Color assessment of resin composite by using cellphone images compared with a spectrophotometer

de Bragança Rafaella Mariana Fontes,Moraes Rafael Ratto,Faria-e-Silva André Luis 대한치과보존학회 2021 Restorative Dentistry & Endodontics Vol.46 No.2

Objectives: This study assessed the reliability of digital color measurements using images of resin composite specimens captured with a cellphone. Materials and Methods: The reference color of cylindrical specimens built-up with the use of resin composite (shades A1, A2, A3, and A4) was measured with a portable spectrophotometer (CIELab). Images of the specimens were obtained individually or pairwise (compared shades in the same photograph) under standardized parameters. The color of the specimens was measured in the images using RGB system and converted to CIELab system using image processing software. Whiteness index (WID) and color differences (ΔE00) were calculated for each color measurement method. For the cellphone, the ΔE00 was calculated between the pairs of shades in separate images and in the same image. Data were analyzed using 2-way repeated-measures analysis of variance (α = 0.05). Linear regression models were used to predict the reference ΔE00 values of those calculated using color measured in the images. Results: Images captured with the cellphone resulted in different WID values from the spectrophotometer only for shades A3 and A4. No difference to the reference ΔE00 was observed when individual images were used. In general, a similar ranking of ΔE00 among resin composite shades was observed for all methods. Stronger correlation coefficients with the reference ΔE00 were observed using individual than pairwise images. Conclusions: This study showed that the use of cellphone images to measure the color difference seems to be a feasible alternative providing outcomes similar to those obtained with the spectrophotometer.

Effects of surrounding and underlying shades on the color adjustment potential of a single-shade composite used in a thin layer

Barros Mariana Silva,Silva Paula Fernanda Damasceno,Santana Márcia Luciana Carregosa,Bragança Rafaella Mariana Fontes,Faria-e-Silva André Luis 대한치과보존학회 2023 Restorative Dentistry & Endodontics Vol.48 No.1

Objectives This study aimed to evaluate the surrounding and underlying shades’ effect on the color adjustment potential (CAP) of a single-shade composite used in a thin layer. Materials and Methods Cylinder specimens (1.0 mm thick) were built with the Vittra APS Unique composite, surrounded (dual specimens) or not (simple specimens) by a control composite (shade A1, A2, or A3). Simple specimens were also built only with the control composites. Each specimen’s color was measured against white and black backgrounds or the simple control specimens with a spectrophotometer (CIELAB system). The whiteness index for dentistry (WID) and translucency parameters (TP00) were calculated for simple specimens. Differences (ΔE00) in color between the simple/dual specimens and the controls were calculated. The CAP was calculated based on the ratios between data from simple and dual specimens. Results The Vittra APS Unique composite showed higher WID and TP00 values than the controls. The highest values of ΔE00 were observed among simple specimens. The color measurements of Vittra APS Unique (simple or dual) against the control specimens presented the lowest color differences. Only surrounding the single-shade composite with a shaded composite barely impacted the ΔE00. The highest CAP values were obtained using a shaded composite under simple or dual specimens. Conclusions The CAP of Vittra APS Unique was strongly affected by the underlying shade, while surrounding this composite with a shaded one barely affected its color adjustment.

Echocardiographic Assessment of Right Ventriculo-arterial Coupling: Clinical Correlates and Prognostic Impact in Heart Failure Patients Undergoing Cardiac Resynchronization Therapy

Bruno Bragança,Maria Trêpa,Raquel Santos,Inês Silveira,Marta Fontes Oliveira,Maria João Sousa,Hipólito Reis,Severo Torres,Mário Santos 한국심초음파학회 2020 Journal of Cardiovascular Imaging (J Cardiovasc Im Vol.28 No.2

BACKGROUND: Right ventriculo-arterial coupling (RV-PA) can be estimated by echocardiography using the ratio between tricuspid annular plane systolic excursion (TAPSE) and pulmonary artery systolic pressure (PASP) and it has prognostic value in the general heart failure (HF) population. We aimed to study the clinical correlates and prognostic value of RV-PA in HF patients undergoing cardiac resynchronization therapy (CRT). METHODS: We retrospectively studied 70 HF patients undergoing CRT implantation. RESULTS: RV-PA coupling was estimated by TAPSE/PASP ratio using baseline echocardiography. Non-response to CRT was defined as improvement of left ventricular ejection fraction < 5% in a follow-up echo 6-12 months after CRT. Those with lower TAPSE/PASP ratios (worse RV-PA coupling) had higher NT-proBNP concentrations and increased E/e′ ratio. TAPSE/PASP ratio and PASP, but not TAPSE, predicted nonresponse to CRT with TAPSE/PASP ratio showing the best discriminative ability with a sensitivity of 76% and specificity of 71%. Among these parameters, PASP independently predicted all-cause mortality. CONCLUSIONS: RV-PA coupling estimated by TAPSE/PASP ratio was associated with established prognostic markers in HF. It numerically outperformed PASP and TAPSE in predicting the response to CRT. Our data suggest that this simple and widely available echocardiographic parameter conveys significant pathophysiological and prognostic meaning in HF patients undergoing CRT.

Hybrid Wire-Arc Additive Manufacturing of Conformal Cooling Channels: A Feasibility Study

João P. M. Pragana,Ivo M. F. Bragança,Carlos M. A. Silva,Paulo A. F. Martins 한국정밀공학회 2023 International Journal of Precision Engineering and Vol.10 No.1

This paper investigates the feasibility of hybridizing wire-arc additive manufacturing with metal forming to create conformal cooling channels in moulds for hot material processing. An axisymmetric mould is used as a prototype test case and plastic deformation by flaring of the additively deposited inner tubular element is utilized to create the overhangs for connecting with the outer tubular element that are needed to fabricate the cooling channels. Finite element modelling of plastic deformation by flaring of the additively deposited material is carried out to identify the different modes of deformation and to determine the maximum allowable radius of the overhangs. Results show that the proposed hybridization of wire-arc additive manufacturing with plastic deformation by flaring adds flexibility to the design and fabrication of conformal channels in the as-built mould by eliminating the use of support structures and avoiding the use of complex deposition strategies. Finishing of the functional surfaces of the as-built mould by turning ensures the required accuracy and surface quality.

Integration of Forming Operations on Hybrid Additive Manufacturing Systems Based on Fusion Welding

João P. M. Pragana,Valentino A. M. Cristino,Ivo M. F. Bragança,Carlos M. A. Silva,Paulo A. F. Martins 한국정밀공학회 2020 International Journal of Precision Engineering and Vol.7 No.3

This paper is focused on the integration of metal forming operations in hybrid systems that combine additive manufacturing (AM) by gas metal wire arc and subtractive manufacturing by machining. The investigation is carried out in AISI 316L stainless steel wire and draws from tensile testing to incremental sheet forming of truncated conical shapes. Commercial sheets from the same material are utilized for comparison purposes. Thickness measurements, digital image correlation (DIC), circle grid analysis (CGA) and microstructural and scanning electron microscopy (SEM) observations are carried out to understand how diff erent is the mechanical behaviour of the deposited metal from that of commercial metal sheets and how signifi cant is the infl uence of the deposited metal microstructure on its overall formability. Results confi rm that integration of metal forming operations in hybrid AM routes is feasible despite the formability of deposited metal being smaller than that of the commercial metal sheets due to the strong anisotropy induced by the dendritic based microstructure of the deposited metal. Incremental forming of two deposited parts also allows concluding that integration of metal forming operations in hybrid AM systems is a step towards green and sustainable manufacturing by extending their fi eld of applicability to the fabrication of complex ready-to-use parts requiring combination of diff erent processes.

The effectiveness of the supplementary use of the XP-endo Finisher on bacteria content reduction: a systematic review and meta-analysis

Oliveira Ludmila Smith de Jesus,Bragança Rafaella Mariana Fontes de,Sarkis-Onofre Rafael,Faria-e-Silva André Luis 대한치과보존학회 2021 Restorative Dentistry & Endodontics Vol.46 No.3

Objectives: This systematic review evaluated the efficacy of the supplementary use of the XP-endo Finisher on bacteria content reduction in the root canal system. Materials and Methods: In-vitro studies evaluating the use of the XP-endo Finisher on bacteria content were searched in four databases in July 2020. Two authors independently screened the studies for eligibility. Data were extracted, and risk of bias was assessed. Data were meta-analyzed by using random-effects model to compare the effect of the supplementary use (experimental) or not (control) of the XP-endo Finisher on bacteria counting reduction, and results from different endodontic protocols were combined. Four studies met the inclusion criteria while 1 study was excluded from the meta-analysis due to its high risk of bias and outlier data. The 3 studies that made it to the meta-analysis had an unclear risk of bias for at least one criterion. Results: No heterogeneity was observed among the results of the studies included in the meta-analysis. The study excluded from the meta-analysis assessing the bacteria counting deep in the dentin demonstrated further bacteria reduction upon the use of the XP-endo Finisher. Conclusions: This systematic review found no evidence supporting the supplementary use of the XP-endo Finisher on further bacteria counting the reduction in the root canal.