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Little dreams in glass and metal : enameling in America 1920 to the present
\"With one hundred and twenty-two works, ranging in date from 1920 to the present, made by more than ninety artists, Little Dreams reflects the diversity of modern and contemporary enameling in the United States. It also represents the wide variety of forms of formats artists have chosen to explore using this highly versatile medium. More than half the artists included in Little Dreams are women; at least twenty-eight studied or taught in Cleveland; fourteen were born abroad and came to this country in the 1930s to escape Nazi persecution and the impending war in Europe; many studied under the GI Bill after serving in the armed forces during World War II. While sixteen were based in California, others lived in disparate regions of the country from New England to the Pacific Northwest; many were accomplished in other media but chose enameling as their preferred vehicle; eight couples worked collaboratively; and many used enamel as but one tool in their multi-media compositions. The artists' themes are similarly diverse, ranging from traditional still lifes, genre scenes, and religious subjects to abstractions and powerfully evocative explorations of nature, culture, and memory. This impressive array of makers and their equally wide-ranging subjects reflect the dynamic state of enameling in this country in the last half of the twentieth century and the first decades of the twenty-first\"-- Foreword.
Book
Adhesive system containing Bioglass 45S5 particles in teeth affected by molar-incisor hypomineralization and quality of life impact: study protocol for a randomized clinical trial
Background
Molar-incisor hypomineralization (MIH) is a systemic condition characterized by a qualitative defect in the dental enamel. It primarily affects the first permanent molars and is often associated with the permanent incisors. Resin restorations in MIH-affected teeth consistently show worse results than those in normal teeth because of the ultrastructure of hypomineralized enamel, which compromises adhesion. The incorporation of bioactive particles into adhesives is a promising option for inducing remineralization. This study protocol describes a randomized clinical trial evaluating restorative treatment using an adhesive system containing 45S5 bioactive glass for MIH-affected teeth.
Methods
Restorations will be performed on the upper or lower first permanent molars in children with MIH aged 6–12 years. The inclusion criteria will include MIH teeth with post-eruptive enamel fractures that compromise the middle third of the dentin, with at least two surfaces of hypomineralized enamel near the cavity, without caries, pulpal, or periradicular involvement. Before treatment, children will complete the Child Perceptions Questionnaire 8–10 and 11–14 (CPQ8–10 and CPQ11–14). The teeth will be divided into two groups: a control group (commercial self-etching adhesive system: Clearfil SE Bond (CF) Primer + Bond) and an experimental group (CF Primer + experimental Bond using 10% 45S5 bioglass [Bond 45S5 10%]). Restorations will be made using composite resin, and quality will be assessed using digital radiographs (interproximal and periapical), intraoral photographs, and epoxy resin replicas. Clinical evaluation of the restorations will be performed immediately following the procedure (baseline) and after 1, 3, 6, and 12 months using the World Dental Federation (FDI) criteria. The impact of the treatment on the quality of life will be assessed after 3, 6, and 12 months through the re-administration of CPQ8–10 and CPQ11–14.
Discussion
45S5 bioactive glass is capable of enhancing the effect of materials on bone and dental structures, promoting remineralization. The results of this study may aid in the clinical management of patients with MIH, given the challenges of treating sensitive and compromised teeth and the difficulty in achieving long-term restorative success while addressing the individual patient needs.
Trial registration
Rebec, U1111-1259-1738. Registered on January 10, 2021.
Journal Article
Early Pleistocene enamel proteome from Dmanisi resolves Stephanorhinus phylogeny
The sequencing of ancient DNA has enabled the reconstruction of speciation, migration and admixture events for extinct taxa
1
. However, the irreversible post-mortem degradation
2
of ancient DNA has so far limited its recovery—outside permafrost areas—to specimens that are not older than approximately 0.5 million years (Myr)
3
. By contrast, tandem mass spectrometry has enabled the sequencing of approximately 1.5-Myr-old collagen type I
4
, and suggested the presence of protein residues in fossils of the Cretaceous period
5
—although with limited phylogenetic use
6
. In the absence of molecular evidence, the speciation of several extinct species of the Early and Middle Pleistocene epoch remains contentious. Here we address the phylogenetic relationships of the Eurasian Rhinocerotidae of the Pleistocene epoch
7
–
9
, using the proteome of dental enamel from a
Stephanorhinus
tooth that is approximately 1.77-Myr old, recovered from the archaeological site of Dmanisi (South Caucasus, Georgia)
10
. Molecular phylogenetic analyses place this
Stephanorhinus
as a sister group to the clade formed by the woolly rhinoceros (
Coelodonta antiquitatis
) and Merck’s rhinoceros (
Stephanorhinus kirchbergensis
). We show that
Coelodonta
evolved from an early
Stephanorhinus
lineage, and that this latter genus includes at least two distinct evolutionary lines. The genus
Stephanorhinus
is therefore currently paraphyletic, and its systematic revision is needed. We demonstrate that sequencing the proteome of Early Pleistocene dental enamel overcomes the limitations of phylogenetic inference based on ancient collagen or DNA. Our approach also provides additional information about the sex and taxonomic assignment of other specimens from Dmanisi. Our findings reveal that proteomic investigation of ancient dental enamel—which is the hardest tissue in vertebrates
11
, and is highly abundant in the fossil record—can push the reconstruction of molecular evolution further back into the Early Pleistocene epoch, beyond the currently known limits of ancient DNA preservation.
Palaeoproteomic analysis of dental enamel from an Early Pleistocene
Stephanorhinus
resolves the phylogeny of Eurasian Rhinocerotidae, by enabling the reconstruction of molecular evolution beyond the limits of ancient DNA preservation.
Journal Article
Frequencies of enamel hypomineralisation in permanent and primary molars in a medieval and early-modern-age population (7th − 17th c.) in Sains-en-Gohelle (Pas de Calais, France)
Molar Incisor Hypomineralisation (MIH) is defined as a qualitative demarcated enamel hypomineralisation defect of tooth enamel affecting at least one first permanent molar (FPM), often affecting permanent incisors. More recently, the term Hypomineralised Second Primary Molar (HSPM) was used to describe similar defects affecting second primary molars. Our observational study aimed at determining HSPM and MIH frequencies in a medieval and early-modern-age population population (Sains-en-Gohelle, France, 7th − 17th centuries) and compare it to the current worldwide and French prevalence values. To date, there are no other studies on this subject in France. European studies have been published, but the diagnosis of these pathologies is based solely on a visual examination. Our study differs from others by using objective diagnostic. microtomography and X-ray fluorescence. The use of these diagnostic methods allows differentiation between hypomineralised and taphonomic lesions. The frequencies of MIH and HSPM were, respectively, 12.3% and 13.3%. In fact, there were 10 individuals with at least one first permanent molar affected by MIH amongst the 81 individuals with at least one first permanent molar present, and 15 individuals with at least one second primary molar affected by HSPM among the 113 individuals with at least one second primary molar present.The presence of MIH and HSPM in ancient populations with frequencies respectively equivalent and higher than current worldwide averages renews the debate and questioning about the aetiological factors of these pathologies.
Journal Article
Evaluation of zinc oxide nanoparticle coated elastomeric modules and it’s effect on Streptococcus mutans concentration and enamel mineralization - A randomized split mouth trial
To assess the long term effects of zinc oxide (ZnO) nanoparticle coated elastomeric modules on S. mutans concentration and enamel mineralization among orthodontic patients over a period of one year. A total of 16 patients were recruited for this study. Either the left or right maxillary lateral incisor received the coated module. Group I : ZnO coated elastomeric modules (N = 16); Group II: Non-coated elastomeric modules (N = 16). S. mutans in plaque was assessed at the end of 3 months and one year using Rt -PCR. Enamel mineralization was assessed by laser fluorescence at the end of one year. Integrity of the ZnO nanoparticle coating over a period of one month on a weekly basis was also assessed. Independent t-test was done to find the significant difference between the bivariate samples and intra-group comparison was done using paired t-test. Pearson’s correlation was done to determine the relationship between the variables. For all the statistical tests, p < 0.05 was considered to be statistically significant. S. mutans concentration at the end of three months and one year was higher in the non-coated group compared to the coated group but it was statistically significant only at the end of one year (p value = 0.032). Laser fluorescence values was higher for the non-coated group compared to the coated group which showed statistical significance (p = 0.020). ZnO coating of the modules showed evidence of disintegration of the coating after two weeks, with further deterioration of the coating at the end of one month. As elastomeric modules are changed periodically, this appears to be a viable option, especially since the nanoparticle release would be around the most common area of plaque retention.
Journal Article