Search results for "enamel"
showing 10 items of 277 documents
The blue enamels in the baroque decorations of the churches of Palermo, Sicily: Fe2+-coloured glasses from lime kilns
2009
Deep blue glasses coloured by octahedral Fe 2+ cations are often reported as textbook examples of blue pigmentation. However, despite the possibility of laboratory synthesis under reducing conditions, to date there are no well-reported occurrences of their production and use in the past. A thorough historical, ethnographic, mineralogical, and chemico-physical investigation of the 'smaltini di calcara' from several baroque churches in Palermo, Sicily, has revealed that the blue enamels widely used for altar decorations in the 17th and 18th centuries are actually a unique case of ancient blue glasses pigmented by divalent iron cations in distorted octahedral coordination. This mixed-alkali gl…
Nutrition-related health problems in a wealthy 17-18th century German community in Jelgava, Latvia.
2012
The aim of this research is to assess the presence of stress in a high status German population from Jelgava, Latvia. The skeletal material used in this study came from a recently excavated church cemetery, with most of the burials dating to the 17-18th centuries. In total, 108 individuals (80 adults and 28 non-adults) were analysed for evidence of scurvy, rickets/osteomalacia and anaemia. The presence of scurvy and healed rickets/osteomalacia could not be confirmed in any adult individual. Among non-adults, a possible diagnosis of scurvy was considered in six individuals, and active rickets was suggested in two others. Cribra orbitalia in adult and non-adult individuals also argued for the…
Horse exploitation at the Late Upper Palaeolithic site of Oelknitz (Thuringia, Germany) with special reference to canine modifications
2012
Abstract The faunal assemblage from Structure 5 of the Magdalenian settlement Oelknitz (Thuringia, Germany) was analyzed. The fauna is dominated by horse. All stages of butchery from skinning to marrow extraction were performed within the horse assemblage. In addition to this, various stages of organic artifact production could be documented. Two fragmentary equid canine teeth were of particular interest. They are the only documented canines from Structure 5, which otherwise contained a large amount of teeth. Both canines show traces of human modification. They were cut out of the jaw while still in the alveole. On both canines, lateral incisions were performed at the cervix dentis and the …
Inferences of dietary preferences of Miocene squirrels (Xerinae, Sciuridae) from the Iberian Peninsula and Namibia using microwear analyses and ename…
2020
In this work, we compared microwear features and enamel thickness from upper molars (M1 and M2) of extinct Xerinae squirrels from the Miocene of Namibia (Vulcanisciurus sp) and the Iberian Peninsula (Atlantoxerus nov. sp. and Heteroxerus rubricati). We also examined the microwear from young and adult specimens of one extant squirrel, Atlantoxerus getulus, to compare it with the extinct species. Both, the microwear features and enamel thickness showed that the Miocene African species presented a more abrasive diet than the Iberian ones.
Iugalia vetustissima. Argenti, avori e smalti nel Tesoro della Chiesa Madre (XIV-XV secolo)
2016
Nel contributo si approfondisce lo studio di oggetti liturgici già noti (due calici di argentieri e smaltisti siciliani toscaneggianti, di fine XIV-inizi XV secolo il primo, del 1429 il secondo; un reliquiario di argentiere genovese e maestranze veneziane della prima metà del XV secolo), mentre si portano per la prima volta all'attenzione degli studiosi del settore altri tre manufatti: una croce da tavolo, già stauroteca, in argento, opera siciliana della metà del XV secolo, su cui si innestano due statuette protogotiche a tutto tondo di Dolenti in avorio o osso, forse dovute a maestranza iberica di fine XIII-inizi XIV secolo, ed un Crocifisso metallico su croce lignea del XVIII secolo; una…
Chemical composition of modern and fossil hippopotamid teeth and implications for paleoenvironmental reconstructions and enamel formation – Part 2: A…
2012
Abstract. For reconstructing environmental change in terrestrial realms the geochemistry of fossil bioapatite in bones and teeth is among the most promising applications. This study demonstrates that alkaline earth elements in enamel of Hippopotamids, in particular Ba and Sr are tracers for water provenance and hydrochemistry. The studied specimens are molar teeth from Hippopotamids found in modern and fossil lacustrine settings of the Western Branch of the East African Rift system (Lake Kikorongo, Lake Albert, and Lake Malawi) and from modern fluvial environments of the Nile River. Concentrations in enamel vary by ca. two orders of magnitude for Ba (120–9336 μg g−1) as well as for Sr (9–21…
A comparative quantitative & qualitative assessment in orthodontic treatment of white spot lesion treated with 3 different commercially available mat…
2019
Background To comparatively evaluate the esthetic improvement of white-spot lesions (WSLs) treated by: BiominF, CPP-ACP paste with fluoride & ICON resin infiltration, using Spectrophotometer & Diagnodent. Material and Methods The study was done using 72 sound permanent extracted premolars, divided into four groups (18 teeth per group). After taking the ethical approval the study was commenced. WSLs were created on human premolars and randomly assigned to four groups: Group A: Artificial Saliva, Group B: CPP-ACP with fluoride, Group C: BiominF, Group D: Resin infiltration (Icon). The color change (∆E) of each specimen was measured with a Spectrophotometer (VITA Easy Shade Compact), and fluor…
Structural and functional characterization of enamel pigmentation in shrews.
2013
Pigmented tooth enamel occurs in several vertebrate clades, ranging from mammals to fish. Although an iron compound is associated with this orange to red colored pigmentation, its chemical and structural organization within the enamel is unknown. To determine the nature of the iron compound, we investigated heavily pigmented teeth of the northern short-tailed shrew Blarina brevicauda using combined characterization techniques such as scanning and transmission electron microscopy and synchrotron X-ray diffraction. We found that the pigmentation of the enamel with an iron content of around 8wt% results from a close to amorphous magnetite phase deposited around the nm-sized enamel crystals. Fu…
Hydrogen Peroxide Diffusion through Enamel and Dentin
2018
The purpose of this study was to evaluate the in vitro diffusion of commercial bleaching products (hydrogen peroxide (HP) or carbamide peroxide (CP) based) with different application protocols. Human enamel-dentin discs were obtained and divided into 20 groups. Four commercial products based on HP (Pola Office+(PO), Perfect Bleach (PB), Norblanc Office-automix (NO), and Boost (BT)), and one based on CP (PolaDay CP (PD)), were evaluated with different application protocols (3 applications ×
Five-year results following treatment of intrabony defects with enamel matrix proteins and guided tissue regeneration
2004
Treatment with enamel matrix proteins (EMD) or guided tissue regeneration (GTR) has been shown to enhance periodontal regeneration. However, until now there are limited data on the long-term results following these treatment modalities.The aim of the present clinical study was to present the 5-year results following treatment of intrabony defects with EMD, GTR, combination of EMD and GTR, and open flap debridement (OFD).Forty-two patients, each of whom displayed one intrabony defect of a probing depth of at least 6 mm, were randomly treated with one of the four treatment modalities. The following parameters were evaluated prior to surgery, at 1 year and at 5 years after: plaque index, gingi…