Possibilities of 3D printer Rapidshape D30 for manufacturing of cubic samples

The purpose of the present paper is to establish experimentally the possibilities of the 3D printer Rapidshape D30 for the manufacturing of standard cubic samples from different types of monomers and to evaluate their geometrical accuracy and roughness.Standard cubic samples with dimensions 5mm х 5mm х 5mm were printed from all the materials, given by the producer, in two ways of dimensional orientation according to the base – horizontally and inclined at 45о. They were manufactured with 3D printer Rapidshape D30, working on a stereolithography principle with LED light.It was established that:❖❖ The samples, made of NextDent Surgical Guide, have the highest dimensional accuracy and the lowest deviation interval in both ways of placement. This polymer is characterized with the highest thickness of the polymerization layer – 0.100 mm, but it is transparent, thus ensuring the entire polymerization throughout the depth of the whole layer. NextDent C+B, intended for manufacturing of temporary crowns and bridges, occupies a middle position in comparison to the other 6 materials.❖❖ Nearly in all the materials the surface roughness of the cube with horizontal placement is lower than that of the cube printed inclined (average values of Ra 0.46-2.69μm and Ra 1.74-2.77, respectively).❖❖ In 3D printing the surface roughness depends on the thickness of the polymerization layer and the inclination to the printing direction. The thicker the polymerization layer and the larger the slope, the higher the surface roughness

Investigation of the dental technicians’ readiness to manufacture dental prostheses using digital technologies

Introduction: Modern digital technologies allow us to generate a virtual model of the patient and to design his/her smile.  The future definitely belongs to the digital technologies because they offer a reliable, predictable and highly esthetic manner of treatment.Aim: The aim of the present study is to investigate the dental technicians' readiness to manufacture dental prostheses using digital technologies.Materials and Methods: A total of 159 respondents - practicing dental technicians and   students - were surveyed using an online survey. The survey was conducted via a social network platform.Results were processed with SPSS v. 20 using variational, comparative and correlation analyses. Results: Over 50% of the respondents have indicated that they use different types of digital technologies in their practice, the main reason being that the construction time is shortened and that the accuracy is improved (85.20%). There is a correlation between the length work experience and the use of new technologies (p<0.05), with younger specialists being the ones who primarily use modern technology. Young specialists are willing to invest in the purchase of modern equipment and to attend additional courses on working with it.Conclusion: Despite the variety of methods for recreating the prosthetic field when manufacturing prosthetic constructions, a trend towards full digitalization of the process is observed.The results from the conducted analyses show that digitalization is being increasingly used by young specialists (CAD planning and software application – 78.40%), who prefer it because it increases accuracy and shortens production time (85.40%)

3D-printing in contemporary prosthodontic treatment

The purpose of the present paper is to make a review of the applications for 3D-printing in contemporary prosthetic treatment as this modern technology has become widely spread not only in the industry but in medicine and dentistry, too. It is a form of additive manufacturing technology where a three-dimensional object is created by laying down successive layers of material

Motor development in infancy and spine shape in early old age: findings from a British birth cohort study

Spine shape changes dramatically in early life, influenced by attainment of developmental milestones such as independent walking. Whether these associations persist across life is unknown. Therefore, we investigated associations between developmental milestones and spine shape, as determined using statistical shape models (SSMs) of lumbar spine from DXA scans in 1327 individuals (688 female) at 60‐64y in the MRC National Survey of Health and Development. Lumbar lordosis angle (L4 inferior endplate to T12 superior endplate) was measured using the two‐line Cobb method. In analyses adjusted for sex, height, lean and fat mass, socioeconomic position and birthweight, later walking age was associated with greater lordosis described by SSM1 (regression coefficient 0.023, 95%CI 0.000‐0.047, p=0.05) and direct angle measurement. Modest associations between walking age and less variation in anterior‐posterior vertebral size caudally (SSM6) were also observed (0.021, 95%CI ‐0.002‐0.044, p=0.07). Sex interactions showed that later walking was associated with larger relative vertebral anterior‐posterior dimensions in men (SSM3; ‐0.043, 95%CI ‐0.075‐0.01, p=0.01) but not women (0.018, 95%CI ‐0.0007‐0.043, p=0.17). Similar associations were observed between age at independent standing and SSMs but there was little evidence of association between sitting age and spine shape. Unadjusted associations between walking age and SSMs 1 and 6 remained similar after adjustment for potential confounders and mediators. This suggests that these associations may be explained by altered mechanical loading of the spine during childhood growth, although other factors could contribute. Early life motor development, particularly walking, may have a lasting effect on features of spine morphology with clinical significance

Associations between body mass index across adult life and hip shapes at age 60 to 64:Evidence from the 1946 British birth cohort

Funding: The NSHD is funded by the UK Medical Research Council. SGM, RC, RJH and DK are supported by the UK Medical Research Council (Programme codes: MC_UU_12019/1, MC_UU_12019/2 and MC_UU_12019/4). This project was funded by the UK Medical Research Council (Grant MR/L010399/1) which supported SGM, AVP and FRS. The funders of the study had no role in study design, data collection, data analysis, data interpretation or writing of this manuscript. Acknowledgements: We thank Dr. Michael Machin for his valuable assistance obtaining the images and the University of Aberdeen Data Management Team for programming support for ‘Shape’. The authors are grateful to NSHD study members who took part in the clinic data collection for their continuing support. We thank members of the NSHD scientific and data collection teams at the following centres: MRC Unit for Lifelong Health and Ageing; Wellcome Trust (WT) Clinical Research Facility (CRF) Manchester; WTCRF and Medical Physics at the Western General Hospital in Edinburgh; WTCRF and Department of Nuclear Medicine at University Hospital Birmingham; WTCRF and the Department of Nuclear Medicine at University College London Hospital; CRF and the Department of Medical Physics at the University Hospital of Wales; CRF and Twin Research Unit at St Thomas' Hospital London. Data used in this publication are available to bona fide researchers upon request to the NSHD Data Sharing Committee via a standard application procedure. Further details can be found at: http://www.nshd.mrc.ac.uk/data; doi: http://dx.doi.org/10.5522/NSHD/Q102; doi: http://dx.doi.org/10.5522/NSHD/Q102A.Peer reviewedPublisher PD

Age at onset of walking in infancy is associated with hip shape in early old age

Bones’ shapes and structures adapt to the muscle and reaction forces they experience during everyday movements. Onset of independent walking, at approximately 12 months, represents the first postnatal exposure of the lower limbs to the large forces associated with bipedal movements, and, accordingly, earlier walking is associated with greater bone strength. However, associations between early life loading and joint shape have not been explored. We therefore examined associations between walking age and hip shape at age 60-64y in 1423 individuals (740 women) from the MRC National Survey of Health and Development, a nationally-representative British birth cohort. Walking age in months was obtained from maternal interview at age 2y. Ten modes of variation in hip shape (HM1-HM10), described by statistical shape models, were ascertained from dual-energy X-ray absorptiometry (DXA) images. In sex-adjusted analyses, earlier walking age was associated with higher HM1 and HM7 scores; these associations were maintained after further adjustment for height, body composition and socioeconomic position. Earlier walking was also associated with lower HM2 scores in women only, and lower HM4 scores in men only. Taken together, this suggests that earlier walkers have proportionately larger (HM4) and flatter (HM1,4) femoral heads, wider (HM1,4,7) and flatter (HM1, 7) femoral necks, smaller neck-shaft angle (HM1,4), anteversion (HM2,7) and development of osteophytes (HM1). These results suggest that age at onset of walking in infancy is associated with variations in hip shape in older age. Early walkers have a larger femoral head and neck and smaller neck-shaft angle; these features are associated with reduced hip fracture risk, but also represent an osteoarthritic-like phenotype. Unlike results of previous studies of walking age and bone mass, associations in this study were not affected by adjustment for lean mass suggesting that associations may relate directly to skeletal loading in early life when joint shape changes rapidly. This article is protected by copyright. All rights reserve

Social factors influencing Russian male alcohol use over the life course: a qualitative study investigating age based social norms, masculinity, and workplace context

The massive fluctuations occurring in Russian alcohol-related mortality since the mid-1980s cannot be seen outside of the context of great social and economic change. There is a dearth of qualitative studies about Russian male drinking and especially needed are those that address social processes and individual changes in drinking. Conducted as part of a longitudinal study on men’s alcohol consumption in Izhevsk, this qualitative study uses 25 semi-structured biographical interviews with men aged 33–60 years to explore life course variation in drinking. The dominant pattern was decreasing binge and frequent drinking as men reached middle age which was precipitated by family building, reductions in drinking with work colleagues, and health concerns. A minority of men described chaotic drinking histories with periods of abstinence and heavy drinking. The results highlight the importance of the blue-collar work environment for conditioning male heavy drinking in young adulthood through a variety of social, normative and structural mechanisms. Post-Soviet changes had a structural influence on the propensity for workplace drinking but the important social function of male drinking sessions remained. Bonding with workmates through heavy drinking was seen as an unavoidable and essential part of young men’s social life. With age peer pressure to drink decreased and the need to perform the role of responsible breadwinner put different behavioural demands on men. For some resisting social pressure to drink became an important site of self-determination and a mark of masculine maturity. Over the lifetime the place where masculine identity was asserted shifted from the workplace to the home, which commonly resulted in a reduction in drinking. We contribute to existing theories of Russian male drinking by showing that the performance of age-related social roles influences Russian men’s drinking patterns, drinking contexts and their attitudes. Further research should be conducted investigating drinking trajectories in Russian men

Mitochondrial physiology

As the knowledge base and importance of mitochondrial physiology to evolution, health and disease expands, the necessity for harmonizing the terminology concerning mitochondrial respiratory states and rates has become increasingly apparent. The chemiosmotic theory establishes the mechanism of energy transformation and coupling in oxidative phosphorylation. The unifying concept of the protonmotive force provides the framework for developing a consistent theoretical foundation of mitochondrial physiology and bioenergetics. We follow the latest SI guidelines and those of the International Union of Pure and Applied Chemistry (IUPAC) on terminology in physical chemistry, extended by considerations of open systems and thermodynamics of irreversible processes. The concept-driven constructive terminology incorporates the meaning of each quantity and aligns concepts and symbols with the nomenclature of classical bioenergetics. We endeavour to provide a balanced view of mitochondrial respiratory control and a critical discussion on reporting data of mitochondrial respiration in terms of metabolic flows and fluxes. Uniform standards for evaluation of respiratory states and rates will ultimately contribute to reproducibility between laboratories and thus support the development of data repositories of mitochondrial respiratory function in species, tissues, and cells. Clarity of concept and consistency of nomenclature facilitate effective transdisciplinary communication, education, and ultimately further discovery