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Biomedical subjects

G Piana

Publications and source records attributed to G Piana.

At least 19 recordsLinked to original sources
PubMed1996

Structural features of latex gloves in dental practice.

The aim of this study was to define from a morpho-structural point of view, using scanning electron microscopy, the features of various types of disposable latex gloves commonly used in Italian dental practice (Biogel D, Trend, Pagni, J&J, Latechnics, Pehasoft, Bantex). None of the brands examined was free from morphological flaws; however, while in some of these only slight depressions were found (Biogel D, Trend), in others (Latechnics, Bantex) there was a marked lack of homogeneity in the latex structure or real holes (Pehasoft). This study emphasizes the current difficulties faced by dentists in the search for safe working conditions.

Biocompatible Materials↗
PubMed1995

[Amalgam and the toxicological risks of mercury. A review of the argument].

The employment of dental amalgam in the area of conservative dentistry, in spite of representing an excellent therapeutic solution, is today undergoing criticism more frequently than before because of the potential toxicity of mercury regarding hyman health and environmental salubrity. Mercury is a metal having the tendency to evaporate at ambient temperature and it is just the inhalation of its vapor the most common form of exposure to mercury for man. The absorption may also may also occur through food ingestion or accidental swallowing of metal particles coming from dental amalgam fillings. Mercury poisoning usually turns out to be a chronic process which causes its major toxic effects at the expense of digestive, excretory and neurocentral apparatuses. Several authors have studied mercury exposure on the working places, including in their investigation persons operating in the dentistry departments: they found high levels of mercury existing both in tissues and in biological fluids in people affected by exposure, frequently accompanied by symptoms of chronic intoxication. More recent studies, however, do not fully confirm such conclusions and exclude that coming into contact with mercury vapor on the working place may be in connection with an increase of mortality. Exposure to mercury from amalgam for the most part occurs through ingestion of amalgam particles abraded from restored surfaces, inhalation of vapors generated during dental restorative procedures and deglutition of saliva into which corrosion products have dissolved.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

[Dentinal bonding systems and the tensile bond strength test].

The aim of the present study was to evaluate the tensile bond strength of four dentinal bonding agents (DBAs) to the dentin surface. Tensile bond test procedure was made using a universal testing machine. Human extracted third molars were mounted with self-curing acrylic resin in cylindrical molds. The dentin occlusal surface was ground with 320-grit silicon carbide abrasive paper. The DBAs were prepared according to manufacturers' directions and applied on the dentin surface. Cylindrical teflon tubes were placed on the dentin surface and filled with a microfilled resin. The samples were then stored in a humidifier at 37 degrees C for 24 h. Six specimens were prepared for each group. A statistically significant difference was observed among the four groups. It has been observed that certain materials showed a dentin bond value superior to cohesive value of composite resin.

Dental Cements↗
PubMed1990

[Glass-ionomer cements in Class V restorations].

The aim of the present study was to evaluate the effect of two different techniques of glass-ionomer application on the marginal microleakage in Class V restorations. Two types of composite resins were also used. Nonretentive Class V cavities were prepared at the cementum enamel junction of human extracted third molars. Glass-ionomer cements were applied with a chamfer technique or as base in the floor of the cavity. After restoration, the samples were stored in dye solution, sectioned and observed under optical stereomicroscope. The base technique for glass-ionomer cements showed less microleakage than the other restorative methods.

Composite Resins↗
PubMed1989

[Knowing pemphigus].

The classification, pathogenesis, clinical features and treatment of pemphigus are examined with emphasis' on the histopathological similarities of the elementary intraepithelial lesion and the histotopographical differences at epithelial level that differentiate the various types of pemphigus. In a detailed review of the pathogenesis of the condition, the circumstances propitious for the onset of pemphigus are identified as an HLA phenotype and the autoantigenic denaturation of the glycocalyx. The condition is described as vesicolobullous and is differentiated from similar bullous and non-bullous dermatoses. The most significant pictures of oral pemphigus are specified as are the basic elements of general and local treatment.

Autoimmune Diseases↗
PubMed1989

[Candida-host relationship: physiology and pathology].

The Authors give a detailed analysis of the potential virulence factors and possible pathogenic processes associated with candida. They qualify the interactions between local, general, natural and acquired defences, setting out the possible deficiency involved in the emergence of secondary candidiasis. They make a classificatory revision of forms of candidiasis on the basis of topographic, anatomo-pathologic criteria and of the course of the disease. They investigate the most significant aspects of the situations described especially in oral localization. An evaluation is made of chronic mucocutaneous candidiasis as a pathological affection in itself and in its correlation with H.I.V. infection.

Acquired Immunodeficiency Syndrome↗
PubMed1983

[Immunochemical determination of immunoglobulins and lysozyme in normal human saliva - principal assay technics].

We have studied a method to determine the concentrations of low level of immunoglobulins and lysozyme in saliva. The concentration of IgG, IgA and IgM in human whole saliva were measured by fluorimetric method and the concentration of lysozyme by turbidimetric method. The results of our study in 18 normal subjects (15 females and 3 males), have showed the geometric mean concentration (microgram/ml) IgG 5,1; IgA 177; IgM 2,6 and lysozyme 117.

Adolescent↗
PubMed1983

[A method for erythrocyte filtration].

Erythrocyte deformability is one of the most important factors on determining blood viscosity. Many microcirculation damages are caused by alteration of viscosity. We propose a method for evaluate erythrocyte filtration using Nucleopore membranes, to study erythrocyte deformability. Normal ranges are calculated in young healthy subjects. Mean filtration time is determined on 5 filtrations for every subject. Filtration rate is expressed by sec/ml and correlated whit haematocrit. The method is not easily utilizable, but it can be useful in the knowledge of the role of the erythrocyte deformability in the altered microcirculation.

Blood Viscosity↗