Search results for "Enamel"
showing 10 items of 277 documents
Clumped isotope thermometry of carbonate-bearing apatite: Revised sample pre-treatment, acid digestion, and temperature calibration
2016
Abstract It has recently been shown that the clumped isotopic composition (Δ47) of carbonate-bearing hydroxyapatite (CHAP) from teeth and bones reveals important information about the body temperature of vertebrates (Eagle et al., 2010, 2011). In this study we reinvestigate the temperature dependence of Δ47 in CHAP, extending the temperature range from 2 to 59 °C. In addition, the effects of chemical pre-treatment of CHAP on its bulk and clumped isotopic composition are studied. CHAP is best reacted with phosphoric acid at 90 to 110 °C minimizing the potential of evolved CO2 or reaction intermediates to re-equilibrate with traces of water in the acid environment. Reaction at 110 °C ensures …
Influence of different biomaterials on the viability of Aggregatibacter actinomycetemcomitans
2011
Abstract Objectives The aim of the present in vitro study was to evaluate the effects of different biomaterials used for regenerative periodontal surgery on the growth of the periodontopathogen Aggregatibacter actinomycetemcomitans . Methods Three commercially available biomaterials of synthetic origin (hydroxyapatite/beta-tricalcium phosphate, nanostructured hydroxyapatite paste, oily calcium hydroxide suspension), a bovine-derived xenograft as well as an enamel matrix derivative (EMD) were added in different concentrations to calibrated suspensions of A. actinomycetemcomitans ATCC 43718/33384 (serotype b/c). Equal aliquots (0.1 ml) for the viability assay were taken after 5 min, 1 h, 3 h,…
Zinc isotope variations in archeological human teeth (Lapa do Santo, Brazil) reveal dietary transitions in childhood and no contamination from gloves
2020
International audience; Zinc (Zn) isotope ratios of dental enamel are a promising tracer for dietary reconstruction in archeology, but its use is still in its infancy. A recent study demonstrated a high risk of Zn contamination from nitrile, and latex gloves used during chemical sample preparation. Here we assess the potential impact of the use of such gloves during enamel sampling on the Zn isotope composition of teeth from a population of early Holocene hunter gatherers from Lapa do Santo, Lagoa Santa, Minas Gerais, Brazil. We first examined the amount of Zn and its isotopic composition released from the gloves used in this study by soaking them in weak nitric acid and water. We compared …
Marginal integrity of low-shrinkage and methacrylate-based composite resins: Effect of three different hemostatic agents.
2015
Background: Moisture control is very important in restorative procedures in dentistry. Use of hemostatic agents helps control moisture; however, they might result in changes on enamel and dentin surfaces, affecting composite resin bond quality. The aim of this in vitro study was to evaluate the marginal microleakage of two different composite resins with the use of three different hemostatic agents. Material and Methods: Standardized Class V cavities were prepared on the buccal and lingual surfaces of 48 premolars with cervical margins 1 mm apical to the cementoenamel junction (CEJ). The samples were randomly divided into 8 groups. In groups 1 to 4, an etch-and-rinse adhesive (Adper Single …
Antibacterial, physical and mechanical properties of bonding agent containing synthesized Zinc Dimethacrylate
2019
Background The aim of this study includes synthesis of zinc dimethacrylate ionomer (ZDMA) by a new method, incorporate it into resin bonding and evaluate its antibacterial, physical and mechanical properties. Material and methods Resin adhesives containing 0 to 5% wt of ZDMA was produced and the following tests were accomplished: A: Antibacterial test: 1.Direct contact test. 2.Material aging; in both of them the bacterial colony counting were performed. B: Physical test: 1.Degree of conversion (D.C). 2.Evaluating the amount of released Zinc ion release in aqueous medium. C: Mechanical test: 1.Compressive strength test. 2.Shear bond test (enamel and dentine separately). The obtained results …
Impact of rare diseases in oral health
2016
Background Rare diseases (RD) are those that present a lower prevalence than 5 cases per 10.000 population. The main objective of this review was to study the effect on oral health in rare diseases, while the secondary objective of the study is theme upgrade. Material and Methods Comparative observational case-control studies were analysed and a systematic review was conducted in PubMed. Each rare disease listed on the statistical data record of the Health Portal of the Ministry of Equality, Health and Social Policies Board of Andalusia was associated with “oral health”. The variables studied included dental, oral mucosa and occlusion alterations, oral pathologies (caries, periodontal disea…
Cri du chat syndrome: A critical review
2009
A new syndrome was identified in 1963, when Lejeune et al. reported a genetic disease resulting from a partial or total deletion on the short arm of chromosome 5 (5p-) and named it the cri du chat syndrome (CdCS). This term makes reference to the main clinical feature of the syndrome, a high-pitched monochromatic cat-like crying, that usually disappears in the first years of life. CdCS is one of the most common chromosomal deletion syndromes in humans, with an incidence of 1:15.000-1:50.000 live-births. Our purpose was to review different aspects of this syndrome (concept, epidemiology, aetiology, clinical features,diagnostic methods and prognosis) emphasizing both: the breakthrough in this…
Effect of saliva contamination on bracket failure with a self-etching primer: A prospective controlled clinical trial
2010
Introduction The aim of this study was to evaluate in vivo the effect of saliva contamination at different stages of the bonding procedure on the bond failure rate and the adhesive remaining on teeth after debonding brackets bonded with a hydrophilic self-etching primer (Transbond Plus self-etching primer [TSEP], 3M Unitek, Monrovia, Calif). Methods This was a prospective controlled clinical trial. The sample consisted of 46 patients with similar treatment plans and mechanotherapies. Stainless steel brackets (n = 531) were bonded with TSEP. The patients were divided into 2 groups: contamination with saliva before TSEP application and contamination with saliva after TSEP application. In both…
Influence of the adhesive strategy in the sealing ability of resin composite inlays after deep margin elevation
2021
Background The aim of this study was to determine the influence of the gingival margin position and the adhesive strategy selected to perform deep margin elevation (DME) in marginal sealing of resin composite inlays by a nanoleakage test. Material and Methods 12 sound third molars were selected and expulsive MOD cavities for inlays were prepared. Experimental groups were established according to gingival margin location (enamel: 1 mm above cemento-enamel junction (CEJ), dentin: 1 mm below CEJ, or DME, and the adhesive strategy used to lute inlays and elevate the gingival margin. Therefore, the six experimental groups were: 1) Enamel + etch-and-rinse adhesive (ERA) Adper Scotchbond 1XT (SB1X…
Diagnosis and treatment of dens invaginatus with open apex in a young adult patient by using cone-beam computed tomography and operative microscope.
2021
BACKGROUND: Dens invaginatus is a developmental anomaly that can affect both deciduous and permanent dentition. The anomaly is caused by the invagination of the enamel organ into the dental papilla prior to the calcification of the dental tissues. The treatment option changes according to the classification, from the simple filling of the invaginated enamel area to root canal treatment with or without retrograde surgery, intentional re-implantation, or the extraction of the affected tooth. CASE REPORT: In this study we report a case of a maxillary lateral incisor invaginatus in a young adult patient. The periapical endoral X-ray showed the presence of a periapical radiolucency in tooth 22, …