The Influence of Dental Occlusion on Spectrophotometric Tooth Color Determinations

Background: Shade matching is a significant treatment step and a challenge for the clinical team with potentially high costs for color correction. Currently, in the United States, the majority of private dental practitioners use visual color matching, but a recent study has reported a high rate of mistakes of subjective color determination among graduate dentists. Objective: The aim of this retrospective study is to analyze whether a change in the oral background due to dental occlusion can influence tooth color determination. Methods: Volunteer dental students underwent spectrophotometric color assessment using the SpectroShade device. Two measurements were carried out (with the individuals’ occlusion closed and with the occlusion open) on 43 upper central and 58 lateral incisors. Association between colorimetric variables L*, a*, b* and ΔE00 and tooth width, length and tobacco usage were examined. Results: Slight changes in the CIELAB values between closed and open occlusions were found for both the gingival and the central sections as for the overall tooth area, with mean ΔL*=-1.24, Δa*=-1.77, Δb*=-1.42 and ΔE00=1,84. A larger difference was detected in the incisal area, with mean ΔL*=-2.99, Δa*=-1.76, Δb*=-2.83 and ΔE00=3.65. Conclusion: In conclusion, our study showed that dental occlusion does not play a significant role in tooth color matching determinations, even though attention to avoid overbite due to a maximum intercuspation should be made

Knowledge of emergency management of avulsed teeth among Italian dentists-questionnaire study and next future perspectives

(1) Background: In Italy, about one fourth of all schoolchildren experience a trauma to the permanent dentition. Management of avulsion trauma is challenging and requires adherence to clinical protocols. The aim of this study was to investigate the management knowledge of avulsed teeth among Italian dentists and to promote the guidelines’ dissemination through the use of new social media. (2) Methods: The survey was carried out during the COVID-19 lockdown in Italy (March–May 2020). The questionnaire was sent anonymously to a total of 600 dentists. The questionnaire consisted of two parts. Part A—demographic and professional data and Part B—management of traumatic avulsion. (3) Results: The response rate was 50.6% and the mean fraction of correct responses was 0.524. Issues related to the therapeutic management of avulsed teeth were shown to be not well understood by the respondents. Professionals with qualifications in dentistry and those who declared to know the guidelines responded better, while other demographic and professional factors were insignificant. (4) Conclusions: Italian dentists’ knowledge of the management of avulsion trauma should be improved. Educational programs and campaigns must be undertaken to improve their awareness and adherence to the Italian and international guidelines

The influence of uncertainty and unpredictability on logistics processes

Autorzy artykułu na podstawie teoretycznych rozważań nad zjawiskiem niepewności i nieprzewidywalności w logistyce, bazując na przeglądzie stanowisk i podejść badawczych, podjęli próbę usystematyzowania semantyki w podjętym problemie oraz wskazują na obszary logistyki szczególnie podatne na niepewność i nieprzewidywalność, uwypuklając aspekt transportu morskiego. Teoretyczne rozważania nad rolą niepewności w procesie logistycznym oraz nad relacjami między pojęciami niepewności i nieprzewidywalności stanową podstawę do koncepcyjnego podejścia do możliwości pomiaru niepewności w lądowo-morskim procesie logistycznym. Ten sposób ujęcia problemu pozwala na realizację podstawowego celu artykułu, którym jest wyznaczenie miejsca dla sytuacji niepewności w logistyce na płaszczyźnie efektywności wykorzystania czasu i związku z tym wydajności procesów logistycznych.The authors of the article on the basis of theoretical considerations on the phenomenon of uncertainty and unpredictability in logistics, based on a review of positions and research approaches, lead to attempts to systematize semantics in the taken problem and indicate the areas of logistics susceptible particularly to uncertainty and unpredictability. Theoretical considerations on the role of uncertainty in the logistics process and the relation between the concepts of uncertainty and unpredictability constitute the basis for a conceptual approach to the possibility of uncertainty’s measurement in the logistics process. The way of recognizing the problem realizes elementary aim of the article, which is to designate space for uncertainty in logistics at the area of efficiency of time and therefore productivity of logistics processes

Wsparcie logistyczne akcji ratunkowej w aspekcie minimalizacji śladu ekologicznego jako wymogu środowiskowego zrównoważonego rozwoju na przykładzie katastrofy naturalnej

Background: The aim of the considerations is to present the concept of the ecological footprint of logistic support for a rescue operation on the example of a natural disaster. Increasing pressure of environmental requirements placed on all logistic activities, including logistic support, justifies the attention drawn to the subject. Methods: Selecting a natural disaster - as a reference for the concept of the ecological footprint - constitutes an attempt to draw attention to the fact that logistic support for a rescue operation in the case of a natural disaster - apart from an unquestionably positive role - also negatively affects the environment, which should be exposed, and this will be manifested by creation of measuring and analysing instruments necessary within undertaken activities aimed at minimalization of the negative impact of logistic support on the environment. The ecological footprint can be considered to be such an instrument. Results: Based on the general formula of the ecological footprint and its methodology presented in "Working Guidebook to the National Footprint Accounts 2014", a formula of the ecological footprint of logistic support for a rescue operation on the example of a natural disaster was created. Conclusions: The assumptions of the concept of the ecological footprint of logistic support for a rescue operation on the example of a natural disaster were based on the assumptions of logistic support for a rescue operation and on the assumptions of the resource concept and external costs of logistic support for a rescue operation on the example of a natural disaster.Wstęp: Celem rozważań jest przedstawienie koncepcji śladu ekologicznego wsparcia logistycznego akcji ratunkowej na przykładzie katastrofy naturalnej. Coraz większa presja wymogów środowiskowych wywierana na wszelką działalność logistyczną, w tym również tą, w formie wsparcia logistycznego, uzasadnienia atencję dla podjętej problematyki. Metody: Wybór katastrofy naturalnej - jako płaszczyzny odniesienia koncepcji śladu ekologicznego - jest z kolei próbą zwrócenia uwagi, że wsparcie logistyczne akcji ratunkowej w sytuacji katastrofy naturalnej, oprócz bezsprzecznie pozytywnej roli, również oddziałuje negatywnie na środowisko, które należy eksponować, czego przejawem będzie tworzenie instrumentów pomiaru i analizy, niezbędnych przy podejmowaniu działań, mających na celu minimalizację negatywnego oddziaływania wsparcia logistycznego na środowisko. Ślad ekologiczny można uznać za taki instrument. Wyniki: W oparciu o ogólną formułę śladu ekologicznego oraz jej metodykę przedstawioną w "Working Guidebook to the National Footprint Accounts 2014", utworzono formułę śladu ekologicznego wsparcia logistycznego akcji ratunkowej na przykładzie katastrofy naturalnej. Wnioski: Założenia koncepcji śladu ekologicznego wsparcia logistycznego akcji ratunkowej na przykładzie katastrofy naturalnej oparto na założeniach wsparcia logistycznego akcji ratunkowej oraz na założeniach koncepcji zasobowej i kosztów zewnętrznych wsparcia logistycznego akcji ratunkowej na przykładzie katastrofy naturalnej

The Effect of Pt Content on the Scale Development on β-NiAl at Very Early Oxidation Stages

Very early stages of development of the oxide scale formed in air at 1150° on unmodified and containing varying amounts of Pt (5, 10 and 15 at.%) β-NiAl intermetallic compound were studied. The scale morphology was observed using scanning electron microscopy, while photoluminescence spectroscopy was applied to determine its phase composition with spatial resolution down to 1 μm. It was found that the scales were non-uniform in terms of their morphology and, to a lesser extent, of their phase composition. Pt additions resulted in earlier development of the α-Al2O3 oxide, which, based also on recently reported literature experimental and modelling results, may be attributed to the increased rate of the scale evolution. The possible direct effect of Pt on the phase transformation of unstable aluminium oxides into α-Al2O3 still needs to be verified as the complementary or alternative explanation. © 2017, Springer Science+Business Media New York

On the early stages of scale development on Ni - 22Al - 30Pt with and without Hf additions at 1150°C

Platinum modified Ni - Al-based alloys play an important role in the aeronautical industry as materials applied as Bond Coats (BCs) in thermal barrier coating systems (TBC), which provide protection against high temperature oxidation. Therefore, it is crucial for the assessment of the performance of the TBC to understand the oxidation behaviour of the Bond Coat material and the properties of the thermally grown oxide developing on it. This paper reports on the scale growth mechanism of Pt-modified γ′-Ni 3 Al-based alloys with and without Hf additions at the early stages of oxidation. Samples were oxidized at 1150°C for up to 50 min. The consecutive stages of the scale evolution were followed by a systematic approach using a two-stage oxidation treatment in atmospheres containing different amounts of 18O 2 oxygen isotope. The scale growth mechanism was followed with the aid of the in-depth analysis of elemental distribution, in particular of the oxygen isotopes, across the scale using secondary ion mass spectrometry (SIMS). The surface morphology of the scales was observed using scanning electron microscopy, while its local phase composition was determined using photoluminescence spectroscopy. In addition, the imaging SIMS was used to generate distribution maps of the oxygen isotopes. Because of the limited lateral resolution of the SIMS technique (down to 0.5 mm) they were conclusive only for the most prolonged exposures (50 min). Typical stages of scale evolution were observed for the growing scales: initially flat layers were formed, followed by more or less developed blade-like surface grains, phase-transformation-related cracks and round patches and, finally, ridges. The latter were only found on the Hf-free material. The scale growth mechanism evolved from an initially predominant outward growth mechanism towards an increasing contribution of the inward mechanism. The relative extents of the outward and inward growth mechanisms depended strongly on the surface fraction of patches and through-scale cracks. The phase composition analyses showed that cracks and patches are regions where the transient aluminas were preferentially transformed into the α-Al 2O 3 phase which is the required protective scale. The ridges formed in cracks essentially consisted of α-Al 2O 3. For the most of studied exposure periods both types of phases: transient aluminas and α-Al 2O 3 co-existed in the scales. The results obtained indicate that: (i) phase transformations occur locally and not simultaneously in the entire scale; (ii) Hf additions retard the phase transformation; (iii) the phase transformation is completed only on Hf-free material and not after oxidation for 50 min; (iv) the two-stage oxidation approach should be carefully applied to study the growth mechanism of evolving scales in which regions of different phase compositions develop