SAM domain variants of EPHB4 associated with aberrant signaling are linked to lymphatic-related fetal hydrops and facial dysmorphology.

Variants in EPHB4 (Ephrin type B receptor 4), a transmembrane tyrosine kinase receptor, have been identified in individuals with various vascular anomalies including Capillary Malformation-Arteriovenous Malformation syndrome 2 and lymphatic-related (non-immune) fetal hydrops (LRHF). Here, we identify two novel variants in EPHB4 that disrupt the SAM domain in two unrelated individuals. Proband 1 presented within the LRHF phenotypic spectrum with hydrops, and proband 2 presented with large nuchal translucency prenatally that spontaneously resolved in addition to dysmorphic features on exam postnatally. These are the first disease associated variants identified that do not disrupt EPHB4 protein expression or tyrosine-kinase activity. We identify that EPHB4 SAM domain disruptions can lead to aberrant downstream signaling, with a loss of the SAM domain resulting in elevated MAPK signaling in proband 1, and a missense variant within the SAM domain resulting in increased cell proliferation in proband 2. This data highlights that a functional SAM domain is required for proper EPHB4 function and vascular development.

Clinical implications of crown-rump length discordance at 11 to 14 weeks in dichorionic twins.

BACKGROUND: Crown-rump length discordance, defined as ≥10% discordance, has been investigated as an early sonographic marker of subsequent growth abnormalities and is associated with an increased risk of fetal loss in twin pregnancies. Previous studies have not investigated the prevalence of fetal aneuploidy or structural anomalies in twins with discordance or the independent association of crown-rump length discordance with adverse perinatal outcomes. Moreover, data are limited on cell-free DNA screening for aneuploidy in dichorionic twins with discordance. OBJECTIVE: This study aimed to evaluate whether crown-rump length discordance in dichorionic twins between 11 and 14 weeks of gestation is associated with a higher risk of aneuploidy, structural anomalies, or adverse perinatal outcomes and to assess the performance of cell-free DNA screening in dichorionic twin pregnancies with crown-rump length discordance. STUDY DESIGN: This was a secondary analysis of a multicenter retrospective cohort study that evaluated the performance of cell-free DNA screening for the common trisomies in twin pregnancies from December 2011 to February 2020. For this secondary analysis, we included live dichorionic pregnancies with crown-rump length measurements between 11 and 14 weeks of gestation. First, we compared twin pregnancies with discordant crown-rump lengths with twin pregnancies with concordant crown-rump lengths and analyzed the prevalence of aneuploidy and fetal structural anomalies in either twin. Second, we compared the prevalence of a composite adverse perinatal outcome, which included preterm birth at <34 weeks of gestation, hypertensive disorders of pregnancy, stillbirth or miscarriage, small-for-gestational-age birthweight, and birthweight discordance. Moreover, we assessed the performance of cell-free DNA screening in pregnancies with and without crown-rump length discordance. Outcomes were compared with multivariable regression to adjust for confounders. RESULTS: Of 987 dichorionic twins, 142 (14%) had crown-rump length discordance. The prevalence of aneuploidy was higher in twins with crown-rump length discordance than in twins with concordance (9.9% vs 3.9%, respectively; adjusted relative risk, 2.7; 95% confidence interval, 1.4-4.9). Similarly, structural anomalies (adjusted relative risk, 2.5; 95% confidence interval, 1.4-4.4]) and composite adverse perinatal outcomes (adjusted relative risk, 1.2; 95% confidence interval, 1.04-1.3) were significantly higher in twins with discordance. A stratified analysis demonstrated that even without other ultrasound markers, there were increased risks of aneuploidy (adjusted relative risk, 3.5; 95% confidence interval, 1.5-8.4) and structural anomalies (adjusted relative risk, 2.7; 95% confidence interval, 1.5-4.8) in twins with CRL discordance. Cell-free DNA screening had high negative predictive values for trisomy 21, trisomy 18, and trisomy 13, regardless of crown-rump length discordance, with 1 false-negative for trisomy 21 in a twin pregnancy with discordance. CONCLUSION: Crown-rump length discordance in dichorionic twins is associated with an increased risk of aneuploidy, structural anomalies, and adverse perinatal outcomes, even without other sonographic abnormalities. Cell-free DNA screening demonstrated high sensitivity and negative predictive values irrespective of crown-rump length discordance; however, 1 false-negative result illustrated that there is a role for diagnostic testing. These data may prove useful in identifying twin pregnancies that may benefit from increased screening and surveillance and are not ascertained by other early sonographic markers.

Adverse pregnancy outcome in fetuses with early increased nuchal translucency: prospective cohort study.

OBJECTIVES: An increased nuchal translucency (NT) thickness of ≥ 3.5 mm is a well-established marker for congenital anomalies and adverse pregnancy outcome between 11 and 14 weeks' gestation, but little is known about its performance as a screening tool before 11 weeks. We aimed to investigate, in a prospective setting, whether fetuses with increased NT before 11 weeks are at risk for adverse pregnancy outcome. METHODS: This was a prospective cohort study including pregnant women with a viable fetus with NT ≥ 2.5 mm and a crown-rump length (CRL) < 45 mm. All included women were referred to our fetal medicine unit (FMU) and scheduled for a follow-up scan where the NT was remeasured after 1 week when the CRL was > 45 mm. Two groups were evaluated: cases with a normalized NT (< 3.5 mm) and cases with persistently increased NT (≥ 3.5 mm). The cases were monitored until 4 weeks after delivery. The main outcome was a composite adverse outcome of aneuploidy, other genetic disorders, structural anomalies and pregnancy loss. We performed subgroup analyses of NT thickness at inclusion and normalized or persistently increased NT at follow-up. RESULTS: The study included 109 cases, of which 39 (35.8%) had an adverse pregnancy outcome. Of these, 64.1% (25/39) were aneuploid, corresponding to 22.9% (25/109) of the total study population. In the subgroups of NT thickness at inclusion of 2.5-3.4 mm, 3.5-4.4 mm and ≥ 4.5 mm, an adverse outcome was reported in 22.0% (9/41), 40.0% (18/45) and 52.2% (12/23), respectively. In fetuses with a normalized NT and without ultrasound abnormalities at the follow-up scan, the incidence of adverse outcome was 8.5% (5/59), of which 5.1% (3/59) cases were aneuploid. CONCLUSIONS: Fetuses with an early increased NT thickness are at considerable risk of an adverse pregnancy outcome, even if the NT normalizes after 11 weeks. Not all congenital anomalies can be diagnosed with routine first-trimester screening, such as non-invasive prenatal testing and/or a first-trimester anomaly scan. Therefore, expectant parents should always be referred to a FMU for detailed ultrasonography. Invasive prenatal testing should be offered if an increased NT of ≥ 2.5 mm is observed before 11 weeks' gestation. © 2024 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Resultado adverso del embarazo en fetos con aumento precoz de la translucencia nucal: estudio prospectivo de cohortes OBJETIVOS: El aumento del grosor de la translucencia nucal (TN) de ≥3,5 mm es un marcador bien establecido de anomalías congénitas y resultados adversos del embarazo entre las semanas 11 y 14 de gestación, pero se sabe poco sobre su rendimiento como herramienta de cribado antes de las 11 semanas. El objetivo fue investigar, en un contexto prospectivo, si los fetos con aumento de la TN antes de las 11 semanas corren riesgo de presentar resultados adversos del embarazo. MÉTODOS: Se trató de un estudio prospectivo de cohortes que incluyó a embarazadas con un feto viable con una TN ≥2,5 mm y una longitud céfalo­caudal (LCC) <45 mm. Todas las mujeres incluidas fueron remitidas a una unidad de medicina fetal (UMF) y con cita para una prueba de seguimiento en la que se volvió a medir la TN al cabo de 1 semana cuando la LCC era >45 mm. Se evaluaron dos grupos: casos con una TN normalizada (<3.5 mm) y casos con una TN persistentemente aumentada (≥3,5 mm). A los casos se les dio seguimiento hasta 4 semanas después del parto. El resultado principal fue un resultado adverso compuesto de aneuploidía, otros trastornos genéticos, anomalías estructurales y pérdida del embarazo. Se realizaron análisis de subgrupos del grosor de la TN en el momento de la inclusión y de la TN normalizada o persistentemente aumentada en el seguimiento. RESULTADOS: El estudio incluyó 109 casos, de los cuales 39 (35,8%) tuvieron un resultado adverso del embarazo. De ellos, el 64,1% (25/39) eran aneuploides, lo que supone el 22,9% (25/109) de la población total del estudio. En los subgrupos de grosor de la TN en el momento de la inclusión de 2,5­3,4 mm, 3,5­4,4 mm y ≥4,5 mm, se notificó un resultado adverso en el 22,0% (9/41), el 40,0% (18/45) y el 52,2% (12/23), respectivamente. En los fetos con una TN normalizada y sin anomalías ecográficas en la ecografía de seguimiento, la incidencia de resultados adversos fue del 8,5% (5/59), de los cuales el 5,1% (3/59) de los casos eran aneuploides. CONCLUSIONES: Los fetos con un aumento precoz del grosor de la TN corren un riesgo considerable de sufrir un resultado adverso del embarazo, incluso si la TN se normaliza después de 11 semanas. No todas las anomalías congénitas pueden diagnosticarse con un cribado rutinario en el primer trimestre, como las pruebas prenatales no invasivas y/o una ecografía de anomalías en el primer trimestre. Por lo tanto, los futuros padres siempre deben ser remitidos a una UMF para una ecografía detallada. Se debería ofrecer una prueba prenatal invasiva si se observa un aumento de la TN de ≥2,5 mm antes de las 11 semanas de gestación.

The cospecification of the shape and material properties of light permeable materials.

The problem of extracting the three-dimensional (3D) shape and material properties of surfaces from images is considered to be inherently ill posed. It is thought that a priori knowledge about either 3D shape is needed to infer material properties, or knowledge about material properties are needed to derive 3D shape. Here, we show that there is information in images that cospecify both the material composition and 3D shape of light permeable (translucent) materials. Specifically, we show that the intensity gradients generated by subsurface scattering, the shape of self-occluding contours, and the distribution of specular reflections covary in systematic ways that are diagnostic of both the surface's 3D shape and its material properties. These sources of image covariation emerge from being causally linked to a common environmental source: 3D surface curvature. We show that these sources of covariation take the form of "photogeometric constraints," which link variations in intensity (photometric constraints) to the sign and direction of 3D surface curvature (geometric constraints). We experimentally demonstrate that this covariation generates emergent cues that the visual system exploits to derive the 3D shape and material properties of translucent surfaces and demonstrate the potency of these cues by constructing counterfeit images that evoke vivid percepts of 3D shape and translucency. The concepts of covariation and cospecification articulated herein suggest a principled conceptual path forward for identifying emergent cues that can be used to solve problems in vision that have historically been assumed to be ill posed.

Selection of prenatal screening with nuchal translucency > 95th centile and below 99th centile: a 4-year observational study with real-world data.

OBJECTIVE: We sought to analyze the genetic outcomes of fetuses with nuchal translucency (NT) > 95th centile, and determine whether prenatal genetic counseling, chromosomal microarray analysis (CMA) or non-invasive prenatal testing (NIPT) are truly beneficial for the outcomes of fetuses with increased NT > 95th centile and below 99th centile. MATERIALS AND METHODS: A total of 535 pregnant women were included in this study, with a fetal NT > 95th centile at 11-13+6 weeks of gestation from January 2017 to December 2020. 324 pregnant women with fetal NT > 95th centile and below 99th centile combined with other risk factors and NT > 99th centile received prenatal diagnostic karyotype analysis and CMA, and 211 pregnant women with fetal isolated increased NT > 95th centile and below 99th centile were selected to carry out NIPT. RESULTS: A total of 211 pregnant women who underwent NIPT were included in the study, NIPT results showed that 8 high-risk cases were confirmed by prenatal diagnosis. Overall, the detection rate of NIPT was 3.79%. A total of 324 pregnant women with fetal NT > 95th centile and below 99th centile, along with other risk factors, and those with fetal NT > 99th centile, received karyotype analysis and CMA for prenatal diagnosis. Among them, a total of 73 genetic abnormalities were detected, including 45 cases of chromosomal aneuploidy, 7 cases of structural abnormalities, and 21 cases of copy number variations (CNVs) with a size of less than 10 Mb. In addition, the 73 women with genetic abnormalities are divided into three groups based on the NT measurement (Group 1: Fetuses with NT > 95th centile and below 99th centile, Group 2: Fetuses with NT > 99th centile, and Group 3: Fetuses with NT > 99th centile). 13.11% (8/61) of pathogenic genetic abnormalities (6 chromosomal aneuploidy, 1 structural abnormality, and 1 likely pathogenic CNV) will be missed if genetic counseling and prenatal genetic testing were not conducted in fetuses with increased NT > 95th centile and below 99th centile combined with other risks. Pathogenic CNVs were the most common abnormalities in group 3, and one likely pathogenic CNV was detected in group 1 and group 3, respectively, and a total of 14 CNVs of unknown clinical significance (VOUS) were detected. CONCLUSIONS: Through this study, we demonstrated that the critical value of NT > 95th centile for invasive detection or NIPT. Invasive testing combined with CMA may be recommended for fetuses with NT > 95th centile and below 99th centile and with other risks. But when isolated NT > 95th centile and below 99th centile, NIPT would be appropriate.

Diagnostic yield of copy number variation sequencing in fetuses with increased nuchal translucency: a retrospective study.

OBJECTIVE: To assess the efficacy of copy number variation sequencing (CNV-seq) and karyotyping for prenatal detection of chromosomal abnormalities in fetuses with increased nuchal translucency. METHODS: Amniotic fluid samples were extracted from 205 fetuses with increased nuchal translucency (NT ≥ 2.5 mm), diagnosed by ultrasound between gestational ages of 11 and 13 + 6 weeks. Karyotyping and CNV-seq were performed for detecting chromosomal abnormalities. RESULTS: There are 40 fetuses (19.51%) showing increased NT detected with chromosomal abnormalities in karyotyping, and trisomy 21 was found to be the most common abnormalities. There are 50 fetuses (24.39%) identified with chromosomal abnormalities by CNV-seq. The detection of the applied techniques indicated that CNV-seq revealed higher chromosomal aberrations. The risk of chromosomal abnormalities was significantly increased with NT thickening, from 13.64% in the NT group of 2.5-3.4 mm, 38.64% in the NT group of 3.5-4.4 mm, and to 51.72% in the NT group of over 4.5 mm (P < 0.05). The investigated cases with increased NT with presence of soft markers in ultrasound or high risk in non-invasive prenatal testing presented chromosomal abnormalities in higher rates, comparing with those with isolated NT or low risk (P < 0.05). CONCLUSION: The results indicated that the risk of chromosomal abnormalities was associated with the NT thickness, detected by karyotype or CNV-seq. The combination application of two analysis was efficient to reveal the possible genetic defects in prenatal diagnosis. The finding suggested that the detection should be considered with ultrasonographic soft markers, and the NT thickness of 2.5-3.4 mm could be a critical value for detecting chromosomal abnormalities to prevent the occurrence of missed diagnosis.

Development of a 3D-printed nuchal translucency model: a pilot study for prenatal ultrasound training.

BACKGROUND: We used two 3D ultrasound volumes of fetal heads at 13 weeks to create live-size 3D-printed phantoms with a view to training or assessment of diagnostic abilities for normal and abnormal nuchal translucency measurements. The phantoms are suitable for use in a water bath, imitating a real-life exam. They were then used to study measurement accuracy and reproducibility in examiners of different skill levels. METHODS: Ultrasound scans of a 13 + 0-week fetus were processed using 3D Slicer software, producing a stereolithography file for 3D printing. The model, crafted in Autodesk Fusion360™, adhered to FMF guidelines for NT dimensions (NT 2.3 mm). Additionally, a model with pathologic NT was designed (NT 4.2 mm). Printing was performed via Formlabs Form 3® printer using High Temp Resin V2. The externally identical looking 3D models were embedded in water-filled condoms for ultrasound examination. Eight specialists of varying expertise levels conducted five NT measurements for each model, classifying them in physiological and abnormal models. RESULTS: Classification of the models in physiological or abnormal NT resulted in a detection rate of 100%. Average measurements for the normal NT model and the increased NT model were 2.27 mm (SD ± 0.38) and 4.165 mm (SD ± 0.51), respectively. The interrater reliability was calculated via the intraclass correlation coefficient (ICC) which yielded a result of 0.883, indicating robust agreement between the raters. Cost-effectiveness analysis demonstrated the economical nature of the 3D printing process. DISCUSSION: This study underscores the potential of 3D printed fetal models for enhancing ultrasound training through high inter-rater reliability, consistency across different expert levels, and cost-effectiveness. Limitations, including population variability and direct translation to clinical outcomes, warrant further exploration. The study contributes to ongoing discussions on integrating innovative technologies into medical education, offering a practical and economical method to acquire, refine and revise diagnostic skills in prenatal ultrasound. Future research should explore broader applications and long-term economic implications, paving the way for transformative advancements in medical training and practice.

Does the internal surface treatment technique for enhanced bonding affect the color, transparency, and surface roughness of ultra-transparent zirconia?

PURPOSE: To investigate the effects of different surface treatments and thicknesses on the color, transparency, and surface roughness of ultra-transparent zirconia. METHODS: A total of 120 Katana ultra-translucent multi-layered zirconia specimens were divided into 12 groups according to the thickness (0.3, 0.5, and 0.7 mm) and surface treatment (control, airborne particle abrasion [APA], lithium disilicate coating, and glaze on). Color difference (ΔE00) and relative translucency parameter (RTP00) were calculated using a digital spectrophotometer. The surface roughness (Ra, Rq, Sa, and Sq) was measured using a non-contact profile scanner. The surface morphologies and microstructures of the samples were observed using a tungsten filament scanning electron microscope. Statistical analyses were performed by one-way and two-way analysis of variance (ANOVA) followed by post hoc multiple comparisons and Pearson's correlation (α = 0.05). RESULTS: The results showed that the surface treatment, ceramic thickness, and their interactions had significant effects on ΔE00 and RTP00 (p < 0.001). The surface treatment significantly altered the micromorphology and increased the surface roughness of the ceramic samples. APA exhibited the lowest transparency, largest color difference, and highest surface roughness. Zirconia with 0.3 mm and 0.7 mm thicknesses showed strong negative correlations between Sa and RTP00. CONCLUSIONS: The three internal surface treatments significantly altered the surface roughness, color difference, and transparency of ultra-transparent zirconia. As the thickness increased, the influence of the inner surface treatment on the color difference and transparency of zirconia decreased. CLINICAL IMPLICATIONS: For new zirconia internal surface treatment technologies, in addition to considering the enhancement effect on the bonding properties, the potential effects on the color and translucency of high-transparency zirconia should also be considered. Appropriately increasing the thickness of zirconia restorations helps minimize the effect of surface treatment on the optical properties.

Identification of Fetuses at Increased Risk of Trisomies in the First Trimester Using Axial Planes.

INTRODUCTION: The measurement of nuchal translucency (NT) is crucial for assessing risk of aneuploidies in the first trimester. We investigate the ability of NT assessed by a transverse view of the fetal head to detect fetuses at increased risk of common aneuploidies at 11-13 weeks of gestation. METHODS: We enrolled a nonconsecutive series of women who attended our outpatient clinic from January 2020 to April 2021 for aneuploidy screening by means of a first trimester combined test. All women were examined by operators certified by the Fetal Medicine Foundation. In each patient, NT measurements were obtained both from the median sagittal view and transverse view. We calculated the risk of aneuploidy using NT measurements obtained both with sagittal and axial scans, and then we compared the results. RESULTS: A total of 1,023 women were enrolled. An excellent correlation was found between sagittal and transverse NT measurements. The sensitivity and specificity of the axial scan to identify fetuses that were deemed at risk of trisomy 21 using standard sagittal scans were 40/40 = 100.0% (95% confidence interval [CI]: 91.2-100.0) and 977/983 = 99.4% (95% CI: 98.7-99.7), respectively. The sensitivity and specificity of the axial scan to identify fetuses at risk of trisomy 13 or 18 were 16/16 = 100.0% (95% CI: 80.6-100.0) and 1,005/1,007 = 99.8% (95% CI: 99.3-99.9). CONCLUSIONS: When the sonogram, a part of combined test screening, is performed by an expert sonologist, axial views can reliably identify fetuses at increased risk of trisomies without an increase in false negative results.

Is Nuchal Translucency of 3.0-3.4 mm an Indication for cfDNA Testing or Microarray? - A Multicenter Retrospective Clinical Cohort Study.

INTRODUCTION: This study aimed to evaluate the occurrence of clinically relevant (sub)microscopic chromosomal aberrations in fetuses with the nuchal translucency (NT) range from 3.0 to 3.4 mm, which would be potentially missed by cfDNA testing. METHODS: A retrospective data analysis of 271 fetuses with NT between 3.0 and 3.4 mm and increased first trimester combined test (CT) risk in five cohorts of pregnant women referred for invasive testing and chromosomal microarray was performed. RESULTS: A chromosomal aberration was identified in 18.8% fetuses (1:5; 51/271). In 15% (41/271) of cases, trisomy 21, 18, or 13 were found. In 0.7% (2/271) of cases, sex chromosome aneuploidy was found. In 1.1% (3/271) of cases, CNV >10 Mb was detected, which would potentially also be detected by genome-wide cfDNA testing. The residual risk for missing a submicroscopic chromosome aberration in the presented cohorts is 1.8% (1:54; 5/271). CONCLUSION: Our results indicate that a significant number of fetuses with increased CT risk and presenting NT of 3.0-3.4 mm carry a clinically relevant chromosomal abnormality other than common trisomy. Invasive testing should be offered, and counseling on NIPT should include the test limitations that may result in NIPT false-negative results in a substantial percentage of fetuses.

NT >99th centile and cystic hygroma: Which diagnosis, which management and outcome.

OBJECTIVES: To evaluate the prevalence of chromosomal anomalies in fetuses affected by increased nuchal translucency(iNT >99Th centile), cystic hygroma (CH) and cases progressing to fetal hydrops (NIHF) in order to correlate this result to prognosis and perinatal fetal outcomes, improving patient's counseling. METHODS: From January 2020 to December 2023, first trimester screening according to FMF criteria were performed in "Maternal fetal medicine Unit" of Foggia's hospital. We studied and collected clinical data of fetuses affected by nuchal translucency >99th centile (iNT), CH and cases progressing to Fetal Hydrops (non-immune fetal hydrop, NIFH). In these selected cases, we evaluated fetal Karyotype to demonstrate the presence of chromosomal abnormalities, associated to fetal structural anomalies and different pregnancy outcome. RESULTS: We have evaluated 45 cases of iNT, CH, and NIFH, identified by ultrasound during first trimester screening. Of these 45 pregnant women, four were lost to follow-up. Of the 41 pregnancies, 20 cases (48.8%) delivered at our division with newborns discharged in good health. Of the 21 patients (51.2%) who miscarried, only two miscarried spontaneously; the other 19 decided on a medical termination of pregnancy (MTP). The 19 patients who decided for MTP showed genetic abnormalities and/or malformation. The 20 cases of fetuses discharged as healthy newborns were enrolled with the following diagnoses: 5 had a diagnosis of CH (20% of cases), 1 case of NIFH (5% of cases), and 14 of iNT (75% of cases). All these fetuses had a normal karyotype and no major malformations. CONCLUSIONS: Isolated CH diagnosis is more frequent than described in Literature (5 cases out of 12: 41.7%) and their prognosis are better than previously described, with the same outcomes of fetuses with iNT without associated anomalies. The possibility of early diagnosis of chromosomal anomalies, associated malformations or the evolution into hydrops is essential for a complete consultation.

Effect of shade and opacity on color differences and translucency of resin composite veneers over lighter and darker substrates.

To evaluate color differences (ΔE00) and translucency parameters (TP) from mono, bi, and trilayer resin composite veneers using different opacities and shades of resin composite over lighter and darker simulated tooth-colored substrates. Mono, bi, and trilayer veneers (1.5 mm) (n = 12) were made using two shades (A1 and A2) and three opacities (enamel, body, and dentin) of resin composite over simulated lighter (A1) and darker (C4, and C4+) tooth-colored substrates. CIEDE2000 formula was used to calculate ΔE00 considering simulated tooth-colored substrate versus opacities in distinct mono, bi, and trilayer combinations of resin composite over the simulated tooth-colored substrate. The TP was calculated using color coordinates measured over standard white and black backgrounds. Differences in ΔE00 and TP values were calculated with a Three-way Analysis of Variance followed by Tukey's post-hoc test. A1E and A1B monolayer veneers showed similar TP values. Significantly higher ΔE00 values were observed over darker (C4 and C4+), and lower over lighter (A1) simulated tooth-colored substrate. Bilayer and trilayer veneers using dentin opacity provided similar ΔE00 values over the darker tooth-colored substrate. Distinct shades and opacities of resin composite layer combinations over lighter and darker tooth-colored substrates significantly affected TP and ΔE00 values. A1 shade and dentin opacity of monolayer resin composite veneers yielded higher ΔE00 values over darker tooth-colored substrates.

Investigating the impact of post-curing cycles on surface hardness and color stability in 3D printed resin crowns.

This study evaluated the effect of different post-curing cycles on the Vickers hardness, color change, and translucency value of 3D printed methacrylic acid ester-based temporary and permanent crown resins. A total of 300 samples were printed in disk shape (ø:8 mm, thickness: 2 mm) using VarseoSmile Crown Plus (VSC) and VarseoSmile Temp (VST) materials from a 3D printer. These disks were divided into five subgroups (n = 30 each) based on flash-curing cycles (0, 750, 1500, 2250, and 3000). Surface hardness tests and color tests were conducted on both the green state and flash-cured groups. The data were analyzed using univariate analysis of variance (ANOVA). The hardness of 3D printed temporary and permanent crown resin increased with post-curing time. Compared to the post-curing cycle recommended by the manufacturer, no clinically significant color change (ΔE00 ≥ 2.25) was observed in any of the polymerized groups. It was determined that permanent crown material had a more translucent structure than temporary crown material. The interaction between material and post-curing had significant effects on surface hardness, color (ΔE00), and translucency of 3D printed methacrylic acid ester-based resins.

Translucency of bulk-fill composite materials: A systematic review.

OBJECTIVES: To conduct a systematic review on the translucency of bulk-fill (BF) composite materials, evaluating the factors influencing it and its clinical implications. MATERIALS AND METHODS: A systematic search was performed on four databases (Embase, Medline/PubMed, Scopus, and Web of Science) for articles published until October 2, 2023. Search terms were: "translucency," "translucency parameter," "contrast," "contrast ratio," "bulk," "bulk-fill," "bulk fill," "composite," "resin," "resin based," "resin-based," "restoration," and "dental." In vitro studies, written in English language, investigating BF resin-based composites translucency were included. The risk of bias was performed with the RoBDEMAT tool. RESULTS: Of 590 screened articles, 13 were included in this review. They investigated 11 high-viscosity BF and 5 low viscosity ones. The limited number of the identified studies and the heterogeneity of the extracted data did not allow to conduct a meta-analysis. CONCLUSIONS: BF materials exhibit variability in translucency due to variations in experimental designs and the heterogeneous composition. CLINICAL SIGNIFICANCE: BFs may behave differently in masking the substrate or in blending capacity.

Optical properties of dental zirconia, bovine dentin, and enamel-dentin structures.

OBJECTIVE: To evaluate the optical properties and the relative translucency parameter of Ceramill ZI White (3Y-TZP) and Ceramill Zolid FX White (5Y-PSZ) zirconia ceramic systems and compare them with those of the bovine dentin and enamel/dentin structures. MATERIALS AND METHODS: 3Y-TZP and 5Y-PSZ zirconia ceramic systems were evaluated. A 0.5-mm-thick 3Y-TZP (3Y-NC.5), 0.5-mm-thick (5Y-NC.5), and 1.4-mm-thick (5Y-C.14) were used. A 0.5-mm-thick dentin specimens and 1.4-mm-thick enamel/dentin specimens (n = 5) were obtained from anterior bovine maxillary teeth. Scattering, absorption, transmittance, and albedo coefficient were calculated using Kubelka-Munk's model. Data were statistically analyzed using Kruskal-Wallis and Mann-Whitney tests (p < 0.001), and goodness-of-fit coefficient (GFC). Relative translucency parameter differences were evaluated using translucency thresholds. RESULTS: Reflectance, scattering, absorption, and transmittance properties were wavelength dependent. Good matches (GFC ≥ 0.999) in spectral reflectance were observed between 0.5-mm-thick dentin and 1.4-mm-thick enamel/dentin, and 3Y-NC.5 and 5Y-NC.5. Scattering was the main optical extinction process during light interaction with zirconia and dental structures, as indicated by albedo coefficient. Translucency differences were acceptable only for 3Y-NC.5 and the dentin structure, and 5Y-C.14 and the enamel/dentin structure. CONCLUSIONS: Optical properties of 3Y-TZP and 5Y-PSZ dental zirconia differed from each other and from bovine dental structures. Nevertheless, 3Y-TZP showed similar relative translucency parameter to bovine dentin. CLINICAL SIGNIFICANCE: To achieve the best esthetic results in restorative dentistry, it is crucial for clinicians to know about the optical properties of 3Y-TZP and 5Y-PSZ and to be able to compare these properties with those of dental structures.

Flexural strength and translucency of barium-silicate-filled resin nanoceramics for additive manufacturing.

OBJECTIVE: This in vitro study aimed to evaluate the flexural strength (FS) and translucency parameter (TP) of resin nanoceramics (RNCs) with barium silicate for additive manufacturing. MATERIALS AND METHODS: An RNC slurry was prepared by mixing a barium silicate filler and resin monomer. For the FS tests, specimens with three filler contents (0, 50, and 63 wt%) were designed according to ISO6872 for dental ceramics and ISO10477 for dental polymers. These specimens were then formed into discs with thicknesses of 1 and 2 mm for TP measurement. RESULTS: In the specimens prepared according to ISO6872, the FS increased significantly depending on the filler content. However, in the case of ISO10477, there was no significant difference between the FSs of the specimens with 0 and 50 wt% filler contents. The increase in thickness affected translucency, and the lowest translucency was obtained at a filler content of 63 wt%. The filler distribution was dense in the specimen with 63 wt% filler and uniform but relatively sparse in the specimen with 50 wt% filler. More voids were observed in the specimen with 63 wt% filler. The thickness and filler content of the specimen affected its TP. The TP of the specimen with 63 wt% filler was similar to that of human enamel. CONCLUSION: The FS was significantly higher at a filler content of 63 wt%. The lowest translucency was obtained at a filler content of 63 wt% for all tested thicknesses. CLINICAL SIGNIFICANCE: Increasing the filler content was advantageous for the mechanical properties of the RNCs. A high filler content led to low translucency in the RNCs. Therefore, the esthetics of human teeth can be reproduced if layering according to the filler content is performed in areas where esthetic characteristics are required.

Stainability and translucency of potassium aluminum sulfate applied computer-aided design and computer-aided manufacturing materials after coffee thermocycling.

OBJECTIVE: The purpose of this in vitro study was to evaluate the effect of potassium aluminum sulfate (alum) application on the stainability and translucency of computer-aided design and computer-aided manufacturing (CAD-CAM) materials after coffee thermocycling (CTC). MATERIALS AND METHODS: Disk-shaped specimens (Ø10 × 1 mm; N = 200) were fabricated by using additively (Crowntec [CT] and Varseo Smile Crown Plus [VS]) and subtractively manufactured (Brilliant Crios [RCR], CEREC Block [FC], and Vita Enamic [VE]) CAD-CAM materials and polished. All specimens were randomly divided into two groups as alum applied and control (n = 10). All specimens were then subjected to CTC (10,000 cycles at 5-55°C) and color coordinates were measured at each time interval. Color differences (ΔE00 ) and relative translucency parameters (RTPs) were calculated and the data were statistically analyzed (a = 0.05). RESULTS: Among tested time intervals, alum applied specimens had their lowest ΔE00 after alum application (p ≤ 0.006), except for FC (p = 0.177). In addition, alum applied RCR had lower ΔE00 values than its control specimens (p = 0.029). Alum applied specimens had their lowest RTP after CTC (p < 0.001) and alum application decreased the RTP of CT (p = 0.010). CTC reduced the RTP of all materials in control groups (p < 0.001). Alum applied CT had higher RTP than its control specimens (p = 0.049). CONCLUSIONS: Alum application's effect on color change varied depending on the material and alum mostly resulted in clinically acceptable changes in translucency. CTC led to unacceptable color and translucency changes based on previously reported threshold values. CLINICAL SIGNIFICANCE: Optical properties of CAD-CAM materials and the sustainability of these properties over time is critical for longevity. Alum may improve the color stability of reinforced composite resin when subjected to long-term coffee consumption.

Effect of polishing and bleaching on color, whiteness, and translucency of CAD/CAM monolithic materials.

OBJECTIVE: To evaluate the effect of polishing and bleaching on the recovery of lightness, color, whiteness, and relative translucency parameter (RTP) in CAD/CAM materials and changes in these properties when another staining in coffee was conducted after the treatments. MATERIALS AND METHODS: Disks of Lava Ultimate (LU), Vita Enamic (VE), IPS Empress CAD (EMP), IPS e.max CAD (EMAX), and Vita Suprinity (VS) were (1) not treated (control), (2) polished with Proxyt or (3) Ceramisté, (4) bleached with Opalescence PF or (5) Whiteness HP Blue, and (6) air polished with Clinpro Prophy Powder. CIE L*a*b* color coordinates were registered at baseline (R0), after staining with coffee for 30 min daily for 36.5 days and treatment (R1), and after another staining (R2). Differences (R1-R0 and R2-R0) in lightness (ΔL00), color (ΔE00), RTP (ΔRTP00), and whiteness (ΔWID) were evaluated by mixed repeated measures ANOVA and 95% confidence intervals (α = 0.05) and interpreted in function of their respective 50:50% PT and AT thresholds. Topography was evaluated by scanning electron microscopy (SEM). RESULTS: In LU, Opalescence PF and Proxyt decreased Δ L 00 R 1 - R 0 $$ {\Delta L}_{00\left({R}_1\hbox{--} {R}_0\right)} $$ , Δ E 00 R 1 - R 0 $$ {\Delta E}_{00\left({R}_1\hbox{--} {\mathrm{R}}_0\right)} $$ , and ΔWI D R 1 - R 0 $$ {\Delta \mathrm{WI}}_{\mathrm{D}\left({R}_1\hbox{--} {R}_0\right)} $$ and showed lower Δ L 00 R 2 - R 0 $$ {\Delta L}_{00\left({R}_2\hbox{--} {R}_0\right)} $$ , Δ E 00 R 2 - R 0 $$ {\Delta E}_{00\left({R}_2\hbox{--} {R}_0\right)} $$ , and ΔWI D R 2 - R 0 $$ {\Delta \mathrm{WI}}_{\mathrm{D}\left({R}_2\hbox{--} {R}_0\right)} $$ . In VE, all treatments decreased Δ L 00 R 1 - R 0 $$ {\Delta L}_{00\left({R}_1\hbox{--} {R}_0\right)} $$ , Δ E 00 R 1 - R 0 $$ {\Delta E}_{00\left({R}_1\hbox{--} {R}_0\right)} $$ , and ΔWI D R 1 - R 0 $$ {\Delta \mathrm{WI}}_{\mathrm{D}\left({R}_1\hbox{--} {R}_0\right)} $$ , whereas Δ L 00 R 2 - R 0 $$ {\Delta L}_{00\left({R}_2\hbox{--} {R}_0\right)} $$ , Δ E 00 R 2 - R 0 $$ {\Delta E}_{00\left({R}_2\hbox{--} {R}_0\right)} $$ , and ΔWI D R 2 - R 0 $$ {\Delta \mathrm{WI}}_{\mathrm{D}\left({R}_2\hbox{--} {R}_0\right)} $$ were lower in Opalescence PF than in the control group. In both moments, ΔE00 and ΔWID in EMP (also ΔL00) and EMAX were higher in Opalescence PF than in the control group, from which the other treatments did not differ in R1-R0. In EMP, Δ E 00 R 2 - R 0 $$ {\Delta E}_{00\left({R}_2\hbox{--} {R}_0\right)} $$ in Whiteness HP Blue (also Δ L 00 R 2 - R 0 $$ {\Delta L}_{00\left({R}_2\hbox{--} {R}_0\right)} $$ ) and Proxyt were also higher in comparison to the control group and in VS, Ceramisté decreased Δ L 00 R 1 - R 0 $$ {\Delta L}_{00\left({R}_1\hbox{--} {R}_0\right)} $$ , Δ E 00 R 1 - R 0 $$ {\Delta E}_{00\left({R}_1\hbox{--} {R}_0\right)} $$ , and Δ R T P 00 R 1 - R 0 $$ \varDelta RT{P}_{00\left({R}_1\hbox{--} {R}_0\right)} $$ , whereas Opalescence PF increased ΔRTP 00 R 1 - R 0 $$ {\Delta \mathrm{RTP}}_{00\left({R}_1\hbox{--} {R}_0\right)} $$ . Δ E 00 R 2 - R 0 $$ {\Delta E}_{00\left({R}_2\hbox{--} {R}_0\right)} $$ of Ceramisté and ΔWI D R 2 - R 0 $$ {\Delta \mathrm{WI}}_{\mathrm{D}\left({R}_2\hbox{--} {R}_0\right)} $$ and Δ R T P 00 R 2 - R 0 $$ \varDelta RT{P}_{00\left({R}_2\hbox{--} {R}_0\right)} $$ of Proxyt were lower than those of the control group. CONCLUSIONS: The most suitable treatment to recover the lightness, color, whiteness, and RTP without changing these properties after another coffee exposure is material-dependent. CLINICAL SIGNIFICANCE: Although the effectiveness of the treatment was material-dependent, Proxyt was the only treatment that promoted clinically acceptable changes for both LU and VE, while for purely ceramic materials, this condition was observed with Ceramisté and Clinpro Prophy Powder.

Effect of coffee staining and simulated oral hygiene methods on the color and translucency of a nanoceramic resin.

OBJECTIVE: Evaluate the color and translucency of a nanoceramic resin subjected to hygiene practices and immersion in coffee over time. MATERIALS AND METHODS: Specimens (n = 80, HT and LT, 0.5-mm thick) of a nanoceramic resin were obtained and were divided in groups according to the simulated oral hygiene: no intervention (NT), brushing with an electric brush and water (BN), brushing with an electric brush and toothpaste for 10 s (BT), and immersion in mouthwash for 30 s (MW). Oral hygiene practices were repeated after staining in coffee solution for 15, 48, 336, 1440, 8640, and 35,040 min. Spectral wavelengths were recorded with a spectrophotometer at each time. ∆E00, ∆L', ∆C', ∆H', and TP00 were calculated by CIEDE2000 and were evaluated by 2-way ANOVA, repeated measures ANOVA, and Tukey's HSD test (α = 0.05). RESULTS: ANOVA showed significance among factors for ΔE00 (p < 0.05), with higher ΔE00 for NT-HT (11.7) and NT-LT (11.2). After T6 (2-year simulation), the lowest values were found for BT-HT (5.3) and BT-LT (4.9). All groups showed a reduction in lightness and translucency and increased chroma and hue. However, the smallest variations were found in the BT groups (p < 0.05). CONCLUSIONS: Brushing with toothpaste effectively minimized the color change of NCRs caused by coffee staining. CLINICAL SIGNIFICANCE: Oral hygiene practices, such as brushing with toothpaste, might be important to minimize staining of nanoceramic resin restorations, especially in patients who frequently consume coffee.

Masking capacity of minimally invasive lithium disilicate restorations on discolored teeth-The impact of ceramic thickness, the material's translucency, and the cement color.

OBJECTIVES: To evaluate minimally invasive restorations' capacity to mask discolored teeth and explore the impact of ceramic thickness, translucency, and cement color. MATERIALS AND METHODS: Twenty-four assessment pairs of naturally colored and discolored bovine dentin samples were formed, using lithium disilicate specimens in six different thicknesses (0.3-0.8 mm), two different translucencies (high, low), and two cements (transparent, tooth-colored). Evaluators assessed the color differences in each assessment pair, and the threshold for detecting a color difference was determined using sequential testing and the Bonferroni-Holm method. RESULTS: A thickness of 0.6 mm effectively masked color differences using high translucent ceramic with transparent cement, detectable differences were still observed at 0.7/0.8 mm. A threshold thickness of 0.4 mm was seen using high translucent ceramic and tooth-colored cement, with color differences still discernible at 0.5 and 0.8 mm. A threshold thickness of 0.4 mm was detected using low translucent ceramic and transparent cement, while detectable differences persisted at 0.5, 0.7, and 0.8 mm. A 0.5 mm threshold thickness was observed when using low translucent ceramic and tooth-colored cement, and no detectable color differences were detected beyond this thickness. CONCLUSIONS: Masking can be achieved with a thickness of 0.4-0.5 mm using a low translucent material and tooth-colored cement. CLINICAL SIGNIFICANCE: Understanding the impact of ceramic thickness, translucency, and cement color can aid clinicians in making informed decisions for achieving the best esthetic outcomes while preserving tooth structure. Effective masking can be accomplished with ceramic thicknesses starting at 0.4 mm, especially when employing a low translucent material and tooth-colored cement. However, clinicians should be aware that discolorations may still be detectable in certain scenarios when using minimally invasive lithium disilicate restorations.