Search results for "tooth"
showing 10 items of 910 documents
Review of paleo-humidity parameters in fossil rodents (Mammalia): Isotopic vs. tooth morphology approach
2014
Paleoecology of fossil rodents is frequently inferred from the dental pattern of the teeth, attributing the habitat conditions of extant rodents to fossil species with similar dental pattern. This technique is common practice and has been in use for several decades. A relatively new technique is based on the carbon and oxygen isotope composition of the incisor enamel of fossil rodents to reconstruct paleoenvironmental scenarios. We combine these two methods, studying material from two Early Miocene Spanish sections, one in the Mediterranean coastal area and one in Northcentral inland Spain. Comparison of the humidity values obtained by means of these two proxies reveals discrepancies. There…
In-vitro regulation of odontogenic gene expression in human embryonic tooth cells and SHED cells
2012
The bud-to-cap stage transition during early tooth development is a time when the tooth-inducing potential becomes restricted to the mesenchyme. Several key genes, expressed in the mesenchyme at this stage, are an absolute requirement for the progression of tooth development. These include the transcription factors Msx1 and Pax9. The inductive potential of tooth mesenchyme cells is a key requisite for whole-tooth bioengineering and thus identification of cells that can retain this property following expansion in culture is an important as yet unresolved, goal. We show here that in-vitro culture of embryonic human tooth mesenchyme cells and SHED cells express low levels of PAX9 and MSX1 and …
Automated segmentation and description of the internal morphology of human permanent teeth by means of micro-CT
2020
High-resolution micro-computed tomography is a powerful tool to analyze and visualize the internal morphology of human permanent teeth. It is increasingly used for investigation of epidemiological questions to provide the dentist with the necessary information required for successful endodontic treatment. The aim of the present paper was to propose an image processing method to automate parts of the work needed to fully describe the internal morphology of human permanent teeth. One hundred and four human teeth were scanned on a high-resolution micro-CT scanner using an automatic specimen changer. Python code in a Jupyter notebook was used to verify and process the scans, prepare the dataset…
Early root surface colonization by human periodontal ligament fibroblasts following treatment with different biomaterials
2013
The present in-vitro study examined the effects of different biomaterials on early root surface colonization by human periodontal ligament (PDL) fibroblasts using confocal-laser-scanning-microscopy (CLSM).Fifteen periodontally-diseased teeth were extracted, treated with scaling/root planing and longitudinally cut to obtain 30 root fragments. Fragments were treated either with 24% EDTA following application of enamel matrix derivative (EMD), 24% EDTA or EMD only, nanocrystalline hydroxyapatite (NHA) paste or oily calcium hydroxide suspension (OCHS) for 1 h each. The analogue untreated root specimens served as controls. Root fragments were incubated with human PDL fibroblasts and cellular pro…
Response of periodontium to mineral trioxide aggregate and Biodentine: a pilot histological study on humans.
2018
Background The aim of this study was to investigate for the first time the histological response of human periodontium to mineral trioxide aggregate (MTA) and Biodentine. Methods Six patients scheduled for implant full-arch rehabilitation were randomly assigned to one of the two test groups: MTA or Biodentine treatment. For each patient, two teeth scheduled for strategic extraction were randomly assigned either to the test or to the control treatment. A lateral perforation was drilled on the root and either repaired with MTA/Biodentine or filled with gutta-percha(control). Three months later, the teeth were extracted along with the coronal third of the alveolar bone and a portion of gingiva…
Remineralization effects of conventional and experimental ion-releasing materials in chemically or bacterially-induced dentin caries lesions
2019
Abstract Objectives The aim of this study was to evaluate the remineralization effects of conventional and experimental ion-releasing materials on different artificial dentin carious lesions. Methods Forty human dentin discs were submitted to different demineralization protocols for simulated caries lesion: (D1) Shallow chemically-induced caries, (D2) deep chemically-induced caries, (D3) deep bacterially-induced caries. Each disc was divided in five parts; one of those served as baseline control. The remaining parts of each disc (n = 12–16/group) were treated using the following materials: EXP, an experimental resin-based bioactive material consisting of a self-etch primer and an adhesive c…
Mineral trioxide aggregate in primary teeth pulpotomy. A systematic literature review
2009
Evidence-based dentistry is a critical evaluation, awareness of the available evidence to improve decision making about the care of individual patients and / or communities. Objective: To systematically analyze the available scientific literature on clinical and radiographic results of two materials used in pulpotomy in primary teeth: formocresol and mineral trioxide aggregate. Materials and methods: It was identified relevant publications through a search of electronic databases such as MEDLINE (Ovid) and The Cochrane Library. To be included in the review, studies had to define the material used in child patients with pulp exposure by caries or tooth-alveolar trauma. Results: Of the 21 art…
Bioactivity of bioceramic materials used in the dentin-pulp complex therapy : a systematic review
2019
Este es el artículo que se ha publicado de forma definitiva en: https://www.mdpi.com/1996-1944/12/7/1015 Dentistry-applied bioceramic materials are ceramic materials that are categorized asbioinert, bioactive and biodegradable. They share a common characteristic of being specificallydesigned to fulfil their function; they are able to act as root canal sealers, cements, root repair or fillingmaterials. Bioactivity is only attributed to those materials which are capable of inducing a desiredtissue response from the host. The aim of this study is to present a systematic review of availableliterature investigating bioactivity of dentistry-applied bioceramic materials towards dental pulp stemcel…
Microleakage comparison of glass-ionomer and white mineral trioxide aggregate used as a coronal barrier in nonvital bleaching
2011
Objectives: There is some evidence that the pH at the root surface is reduced by intracoronal placement of bleaching pastes, which is known to enhance osteoclastic activity. Therefore, it is recommended that a protective barrier be used over the canal filling to prevent leakage of bleaching agents. Glass-ionomer (GI) is commonly used as a coronal barrier before nonvital bleaching. Because mineral trioxide aggregate (MTA) creates high alkalinity after mixing with water, using MTA as a protective barrier over the canal filling may not only prevent leakage of bleaching agents and microorganisms, but may prevent cervical resorption. The aim of this study was to evaluate sealing ability of white…
The Discoloration effect of White Mineral Trioxide Aggregate (WMTA), Calcium Enriched Mixture (CEM), and Portland Cement (PC) on Human Teeth
2017
Background The aim of this study was to evaluate the discoloration induced by CEM cement, Portland cement (PC) and MTA mixed with propylene glycol (MTA-PG) in comparison to White MTA. Material and methods Ninety extracted premolar and canine teeth were resected 2 mm below the CEJ. The coronal part of crown was prepared with peeso reamer and Gates-Glidden drills, and the specimens were randomly divided into 4 experimental (n=20) and one control (n=10) groups. The tooth crowns in experimental groups 1 to 4 were filled with White MTA, PC, CEM cement and MTA-PG, respectively; and in group 5, the teeth were kept empty. After incubation, digital photographs of teeth were acquired at 4 time points…