Search results for "amalgam"
showing 10 items of 38 documents
Determination of susceptibility to sensitization to dental materials in atopic and non-atopic patients
2010
Introduction: Some studies report that atopic patients have a greater frequency of delayed-type sensitization than non-atopic patients. Objective: To determine the influence of the atopic condition on delayed sensitization to dental materials. Design: cross-sectional study. Methods: Forty (40) atopic subjects and forty (40) non-atopic subjects, of both sexes, between 20 and 65 years of age were included. The determination of delayed sensitization to dental materials was performed using patch test. An oral exam was also carried out to check for lesions of the oral mucosa. Results: 61.25% of the patients were positive for delayed-type sensitization to one or more allergens, being palladium ch…
Differential metallothionein expression in oral lichen planus and amalgam-associated oral lichenoid lesions
2017
Background Oral lichen planus (OLP) is a chronic inflammatory disease mediated by T cells, which manifests as reticular (white) or erosive (red) lesions, that are eventually painful. Oral lichenoid lesion (OLL) are distinguished from OLP by the presence of precipitating factors. The aim of this study was to evaluate whether the presence of metallothionein, which is involved in anti-apoptotic pathways and the anti-oxidative response, could serve as a differential diagnostic for OLP and OLL. Material and Methods We evaluated the expression of metallothionein in 40 cases of OLP and 20 cases of OLL using immunohistochemistry. Results and Conclusions White OLP has higher concentrations of metall…
Oral lichenoid lesions associated with amalgam restorations : a prospective pilot study addressing the adult population of the Basque Country
2011
Oral lichenoid lesions (OLLs) are linked to a heterogeneous group of pathologies involving the oral mucosa that cannot be distinguished from the oral lichen planus excepting the fact that direct causal factors such as silver amalgam restorations (SARs) can be allocated to them. Purpose: To analyze the prevalence of mucosal lesions associated with SAR in a group of SAR carrying patients in the Basque Country. Study D esign: A clinical prospective study was carried out on 100 adult patients over 30 years of age at the UPV/ EHU Clinical Odontology Service whose rear teeth had at least one SAR. Patients were identified and mucosal lesions and amalgam restorations were characterized. Patch tests…
Are mucous retention cysts and pseudocysts in the maxillary sinus a risk factor for dental implants? A systematic review
2020
Background Mucous retention cysts and pseudocysts of the maxillary sinus are benign lesions present in up to 13% of adult patients. Different surgical approaches for sinus lift and dental implant placement in the presence of these lesions have been proposed. Material and Methods A systematic review was performed following the PRISMA statement recommendations to answer the PICO question: Does the aspiration or removal of mucous retention cysts/pseudocysts before or during sinus lifting and dental implant placing, affect the survival of the implants? The study was pre-registered in PROSPERO (CRD42020185528). Included articles quality was assessed using the “NIH quality assessment tool” and “T…
A comparative study of silver amalgam and compomer as retrograde filling materials in periapical surgery
2008
Objective: A comparative study is made of the histological effects of silver amalgam versus compomer (Dyract®) 90 days after placement as retrograde filling materials in experimental animals. Method: Six Beagle dogs were used, with total pulpectomy and orthograde material filling followed by periapical surgery of the 6 upper and 6 lower incisors (for a total of 72 teeth). Thirty-six teeth corresponded to the right side and were filled with the control material (silver amalgam), while the 36 teeth on the left side were filled with the compomer study material (Dyract®). After three months the animals were sacrificed and the histological study was carried out, with evaluation of bone formation…
Two-carbon bridge substituted cocaines: enantioselective synthesis, attribution of the absolute configuration and biological activity of novel 6- and…
1999
In an effort to learn more about the general structure-activity relationships of cocaine with the aim to elucidate those structural features that might confer antagonistic properties to such analogues, we describe herein our synthetic efforts to prepare two-carbon bridge functionalized (methoxylated and hydroxylated) analogues. Our approach makes use of a modification of the classical Willstatter synthesis of cocaine: Mannich type cyclization of acetonedicarboxylic acid monomethyl ester with methylamine hydrochloride and 2-methoxysuccindialdehyde in a citrate buffer solution afforded the 6- and 7-substituted 2-carbomethoxy-3-tropinones 3a,b and 4a,b in approximate yields of 64%. Reduction o…
Clinical and radiological course in apicoectomies with the Erbium : YAG LASER
2007
A study is made of the efficacy of the Erbium: YAG laser in granulomatous periapical lesions, based on clinical and radiographic controls. The study comprised a series of 45 patients amenable to periapical surgical treatment of incisors, canines and premolars. A conventional surgical technique was used, with silver amalgam retrograde filling and irradiation of the bone defect and remnant root cement with the Erbium: YAG laser. Clinical and radiographic controls were made during 24 months, assessing the absence of symptoms and the presence of pain, swelling or fistula and ossification of the lesions, respectively. The clinical course proved asymptomatic in 95.5% of the cases. As regards remo…
Studien zum Vorgang der Wasserstoffübertragung, 54. Mechanismus und Grenzen der Clemmensen-Reduktion des Acetophenons und verwandter Verbindungen
1978
Bei der Reduktion von Acetophenon nach Clemmensen entstehen auser Ethylbenzol (1; Vier-Elektronen-Ubergang) in von den Reaktionsbedingungen abhangigen Mengen das Hydrodimerisierungsprodukt 2,3-Diphenyl-2,3-butandiol (2; Ein-Elektronen-Ubergang) und dessen Umlagerungsverbindungen 3 und 4, aber weder 1-Phenylethanol noch Styrol (Zwei-Elektronen-Ubergang). Temperatur, Saurekonzentration, Saureart, Reduktionsmittel (amalgamiertes Zink, Zinkamalgam, Cadmium, Zink-Cadmium-Legierung, Cadmiumamalgam, Magnesiumamalgam, Blei, Zink, Blei-Legierung) bestimmen die Anteile der gebildeten Reduktionsprodukte 1 — 4. 1-Phenylethanol und Styrol konnen unter Clemmensen-Bedingungen partiell in Ethylbenzol (1) u…
Comparative studies on cytotoxic effects of dental amalgams and alternative alloys according to ISO standards in vitro
1995
Deleterious effects of dental alloys, especially those of dental amalgams, have become an important issue in current discussions on biomaterials. Cytotoxicity and further related risks of amalgams are discussed in a controversial way in the literature without leading to a final conclusion. There is still a need for basic clinical and pre-clinical research, especially with respect to the wide distribution of dental amalgams. Standardized methods of cytotoxicity testing have been established by the ISO. It was the aim of the present study to detect and compare possible cytotoxic effects of dental amalgams and alternative non-amalgam alloys in vitro. According to the ISO standards, direct cont…
Chapter 1 Amalgams, Colimits, and Conceptual Blending
2018
This chapter is a theoretical exploration of Joseph Goguen’s category-theoretic model of conceptual blending and presents an alternative proposal to model blending as amalgams, which were originally proposed as a method for knowledge transfer in case-based reasoning. The chapter concludes with a generalisation of the amalgam-based model by relating it to the notion of colimit, thus providing a category-theoretic characterisation of amalgams that is ultimately computationally realisable.