slip removal had minimal effect on fruit weight, shell color and titratable acidity at harvest. Removal of the crown or removal of the crown and slips did increase total soluble solids about 1%. Removal of the crown increased translucency, though in the warm season translucency severity was low. Fruit with larger crowns had less translucency. Slip removal increased translucency slightly, but when both the crowns and slips were removed the effect on translucency severity was not additive. The results support published conclusions that crowns and artificial shade reduce translucency. A negative correlation was found between the air temperature four months before harvest at the beginning of crown growth and final crown weight. Rainfall two to four months before harvest had a significant effect on slip weight. The results suggested that crown removal can impact fruit quality and the occurrence of the fruit translucency disorder with a significant seasonal response.

This study evaluated the masking ability of different porcelain thicknesses and combination of enamel and/or dentin porcelain layers over simulated background dental substrates with higher (A2) and lower (C4) color values. Combination of the enamel (E) and dentin (D) monolayer porcelain disks with different thicknesses (0.5 mm, 0.8 mm, and 1 mm) resulted in the following bilayer groups (n=10): D1E1, D1E0.8; D1E0.5; D0.8E0.8; D0.8E0.5, and D0.5E0.5. CIELAB color coordinates were measured with a spectrophotometer. The translucency parameter of mono and bilayer specimens and the masking ability estimated by color variation (ΔE*ab) of bilayer specimens over simulated dental substrates were evaluated. Linear regression analysis was used to investigate the relationships translucency parameter × ΔE*, translucency parameter × porcelain thickness, and ΔE* × porcelain thickness. Data were analyzed statistically (α= 0.05). Thinner porcelain disks were associated with higher translucency. Porcelain monolayers were considerably more translucent than bilayers (enamel + dentin). Dentin porcelain was less translucent than enamel porcelain with same thickness. ΔE* was always lower when measured over A2 background. Higher ΔE* was observed for the C4 background, indicating poorer masking ability. Increased ΔE* was significantly associated with increased translucency for both backgrounds. Decreased translucency and ΔE* were associated with increased total porcelain thickness or increased dentin thickness for both backgrounds. In conclusion, increased porcelain thickness (particularly increased dentin layer) and increased porcelain opacity resulted in better masking ability of the dental backgrounds.

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.

One hundred and five samples of pig backfat were assessed for appearance (colour and translucency) and hardness. The fatty acid profile of a selected subset of 50 samples was determined. Increased yellow colour was associated with increased linoleic and α-linolenic acid percentages. Increased translucency and fat softness were associated with decreased percentages of palmitic and stearic and oleic acid and a concurrent increase in the proportions of linoleic and α-linolenic acid. Oleic acid was found to be the single highest component (33.0-45.4%) and linoleic to show the greatest variation in range (9.8-28.4%).

Goldfish eggs retained in the ovarian cavity become overripe within 24 h after ovulation. Three stages of an overripening process could be identified. The overripe egg is characterized by increased translucency, movement of cytoplasm with cortical alveoli and unfused oil droplets to the animal pole, partial breakdown of the cortical alveoli, and finally the intermingling of these cell components with yolk granules in later stages. It is also larger than the newly ovulated egg and its chorion is thinner with surface modifications involving the recessing or disappearance of the pore plugs.

Swyer-James syndrome is an uncommon disease with unknown aetiology. It is generally discovered on a chest radiograph as increased translucency involving one hemithorax because of diminished vascular markings. Pulmonary vascularization on the affected side is greatly reduced leading to radiological translucency. Myocardial bridging describes an angiographic entity, which is any degree of systolic narrowing of a coronary artery observed in at least one angiographic projection. It is a congenital anomaly of the coronary artery and may occur in 5-12% of the human population. We report a patient suffering from chest tightness and with diagnosed Swyer-James syndrome also having myocardial bridge. (C) 2003 Elsevier Ireland Ltd. All rights reserved.

Although the glass-ionomer cements were developed in the 1970s, it is only recently that their clinical use has expanded internationally. Improvements in formulation have resulted in better mechanical strengths, increased translucency and, more importantly, faster setting times. Their use as ‘dentine substitutes’ has expanded the versatility of laminate restorations in anterior and posterior teeth and the introduction of the silver-cermet ionomers provided materials with increased abrasion resistance. Glass-ionomer cements have a number of unique properties, including adhesion to moist tooth structure, biological compatibility, and anticariogenic properties due to their fluoride release. One of their major roles is the treatment of early carious lesions using microcavity preparation. However, like all materials, glass-ionomer cements have their weaknesses, the prime ones being lack of toughness, early water sensitivity, and porosity leading to poor surface polish. Future research should concentrate on correcting these deficiencies.

Cystic testicular tubular dilatation was seen in ducklings fed a ration containing furazolidone at 250, 400, 550, or 700 ppm for 28 days. Gross evidence of cystic testicular dilatation was observed at necropsy in 16% (32/203) of the ducklings that survived to the end of the study. Gross testicular lesions consisted of various degrees of enlargement with increased translucency in moderately to severely enlarged testicles. Histological evidence of cystic testicular dilatation was present in 45% (41/91) of the testicles examined. Histologically, the tubules were in various states of dilatation with attenuation of the seminiferous epithelium proportional to the severity of dilatation. In the most severely affected testicles, tubules were greatly dilated, distorted, and fluid-filled, with extensively flattened epithelium visible on the inner margin of the tubule as a thin rim of cytoplasm with a protuberant nucleus. Interstitial tissues were compressed to thin septa between the dilated tubules.

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.

An intraperitoneal tumor which on a radiograph produces an increased translucency instead of a density is highly suggestive of a dermoid cyst. This becomes definite if the tumor wall itself is visualized. These findings will not be noted on an ordinary ovarian cyst or uterine fibroid. Differential diagnosis from lipoma and “gas filled ovarian cyst” is discussed.

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.

The occurrence of discrete gray areas, often called plaques, in the sclera just in front of the medial and lateral recti is a common finding in old age. If these areas are excised together with a rim of normal sclera and held before a light, they show increased translucency. They are not pigmented and are not plaques in the usual sense of the word. Their gray color is due to enhanced visibility of the uveal pigment, but occasionally they do contain calcific plaques. Since these focal spots are not known to have clinical significance, they have not attracted much attention and are poorly described in current textbooks and most reviews. The scanty literature up to 1945 was collected by Roper 1 in an article which incidentally presents the best clinical illustrations of the entity in the literature. That article emphasizes the association of the spots with age and points up

The function of the facet-separating pigments in the compound eyes of the fruitfly Drosophila melanogaster with hypernormal (se), normal (+), subnormal (wa), and missing (w) pigmentation was studied by investigation of: (1) the in-flight optomotor responses to movement of striped patterns with a mean brightness of 300 cd/m2, and (2) the retinal action potentials evoked by flashes in a program of .0003 cd/m2 average brightness. The pigment deficient mutants (w a, w) are less sensitive to the pattern contrast in the bright adapted state, and more sensitive to the flash intensity in the dark adapted state than either the wild-type (+) or the overpigmented mutant(se). These differences are complementary and can be explained by the increased translucency of the pigment cells. Thus the photoreceptors in the equally illuminated eyes of the normal and mutant animals +, se, w a, and w are expected to receive light in a ratio of about 1∶1∶7∶19. However the sensitivity of the receptors as well as the half-peak widths and the density of their visual fields are apparently independent of the eye pigmentation and seem to be equal at common levels of adaptation. The effects of omnidirectional excess light reaching the receptors of the pigment deficient mutants can be simulated in less translucent eyes: when certain amounts of background illumination were combined with the optomotor stimulus in the visual fields of the wild-type receptors it was possible to elicit the predicted “mutant behavior”.